LEARNING HUB.TZ

BIOLOGY EXAMINATION FORM TWO

TOPICAL EXAMINATIONS.

NUTRITION

NAME………………………………………..CLASS………………………………………….……………TIME: 2¹/₂HRS

INSTRUCTIONS:-

1. This paper consists of sections A, B and C

2. Answer all questions

3. All answers must be written in the spaces provided

4. All writings should be in blue/black inks except for drawings that should be in pencils

SECTION A.

1. Multiple Choice questions.

1. Below are some of diets taken in East Africa, which one of them could easily cause

kwashiorkor in children when taken for quite a long period?

1. Millet with fish

2. Cassava with beans

3. Rice with meat

4. Bananas with green vegetables

2. A person whose diet lacks iodine is likely to develop a nutritional disorder known

As

A. beriberi

B. rickets

C. night blindness

D. goitre.

3. A person with a deficiency of vitamin C is likely to become a victim of

A. beriberi

B. rickets

C. night blindness

D. scurvy.

iv) Below are some of diets taken in East Africa, which one of them could easily cause

kwashiorkor in children when taken for quite a long period?

1. Millet with fish

2. Cassava with beans

3. Rice with meat

4. Bananas with green vegetables

5. A food sample which was tested by boiling with Benedicts or Fehlings solution gave an orange precipitate. This showed that the food sample contained

A. reducing sugar

B. fats

C. protein

D. sucrose.

5. A person with a deficiency of vitamin C is likely to become a victim of

A. beriberi B. rickets

C. night blindness D. scurvy.

vii) Which part of a leaf has a large surface area for absorption of sunlight?

1. Petiole

2. Lamina

3. Stomach

4. Apex

5. Which of the following is not a traditional method of food preservation?

1. Canning

2. Curing

3. Drying

4. Smoking

5. The first site of digestion of protein is in the,

1. Mouth

2. Oesophagus

3. Stomach

4. Small intestine

5. Bile is produced in the

1. Pancreas

2. Stomach

3. Gall bladder

4. Liver

1. Matching items questions.

LIST A

LIST B

Waste excreted from the bowels Wave-like muscular contraction that push food along the oesophagus Connect the mouth to the stomach Grind the food Absorbs water from undigested and indigestible food materials. Waste is stored here ready to leave the body Preservation of food using honey Break down of disaccharides into monosaccharides Minerals which are required in very small amounts Break down of water molecules by use of sunlight

Carbondioxide fixation Photolysis Macro-elements Trace-elements Hydrolysis Condensation Curing Smoking Duodenum Oesophagus Rectum Molars Peristalysis Pyloric sphincter Canines Faeces Stomach.

SECTION B.

3.(a)explain briefly how you would carry out the following tests

1. Millons test

2. Reducing sugar

3. Starch

b) Give the properties of the following food substance?

i) Monosaccharides

ii) Disaccharides

4. Polysaccharides

4. (a) outline the adaptation of ileum in digestion and absorption of food.

b) mention the role of the following in digestion,

i) hydrochloric acids

ii) bile

iii) saliva

5. (a) distinguish between;

i) Food preservation and food storage

ii) refrigeration and freezing

iii) curing and smoking

b) Explain how the following methods can be used to preserve food

i) Smoking

ii) Pasteurization

iii) Using additives

6. a) Name at least five vitamin deficiency diseases.

b) i)What is a balanced diet?

ii) List six components of a balanced diet.

7. a) Name the three elements that form carbohydrates.
(b) Briefly state two properties of polysaccharides.

8. (a) What are the building blocks of proteins?

2. Distinguish between first class proteins and second class proteins.

3. State four functions of lipids in the human body.

9. A team of researchers went to a village near Tukuyu, Mbeya and found a five year old boy with the following symptoms:

• The stomach was protruding. • The skin was dry, flaky and rough.

• The hair was reddish and fell off easily. • The boy had no appetite.

(a) (1) Name the disease that the boy was suffering from.

2. What deficiency caused the disease?

3. Mention other disorders the boy was likely to be having.

4. What advice would you expect the researchers gave to the parents of the boy?

(b) Suggest the type of diet, which the boy may have been eating.

10. a) list two functions of digestive system

b) distinguish between mechanical and chemical digestion

c) which enzymes completes the digestion of protein in the ileum

LEARNING HUB.TZ

BIOLOGY EXAMINATION FORM TWO

TOPICAL EXAMINATIONS.

HUMAN DIGESTIVE SYSTEM.

NAME………………………………………..CLASS…………………………………………….………TIME: 2¹/₂HRS

INSTRUCTIONS:-

1. This paper consists of sections A, B and C

2. Answer all questions

3. All answers must be written in the spaces provided

4. All writings should be in blue/black inks except for drawings that should be in pencils

SECTION A.

1. MULTIPLE CHOICE QUESTIONS.

1. Which of the following food substance starts the process of digestion in mouth?

1. Protein

2. Lipids

3. Carbohydrates

4. Vitamins

2. The end product of digestion of protein is;

1. Fatty acids and glycerols

2. Amino acids

3. Peptides

4. Glucose

3. Which of the following digestion activity do not occur in the mouth?

1. Mechanical break down of food

2. Conversion of starch into maltose

3. Mixing food with saliva

4. Brake down of protein

4. Movement of food down the oesophagus is aided by;

1. Gravity

2. Peristalysis

3. Breathing

4. Swallowing

5. The role of the tongue in digestion of food is;

1. Mix food

2. Swallow food

3. Role food into bollus

4. Chew food.

6. Bile is produced in the

1. Gall bladder

2. Liver

3. Duodenum

4. Pancrease

7. Absorption of amino acids takes place in;

1. Lacteal

2. Blood cappilaries

3. Lymphatic system

4. Epithelium

8. Which of the following glands secretes both digestive juice and enzyme?

1. Salivary gland

2. Adrenal gland

3. Sweat gland

4. Pancrease

9. Which of the following substances is not found in the stomach?

1. Ptyalin

2. Lipase

3. Renin

4. Hydrochloric acid

10. In mammals, the organ that acts as a reservoir of carbohydrate is?

1. Pancreas

2. Liver

3. Spleen

4. Stomach.

2. MATCHING ITEMS QUESTIONS.

LIST A	LIST B
The substances that slowdown the action of enzymes. Wavelike movement of food down the alimentary canal Muscle valve found at the entrance of duodenum Breakdown of fats into small droplets Inactive form of pepsin A structure for absorption of food Bacteria infection of the gum A term used to describe the infections of the teeth A wound found in stomach Contain secretions with three enzymes	Bile Enterokinase Propepsin Pro-renin Cardiac sphincter Pyrolic sphincter Peristalysis Emulsification Hydrolysis Periodontal disease Ulcers Bacteria Dental carries Pepsinogen Villus Globlets

3. a) Mention the components of human digestive system

b) Give the meaning of the following terms as used in this topic

i) Digestion

ii) Absorption

iii) Assimilation

iv) Ingestion

v) Egestion

4. a) Briefly explain the role of the following in the process of digestion?

i) Teeth

ii) Tongue

iii) Saliva

b) Explain the nature of digestion that takes place in the mouth

5. a) Briefly explain how the food moves down the alimentary canal

b) Explain the adaptations of the stomach in the process of digestion

c) Mention the role the following in digestion

i) Hydrochloric acid

ii) Pepsin

iii) Rennin

iv) Mucus.

6. a) What is the work of the liver in digestion?

b) Mention four components of pancreatic juice and state their roles

7.a) briefly explain the role of the ileum in the process of digestation

b) Mention the all end products of the process of digestion.

8.a) Explain the adaptations of the ileum in the absorption of food.

b) Draw and label the structure of the ileum.

9. Discuss the main differences between the digestive system of ruminants and human beings

10. Describe the main disorders that affect human digestive system

LEARNING HUB.TZ

BIOLOGY EXAMINATION FORM ONE

TOPICAL EXAMINATIONS.

FOOD PROCESSING,PRESERVATION AND STORAGE EXAMINATION

NAME………………………………………..CLASS…………………………………………………TIME: 2¹/₂HRS

INSTRUCTIONS:-

1. This paper consists of sections A, B and C

2. Answer all questions

3. All answers must be written in the spaces provided

4. All writings should be in blue/black inks except for drawings that should be in pencils

SECTION A. 20 MARKS.

1. MULTIPLE CHOICE QUESTIONS.

1. Food processing means,

1. Treating food substances and make palatable and stay long

2. Converting food to another form

3. Keeping food substances in their original forms

4. Adding preservatives to food

2. Food preservation means

1. Treating food substances and make palatable and stay long

2. Converting food to another form

3. Keeping food substances in their original forms

1. Adding preservatives to food

3. Which of the following is not a preservative?

1. Honey

2. Salt

3. Organic acid

4. Pepper

4. Which of the following does not support the growthof micro-organism?

1. Sugar

2. Moisture

3. Oxygen

4. Warmth

5. Which of the following is not a traditional method of food preservation?

1. Smoking

2. Freezing

3. Boiling

4. Pickling

6. Which of the following food substance can be preserved by boiling?

1. Cereals

2. Fish

3. Meat

4. Vegetables

7. Baked beans can best be preserved by using,

1. Canning

2. Bottling

3. Boiling

4. Freezing

8. Sodas, juices and tomato sources can be preserved by:

1. Freezing

2. Boiling

3. Bottling

4. Canning

9. Adding flavorings in food assist in;

1. Making food appealing to eat

2. Make food stay longer

3. Promotes absorption of water

4. Improves appetite

10. One disadvantage of traditional methods of food preservation is that;

1. They are costly

2. Need high technology

3. Alter texture, taste and colour of food

4. It is expensive.

2. MATCHING ITEMS QUESTIONS.

LIST A

LIST B

Treating food in order to make them palatable and prolong their life Keeping food for future use without getting spoiled. Keeping food in their original form or condition and prevent it from getting spoilt. Preservation using honey Preservative used to prevent bacteria growth Chemical substances added to food but do not alter nutritional value Storing food at a temperature of below -200c Suitable for preservation of soft drinks Uses high technology and used in towns Required for growth of micro-organisms.

Food storage Food preservation Food processing Pickling Covering Water and air Water air and moisture Good PH Modern methods Traditional methods Food additives Freezing food Use of fridzer Bottling Canning Salt

3. A) Define the following terms

1. Food preservation

2. Food processing

3. Food storage

b) Explain the importance of food processing and preservation

4. Briefly explain the following methods of food preservation. In each give an example of food preserved.

a) Boiling

b) Smoking

c) Salting

d) Pickling

e) Drying

5. Describe the following methods of modern food preservation

i) Freezing

ii) Bottling

4. Canning

iv) Refrigeration.

6. Define and explain the following terminologies

i) Food additives

ii) Flavouring

iii) Colouring

iv) Bulking

v) Preservatives.

7. Outline the differences between food preservation and food processing.

8. Explain how each of the following foods can be preserved.

i) Meat

ii) Fish

iii) Cereals

iv) Cassava

v) Mango juice.

LEARNING HUB.TZ

BIOLOGY EXAMINATION FORM TWO

TOPICAL EXAMINATIONS.

NUTRITION IN PLANTS.

NAME………………………………………..CLASS…………………………………………….………TIME: 2¹/₂HRS

INSTRUCTIONS:-

1. This paper consists of sections A, B and C

2. Answer all questions

3. All answers must be written in the spaces provided

4. All writings should be in blue/black inks except for drawings that should be in pencils

SECTION A. 20 MARKS.

1. MULTIPLE CHOICE QUESTIONS

1. In plants most photosynthesis occur in the;

1. Palisade cells

2. Spongy mesophyll

3. Upper epidermis of the leaf

4. Guard cells

2. The role of light in photosynthesis is to

1. Form ATP

2. Form ADP

3. Cause photolysis

4. Form ATP and cause photolysis

3. Which of the following parts of a leaf does not have chloroplast?

1. Guard cell

2. Palisade cell

3. Cuticle

4. Spongy mesophyll

4. The main product of photosynthesis is transported away by

1. Phloem

2. Xylem

3. Veins

4. Vascular bundles

5. The following are the requirements for the process of photosynthesis

1. Light, water, chlorophyll and oxygen

2. Chlorophyll, oxygen, carbon dioxide and water

3. Carbon dioxide, light, chlorophyll, and water

4. Water, carbon dioxide, sugar and light

6. The dark stage of photosynthesis takes place in the;

1. Stroma

2. Grana

3. Matrix of the chloroplast

4. Cytoplasm

7. What is the main end product of photosynthesis?

1. Oxygen

2. Water

3. Energy

4. Glucose

8. The rates of photosynthesis are affected by the following factors except one, which one?

1. Temperature

2. Water

3. Carbon dioxide

4. Chlorophyll

9. Which of the following is a micronutrient?

1. Manganese

2. Zinc

3. Phosphorus

4. Copper

10. The storage organ for carrot is,

1. Bulb

2. Tap root

3. Stem tuber

4. Corm

2. Matching items questions.

LIST A

LIST B

Mineral required in small quantities Broad part of a leaf that contains photosynthetic tissues A term used to describe both xylems and phloem Responsible for opening and closing of stomata Light stage of photosynthesis takes place here. Break down of water into hydrogen ions and oxygen Carbon dioxide combines with oxygen Chemical form in which energy is stored The storage organ of cocoyam Transport of manufactured food from the plant leaves to other parts.

Vascular bundles Translocation Lamina Petiole Trace elements Macroelements Grana Stroma Guard cells Palisade cells ATP ADP Bulbs Root tuber Corms Hydrolysis Photolysis Carbon dioxide fixation

SECTION B.

3.A) define the following terms

1. Photosynthesis

2. Photolysis

3. Carbondioxide fixation

b) Mention the raw materials for the process of photosynthesis

4. a) Write the overall equation for the process of photosynthesis

b) Differentiate between the light stage and dark stage of photosynthesis

c) Differentiate between macro-nutrient and micro-nutrients

5. a) Name the organ of the plant where the process of photosynthesis takes place.

b) Describe the structure and adaptations of the leaf to the process of photosynthesis

c) A part from the leaf, mention other parts where the process of photosynthesis can take place.

6. Briefly explain the roles of the following parts of the leaf

i) The cuticle

ii) Epidermis

3. Stomata

4. Mesophyll

7. a) What is the functions of the guard cell?

b) Give the adaptations of the guard cell to the process of photosynthesis

c) Briefly explain the mechanism of opening and closing of stomata

8. Describe in detail what happens during the light and dark stage of photosynthesis

9. a) Explain the importance of photosynthesis in nature

10. Discuss the main storage organs used by plants to store food after photosynthesis

LEARNING HUB.TZ

BIOLOGY EXAMINATION FORM TWO

TOPICAL EXAMINATIONS.

BALANCE OF NATURE.

NAME………………………………………..CLASS………………………………………….……………TIME: 2¹/₂HRS

INSTRUCTIONS:-

1. This paper consists of sections A, B and C

2. Answer all questions

3. All answers must be written in the spaces provided

4. All writings should be in blue/black inks except for drawings that should be in pencils

SECTION A. 20 MARKS.

1. Multiple choice questions.

1. In parasitism

1. both the parasite and the host benefit

2. both the parasite and the host lose

3. the parasite benefits while the host loses

4. the parasite loses while the host benefits.

2. Carbon dioxide is reduced in the atmosphere through

1. volcanic activities

2. burning of organic matter

3. respiration

4. photosynthesis.

iii) A vulture feeds on dead bodies of animals. The vulture is best described as

A. an omnivore B. a carnivore

C. a decomposer D. a scavenger.

iv) Which of the following is an example of a mutualistic relationship?

1. A caterpillar eating tomato plant.

2. A flowering plant and its pollinators.

3. A plasmodium inside the human body.

4. A tick and a cow.

v) When two organisms live together for their mutual benefit the relationship is called

1. commensalism

2. symbiosis

3. epiphytism

4. saprophytism.

vi) Which of the following apply in a balanced grassland ecosystem?

1. There are more consumers than producers.

2. Decomposers act on producers only.

3. Producers and consumers are usually in equal numbers.

4. Producers are more numerous than consumers.

vii) Which of the following groups of organisms is not a producer?

1. Planktonic algae.

2. Cyanobacteria.

3. Green plants.

4. Fungi.

viii) Light from the sun is never

1. absorbed by the consumers

2. reflected back

3. absorbed by the clouds

4. absorbed by the producers.

ix) Which of the following ecological statements about cattle and goats is most correct?

1. Cattle are more efficient in assimilation of food materials taken in as compared to goats.

2. They are both herbivores but goats are grazers while cattle are browsers.

3. Cattle are mainly grazers while goats are browsers.

4. The goats are monogastric while cattle are ruminant.

x) Green plants are known as producers because,

A. They make their food from simple substances

B. They produce green leaves

C. contain fruits and seeds

D. Produce green leaves.

2. Matching items questions.

LIST A

LIST B

Interconnected food chains The living components of the environment Organism that make organic food molecules from carbon dioxide water and inorganic raw materials A series of organism through which energy is passed in form of food All living and non living things that occur naturally on earth Interaction that is beneficial to all organisms involved Organism occupying the final trophic level Interaction in which one organism captures, kills and feeds on another Temperature, wind, light soil water atmospheric pressure and altitude Converts nitrogen gas into nitrates.

Rhizobium Azobacter Biotic component Predation Commensalism Food web Producers Neutralism Water cycle Food chain Natural environment Competition Carbon cycle Mutualism Decomposers Parasitism.

3. (a) Name two examples of leguminous plants.

(b) The swelling shown on the contain microorganisms.

1. Name these microorganism

2. What is the importance of these microorganism the plant?

3. What term is used to describe the relations between the plant and microorganisms?

4. (a) Give the name of:

1. The bacteria that cons nitrates into nitrites a ammonia.

2. A nitrifying bacterium that converts ammonia in nitrites.

3. A nitrifying bacterium converts nitrates into nitrites.

(b) State two ways through nitrogen is made available plant.

5. a) Briefly explain the following terms;

i) Trophic level

ii) Food chain

3. food web

b) With examples, briefly explain how the following interactions of living organisms takes place

i) Predation

ii) Parasitism

6. a) With examples state the meaning of abiotic and biotic factors of the environment

B) i) Differentiate the term food chain from trophic level

ii) Construct a food chain by using the organisms below, grass, bacteria, lion and zebra.

7. Briefly discuss the role played by each of the following in an ecosystem.

1. Green plants.

2. Bacteria and fungi.

8. An ecologist carried out a survey to estimate the number of organisms in a certain dam. The following table shows the record of the survey.

Organisms	Estimated number
Microscopic algae	450,000
Small fish	290
Mosquito larvae	5,500
Crocodiles	10
Large fish	160

(a) Which of the above organisms are called the

1. Producers?

2. Primary consumers?

3. Consumers of the last order?

(b) Which organism is likely to get finished first in the dam? Give a reason to support your answer.

(c) Draw a possible food web that shows the energy flow in the dam.

LEARNING HUB.TZ

BIOLOGY EXAMINATION FORM TWO

TOPICAL EXAMINATIONS.

TRANSPORT OF MATERIALS

NAME………………………………………..CLASS………………………………………….………..……TIME: 2¹/₂HRS

INSTRUCTIONS:-

1. This paper consists of sections A, B and C

2. Answer all questions

3. All answers must be written in the spaces provided

4. All writings should be in blue/black inks except for drawings that should be in pencils

-

SECTION A.20 MARKS.

1. Multiple choice questions

1. The removal of a bark from the trunk of a tree kills the tree because the

1. supply of food to the roots is cut off

2. supply of carbon dioxide to the leaves is cut off

3. supply of water to the leaves is cut off

4. trunk loses the required strength and protection.

ii) An epidermal cell from a leaf was put in a hypertonic solution. After sometime the cell could be said to be

A. crenated B. turgid

C. flaccid D. deplasmolysed.

iii) Which of the following blood vesseles contains blood rich in dissolved food substances?

1. Hepatic portal vein

2. Aorta

3. Renal vein

4. Mensenteric artery

iv) The following blood vessels carry oxygenated blood except the

1. pulmonary vein

2. aorta

3. venacava

4. coronary artery.

v) A patient having blood group B can receive blood from a donor who belongs to

1. group B only

2. group 0 only

3. group B or group 0

4. group AB only

vi) Blood group AB is referred to as

1. antibody

2. antigen

3. universal donor

4. universal recipient.

vii) Which of the following sets present in mammalian blood is directly concerned with direct combating diseases?

1. Red blood cells.

2. Platelets and antibodies.

3. White blood cells and red blood

cells.

4. White blood cells and antibodies.

viii) Which of the following is not a function of the blood?

1. Secretion of hormones.

2. Natural healing of wounds.

3. Transport of gases to and from the tissues.

4. Regulation of body temperature.

ix) Three components of blood important in blood clotting are

1. leucocytes, thrombocytes and fibrinogen

2. thrombin, fibrinogen and thrombocytes

3. thromboplastin, thrombocytes and fibrinogen

4. erythrocytes, leucocytes and thrombocytes.

x) All of the following are suspended in the plasma except......................

A. Red blood cells

B. Platelets

C. Capillaries

D. White blood cells

2. Matching items questions.

LIST A

LIST B

Continous column of water from the roots to the leaves. Loss of water from the stems in form of droplets. Transport of food substances from leaves to other parts of plants. Solution with equal concentration as surrounding regions. The process that occurs when blood cell gain water and burst. Prevents back flow of blood into left ventricle. The clumbing together of blood The hardening of arteries Movement of fluid in vessels in large quantities The difference in concentration of molecules between two regions.

Osmosis Diffusion gradient Semi-permeable membrane Hypotonic solution Isotonic solution Mass flow Active transport Translocation Transport Guttation Transpiration Biscuspid valves Tricuspid valves Semi lunar valves Thrombosis Arteriocleriosis Haemolysis Crenation Transpiration stream Transpiration pull

3. Distinguish between the following terms:

1. Diffusion and osmosis.

2. Hypertonic solution and hypotonic solution.

3. Plasmolysis and haemolysis.

4. Turgor pressure and wall pressure.

5. Osmotic pressure and osmotic potential.

4. Define the following terms:

1. Mass flow

2. Isotonic solution

3. Deplasmolysis

4. Turgid

5. Flaccid

5. A) What are the factors affecting the rate of osmosis?

2. Explain the factors that affect the rate of active transport.

5. A) explain what would happen if;

1. Spleen and tonsils are removed from the body

2. Capillaries had thick walls

3. Left ventricles had thin walls

b) Give reasons why:

i) Small organisms such as amoeba do not need elaborate gaseous exchange system

ii) The left ventricle has a muscular thick wall than the right ventricle

iii) Blood in arteries flows in pulses

5. A) What is blood transfusion?

b) Explain the considerations to be taken before blood transfusion is carried out.

c) State two functions of mammalian blood other than transport of substances.

5. A) Define the following terms;

1. Capillarity

2. Transpiration pull

3. Root pressure

4. Transpiration stream

b) Differentiate between cohesion and adhesion forces.

9. Answer the following questions briefly;

i) Explain four environmental and plant factors that affect the rate of transpiration

ii) Mention and explain factors facilitate the water uptake of water in plants

10 (a) Differentiate between the following terms

1. Osmosis and diffusion

2. Hypotonic and hypertonic solution

3. Passive and active transport.

b) State the role of the following in photosynthesis.

i) water

ii) sunlight

4. Carbon dioxide

LEARNING HUB.TZ

BIOLOGY EXAMINATION FORM TWO

TOPICAL EXAMINATIONS.

GASEOUS EXCHANGE AND RESPIRATIONS.

NAME………………………………………..CLASS………………………………………….………..……TIME: 2¹/₂HRS

INSTRUCTIONS:-

1. This paper consists of sections A, B and C

2. Answer all questions

3. All answers must be written in the spaces provided

4. All writings should be in blue/black inks except for drawings that should be in pencils

SECTION A.

1. MULTIPLE CHOICE QUESTIONS.

i) Oxygen passing from the atmosphere into the blood of a mammal takes one of the following routes. Which one?

A. Trachea - bronchi – bronchioles-alveoli

B. Trachea - bronchioles – bronchi-Alveoli

C. Bronchi - bronchioles – trachea-Alveooli

D. Bronchioles - bronchi – trachea-Alveoli

ii) Which of the following sets contains respiratory gases only?

A, Oxygen and argon

2. Oxygen and carbon dioxide

3. Hydrogen and argon

4. Carbon dioxide and hydrogen

iii) Where does gaseous exchange take place in man?

A. Gills B. Trachea

C. Lungs D. Skin

iv) The lungs are enclosed in double membrane known as

1. plasma lemma

2. plasma membrane

3. lung membrane

4. pleural membrane.

v) The following are characteristics of a respiratory surface, which one is not?

1. Has a large surface area.

2. Has a good network of blood capillaries.

3. Has thick membrane.

4. Has moist surface.

vi) Where does gaseous exchange take place in a plant?

1. Spongy mesophyll cells.

2. Palisade cells.

3. Guard cells.

4. Stomata.

vii) Which of the following statements is not true?

A. During the day plants take in carbon dioxide.

2. During the day plants take in oxygen.

3. At night plants take in oxygen

4. At night plants release carbon dioxide.

viii) Terrestrial plants obtain respiratory gases from

1. the surrounding water

2. the atmosphere

3. A and B

4. none of the above.

ix) The compound in which oxygen is transported is referred to as

1. oxyhaemoglobin

2. carboxyhaemoglobin

3. haemoglobin

4. haemorrhage.

x) One of the following is not a respiratory surface

A. skin B. nostrils

C. gills D. mouth cavity.

2. Matching items question.

List A

LIST B

Gaseous exchange structure of amoeba. Gaseous exchange structure of spider Diffusion of gases in and outside the respiratory surface. Found in chest cavity and filled with fluid which reduces friction The form in which oxygen is carried in blood. Areas with loosely packed cells which allows for gaseous exchange. The inner membrane of a mitochondrion The product of anaerobic respiration in animals The least energy required by the body at rest. A type of respiration which occurs in the cytoplasm.

Mitochondrion Cristae Pleural cavity Pleural membrane Cytoplasm Cell membrane Spiracles Book lung Respiratory quotient Basal metabolic rate Lenticels Cork cells Matrix Anaerobic respiration Lactic acid Ethanol Oxyhaemoglobin carboxyhaemoglobin

SECTION B.

3. (a) Name the structures used for gaseous exchange in the following organisms:

1. Fish

2. Mammal

3. Bird

4. Grasshopper

5. Land ( terrestrial) green plants

6. Spider

7. Tadpole

8. Frog

9. Amoeba

2. Explain why it is not possible to drown or suffocate a locust or grasshopper by holding its head under water while the remaining part of the body is outside the water.

2. (a) Explain why a fish suffocates on dry land although atmospheric air contains more oxygen than water.

2. Give reasons why it is healthier to breathe through the nose than through the mouth.

2. (a) State the composition of inspired air and expired air in man.

(b) What is the role of the diaphragm during inspiration and expiration.

6. Explain why

1. It is not healthy to sleep in a closed room with potted plants

2. It is dangerous to sleep in a poorly ventilated room with a charcoal burner on

3. One pants during heavy exercises.

7. Explain why;

i) The rate of breathing increases rapidly during exercise

ii) Your breathing rate does not go back to normal as soon as you stop exercising.

8. i) (a) Why is it better to breathe through the nose and not the mouth?

b) Explain what will happen if epiglottis is removed from the body

ii) Briefly explain how breathing takes place in humans.

9. Differentiate between glycolysis and krebs cycle

10. Briefly give the differences between respiration and photosynthesis

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CHAPTER 7

TRANSPORT IN PLANTS

KEY TERMS AND CONCEPTS.

• Vascular bundles- these includes xylem and phloem which are responsible for conduction of water and food.

• Cambium- this is a layer found between xylem and phloem and is responsible for secondary growth.

• Lign- a substance found in xylem and helps in strengthening it.

• Tracheid elements- are elongated cells with tapering ends for water conduction.

• Sieve plates- They have perforations or pores

• Companion cells- have high concentration of mitochondrion which provides energy for active transport.

• Translocation- this is the movement of food substance within plant body.

• Transpiration- this is the loss of water in form of water vapour from the plants

• Transpiration stream- this is continuous movement of water from roots to the leaves as a result of transpiration pull.

• Transpiration pull- this is a hidden force which pushes water up the plant from roots.

• Cohesion force- this is the force of attraction between like molecules

• Adhesion force- this is the force of attraction between different molecules

The transport system in plants is not as complex as that of animals. Materials are transported by vascular bundles made up of xylem and phloem tissues. Xylem tissue transports water and mineral salts from the soil to all parts of the plant. Phloem tissue transports manufactured food from the sites of photosynthesis to all parts of the plant. In between the xylem and phloem is cambium. The cambium divides to form new xylem and phloem.

Xylem

• Xylem tissue is made up of the xylem vessels and the tracheids.

• Mature xylem vessels and tracheids are made up of hollow and dead cells.

• Their walls are made of cellulose and lignin. Lignin strengthens the cell walls and makes them rigid.

• Therefore, xylem has an additional function of giving support to the plant.

The movement of substances in the xylem is always upward and is by conduction.

A xylem vessel is made of hollow cells without end walls. These cells are joined end to end to form a pipe-like structure.

• Xylem vessels begin in the roots, go up through the stem and branch into every leaf of the plant.

• Xylem vessels have no cytoplasm and nuclei. This enables them to transport a larger volume of water and mineral salts.

Tracheid elements are elongated with pointed (tapering) ends.

• They are also laid end to end to enable continuous flow of water.

• Their end walls have perforations (pits) unlike in xylem where end walls are missing.

• This makes them less efficient in conduction of water.

Phloem

The phloem tissue is made up of sieve-tube elements and companion cells.

• Like xylem vessels, sieve-tube elements are made of cells that are joined end to end.

• However, the end walls of these cells are not completely broken down.

• They have perforations or pores that form sieve plates. These cells contain cytoplasm but they have no nucleus. Fibres run through the pores thereby connecting adjacent sieve-tube cells.

Each sieve-tube element has a companion cell. They are separated by a thin wall made up of parenchyma cells with pores called plasmodesmata which allow exchange of materials between them.

Figure 7.1 Vascular Bundles

Companion cells have a high concentration of mitochondria. They provide the sieve-tube elements with energy.

The movement of substances in the phloem is by translocation. It can be in any direction.

The distribution of vascular bundles in plants.

The way the vascular bundles are arranged in the roots, stems and leaves of monocots and dicots differ. This arrangement also differs in the roots and stems of the two categories of plants.

Monocotyledonous root

The arrangement of vascular bundles is as shown

Dicotyledonous root

The xylem is centrally positioned and star-shaped. The phloem is found between the extensions of the xylem as shown below

Figure 7.2 vascular bundles in dicot and monocot roots

Monocotyledon stem

The arrangement of vascular bundles is random.

Figure 7.3 vascular bundles in dicot and monocot stems

Absorption and movement of water and mineral salts

Plants absorb water and mineral salts from the soil through root hairs.

Structure and functions of root hairs

Root hairs are extensions of the epidermal cells of the root.

• Root hairs are long and slender to provide a large surface area for the absorption of water and mineral salts from the soil.

• The large number of root hairs also increases the total surface area of the roots.

• Transpiration occurs when water evaporates from the plant through the stomata in the leaves.

• As the water is lost, the mesophyll cells draw water from the xylem in the leaf which in turn draws water from the xylem in the stem.

• This creates a tension called transpirational pull which draws water from the roots.

This results in a continuous column of water from the roots, through the xylem to the leaves. This column of water is called transpirational stream.

Figure 7.4 Transpiration stream.

• The root hair cell sap is usually hypertonic to the surrounding. Hence, water enters the cell by osmosis.

• Root hair cells have a higher concentration of minerals than the surrounding. Mineral salts are therefore absorbed by active transport.

• The root hairs are very thin in order to provide a short distance over which absorption of water and mineral salts takes place.

Movement of water and dissolved mineral salts

• When water is absorbed by the root hair, it dilutes the contents of the cell sap vacuole.

• As a result, the cells of the cortex, which are adjacent to the epidermis, have less water than the root hair cells.

• Water moves from the root hair cells to the cortex cells by osmosis. It moves the same way into the cells of the endodermis, then into the pericycle and then into the xylem.

Capillarity

• Capillarity is the action that causes water to rise in narrow tubes. Xylem vessels have a narrow lumen which makes it possible for water to rise in the by capillarity.

• Capillarity is made possible by cohesion and adhesion forces. Cohesion is the attraction between like molecules.

• It makes the water molecules stick to each other. Adhesion is attraction different molecules. It causes water molecules adhere to the xylem vessels.

Figure 7.5 Capillarity.

Root pressure

• Root pressure pushes water and dissolved mineral salts upwards from the root.

• This happens because the cells of the endodermis push mineral salts into the xylem.

• This increases osmotic pressure in the xylem thereby creating a force that moves the water and dissolved minerals up the xylem vessel.

• When a plant is cut, fluid oozes out of the remaining stem (stump). This is proof of root pressure in plants.

Figure 7.6 Root pressure.

• Transpiration is the process by which plants lose water through the stomata in the leaves.

• Water flows from the roots to the leaves through the xylem vessels. It enters the spongy mesophyll by osmosis.

• The spongy mesophyll has substomatal air spaces where water enters as water vapour.

• As a result, the concentration of water vapour in the substomatal air spaces becomes higher than the concentration of water vapour in the air. This causes water to diffuse into the atmosphere through the stomata.

• Another process known as guttation also occurs in plants. It is the process by which plants lose water as droplets through special glands found where veins are in contact with the leaf margin.

• Guttation is different from transpiration in that transpiration is the loss of water vapour mainly through the plants stomata. Guttation occurs mostly at night or in plants growing in wet areas.

Figure 7.7 Gutation

Types of transpiration

There are three types of transpiration:

1. Stomatal- This transpiration occurs through the stomata on the leaves. It accounts for approximately 90% of the water lost by plants.

2. Cuticular- A type of transpiration that happens through the cuticle of leaves. The cuticle is a waxy layer that covers the surface of leaves. A thick cuticle prevents excessive loss of water.

3. Lenticular transpiration takes place through the lenticels. Lenticels are pores found on the bark of stems or roots in woody plants.

Factors affecting the rate of transpiration.
The rate of transpiration is affected by plant features as well as environmental factors.

Plant features

Plant features include the following:

The size of leaves: A large leaf has more stomata than a small leaf. Therefore, plants with large leaves lose more water than those with smaller leaves.

An extensive root system: Plants that have extensive roots absorb more water and can therefore lose more water than those with few roots.

Leaf cuticle: A thick cuticle resists water loss by transpiration while a thin cuticle makes water loss by transpiration easier.

Number of stomata: The more stomata a leaf have, the faster the rate of transpiration and vice versa.

Position of stomata: Stomata on the upper surface of the leaf lose water more easily than those on the lower surface. If a plant has leaves with more stomata on the upper surface, the rate of transpiration is faster than in a plant that has leaves with more stomata on the lower leaf surface.

Size of substomatal air spaces: Larger air spaces allow for a faster rate of transpiration because the leaves can hold more water vapor. Smaller substomatal air spaces slow down the rate of transpiration.

Sunken stomata: Sunken stomata occur in pits. They are not exposed to moving air so they slow down transpiration rate.

Epidermal hairs: Epidermal hairs trap water on the surface of the leaves, thus preventing water loss.

Environmental factors

Temperature: Transpiration rates go up as the temperature goes up. Higher temperatures cause the stomata to open and release water into the atmosphere. Lower temperatures cause the stomata to close.

Relative humidity: As the relative humidity of the surrounding air rises, the transpiration rate falls. It is easier for water to evaporate into dry air than into air saturated with moisture.

Wind and air movement: Increased movement of the air around a plant results in a higher transpiration rate. As water transpires from a leaf, the water saturates the air surrounding the leaf. If there is no wind, the air does not move, thus raising the humidity of the air around the leaf. Wind moves the air causing diffusion gradient the more saturated air close to the leaf to be replaced by drier air.

Availability of soil moisture: When moisture is lacking in the soil, plants begin to senesce (age prematurely) resulting in leaf loss and reduced transpiration. Also, less water is absorbed by the roots when the soil is dry.

Light: Increased sunlight increases the rate of photosynthesis in the guard cells, causing them to become turgid and open the stomata. Higher light intensity also increases the plants internal temperature and hence increases the rate of transpiration.

Atmospheric pressure: When atmospheric pressure is low, for example at high altitudes, plants lose water more easily. The rate of transpiration is reduced in areas with high atmospheric pressure.

Significance of transpiration

1. It helps to maintain transpiration pull which is important for maintaining a constant stream of water between the roots and the leaves.

2. Transpiration enables the loss of excess water from the plant.

3. It helps to cool the plant and enables absorption and distribution of water and mineral salts.

SUMMARY.

1. The vascular system in plants is made up of xylem and phloem tissues.

2. Xylem transports water and minerals salts from the roots to all parts of the plant.

3. Phloem transports manufactured food from the site of photosynthesis to all parts of the plant.

4. The distribution of vascular bundles is different in roots and stems and in dicotyledonous and monocotyledonous plant.

5. Root hair are extensions of the epidermal cells of the root. They absorb water and minerals salts from the soil.

6. Water is absorbed from the soil by osmsosis.

7. Minerals salts are absorbed from the soil by active transport.

8. Water and dissolved minerals move up the xylem by transpiration pull, capillary and root pressure .

9. Transpiration is the process by which plants lose excess water through their leaves.

Transpiration is important because it:

• Helps to maintain the transpirational stream

• Enables the loss of excess water

• Enables absorption and distribution of water and minerals salts in a plant.

• Helps to cool the plant.

10. Transpiration is affected by the features of the plant and environmental factors. The features of the plant include: leaf size, size of root system, size of the leaf cuticle, Size of air spaces, number and position of stomata and whether the stomata are sunken or not, and the presence of epidermal hairs.

11. Environmental factors include the amounts of moisture in the air, temperature, air movement, availability of soil moisture, light and atmospheric pressure.

TRANSPORT OF MATERIALS IN PLANTS QUESTIONS

1. Choose the correct answer from the alternatives given.

1. Water and mineral salts in plants are transported through__________

1. Xylem

2. Phloem

3. Cambium

4. Epidermis

2. Which of the following forces does not facilitate upward movement of water?

1. Capillarity

2. Root of pressure

3. Mass flow

4. Transpiration

3. Before transpiration through stomata in leaves water vapour os stored in the ____________

1. Cuticle

2. Guard cells

3. Spongy mesophyll

4. Guard cells

5. Spongy mesophll

4. When the environment is too cold, plants lose water through________

1. Hydathodes

2. Cuticle

3. Stomata

4. Guard cell

5. Which the following decrease the rate of transport?

1. Numerous stomata

2. High wind

3. High temperature

4. High humidity

2. Write True for the correct statements and False for the wrong statement.

1. The other name of the transport system in plants is known as vascular system.

2. Xylem is made up of xylem vessels and sieve tubes.

3. Movement of substances through tracheas is more efficient than through xylem vessels.

4. Active transport goes against concentration gradient.

5. Minerals salts are less concentrated in the roof of a plant than in the soil.

3. (a) Differentiate between transpiration and guttation

__________________________________________________________________________________________________________________________________________________________________________________________________________________________________________

(b) Explain why transpiration is the necessary evil? (3points in each case)

________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________

4. Fill the blanks

1. __________ are elongated cells that have end walls performed by numerous minute holes in plants.

2. The end of walls of tracheids have holes called___________.

3. __________- is the force of attraction between similar molecules.

4. __________ is the force of attraction between different molecules.

5. The process which involves loss of water into the atmosphere through stomata in plants is known as________.

5. What do you understand by the following terms?

1. Transpiration

2. Root pressure

3. capillary

4. vascular system

6. What is the vascular system?

7. Briefly describe the components of the vascular system.

8. Explain the function of each component of the vascular system.

9. Write short notes on how water moves from the roots up to the leaves. Elaborate on the role of the forces involved.

10. without roots, no transportation. Explain this statement.

11. What is transpiration?

12. Explain why transportation has to take place in plants.

13. List down any four factors which affect the rate of transpiration in plants.

QUESTION AND ANSWER SECTION.

Q. i) Give the importance of transport in living organism.

2. Explain why amoeba does not need an elaborate transport system.

3. Define Diffusion, osmosis and mass flow.

iv)What factors affect rate of diffusion?

A. Transport is movement of material from one part of body of organism to another.

Importance.

• Distribute food in body.

• Help to eliminate waste products.

• Assists in distribution of chemicals such as hormones.

2. Amoeba does not need an elaborate transport system because exchange of material occurs on its membrane, as it has a large surface area.

3. Osmosis is the movement of solvent molecule from region of high concentration to region of low concentration through a semi — permeable membrane.

• Diffusion is movement of molecules from a region of high concentration to region of low concentration

• Mass flow is movement of fluid in vessels; Within the body of organism.

i) Factors affecting diffusion rate include.

• Diffusion gradient.

• Size of molecules.

• Thinness of membrane.

• Temperature.

Q. Mention process in living organism that depends on diffusion.

A. These include.

1. Gaseous exchange

2. Absorption of food

3. Excretion of water.

Q. a) What do you understand by.

1. Hypertonic solution.

2. Hypotonic solution.

3. Isotonic solution.

b) In relation to above, explain what will happen when a plant cell and animal cells are placed in hypotonic solution.

3. Define these terms i) Turgor pressure ii) wall pressure iii) Osmotic potential.

4. Explain the following terms relating to cell is various solutions.

1. Plasmolysis ii) Haemolysis iii) turgidity. Iv) Crenation v) Flaccid.

A. a) i) Hypertonic solution: This is a solution with high concentration of solute molecule than surrounding region.

2. Hypotonic — Is a lowly concentrated solution compared to surrounding region.

3. Isotonic solution — Is a solution with same concentration as surrounding region.

4. b) i) Plant cell when placed in hypotonic solution will gain water, bulge out and become Turgid

An animal cell when place in hypotonic solution will gain water and burst through Haemolysis.

Plant cell do not burst because they have a tough cell wall.

c) i) Turgor- pressure — This is out ward pressure excreted by water within the cell.

2. Wall pressure — Is hidden pressure that opposes turgor pressure. It is generated by cell wall.

3. Osmotic potential — This is the tendency of a cell to draw in water.

d) i) Plasmolysis — This is when a plant cell loose water and shrinks.

ii) Haemolysis — This is the bursting of red blood cells when placed in hypotonic solution.

Q. A. student set — up the apparatus below to investigate osmosis.

1. What will happen after sometimes.

2. What does visking tubing represent in a living cell?

3. Name two process that depend on above process.

A. i) After sometimes, the visking tubing will swell and bulge outward due to water intake.

Q.

ii) visking tubing represents a cell membrane
➢ Reabsorption of water is kidney.

➢ Absorption of water and mineral salt

A student set —up the experiment below to show osmosis in living tissues

A. i) Water moved from the beaker into scooped potato through osmosis. In the beaker we have high concentrations of solvent molecule than is sugar solution.

2. If the potato was boiled, water could not have moved to scooped part because permeability could have being killed.

3. The live potato acts are semi-permeable membrane.

Q. Explain why amoeba, paramecium can survive in flesh water yet they do not burst.

A. They have contractile vacuole which helps to remove excess water.

1. Turgidly — A Term used to describe a cell that have taken in water and is bulging

outward.

2. Crenation — is shrinking of an animal cell when placed in hypertonic solution.

3. Flaccid — Is a plant cell placed in hypertonic solution in which cell membrane has drawn inwards.

Q. a) What is the effect of HIV on white blood cells.

b) Explain why a person with blood group B cannot donate blood to person with blood group A.

c) What is agglutination

d) What is antigen, antibody? e) Which blood group is called?

1. Universal donor.

2. Universal recipient.

1) Give a reason why blood group 0 can give blood to any blood group.

i) Give conditions that can lead to blood transfusion

ii) What precautions needs to be taken before blood transfusion.

7. What is rhesus factor?

8. What will happen if rhesus +ve mother give birth to rhesus -ve positive child?

In 1628, English doctor William Harvey published full account of how blood circulates around the body.

A. A) HIV Virus attack and make copies of new HIV from existing white blood cells. This decrease the amount of white blood cells thus lowering body immunity.

2. A person with blood group B cannot denote blood to a person with blood group A Because, Blood group B contain antigen b and antibody a while blood group A has antigen a and

Antibody b . When antigen b meet antigen b agglutination occurs.

2. Agglutination is clamping together of blood when corresponding antigen and antibody

meet.

2. Antigen is a protein found on surface of red blood cells they determine blood groups

Antibody is protein found on blood plasma. It can also be manufactured by lymphocytes.

Blood group 0= universal donor Blood group AB universal receipt

2. Blood group 0 can give blood to any blood group because it contains none of antigen, therefore no likelihood of agglutination occurring.

3. i) conditions that can necessitate blood transfusion are;

- Loss of Blood after an accident

- Prolonged sickness, leading to low blood level

- Anaemia

- Loss of blood during operation or during birth

ii) Precautions to be taken during blood transfusion?

• Screen blood to check if it has other diseases e.g malaria, HIV

• The age of donor should be above sixteen years and below 60.

• Blood should be taken from vein and not artery

• The donor should be healthy

• Blood group of donor should be compatible with that of the recipient.

h) Rhesus factor is an extra antigen found on blood cells of some individual it is also called antigen "D"

I) If Rhesus +ve mother gives births to rhesus -Ve Child antigens will cross from mother to child, causing production of antibodies. The first pregnancy there wont be enough antibodies and the child will survive. However in subsequent pregnancies the child dies because antibodies are many leading to severe agglutination.

a) i) Mention components of blood.

ii) Give the function of blood.

iii) Which blood component is concerned with?

• Defending the body from diseases.

• Preventing excessive bleeding after injury

• Transport of oxygen.

Differentiate between Granulocytes and lymphocytes

4. Give adaptations of erythrocytes to their functions

What is plasma, give functions blood plasma b) Where are the following blood cells manufactured?

i) Erythrocytes (ii) Leucocytes.

A. i) Blood consists of, white blood cells, red blood cells platelets, plasma hormones dissolved gases, urea,mineral salts.

ii) Functions blood.

• Transport of oxygen from lungs to tissues

• Transport of carbon dioxide from tissue to lungs.

• Transport of digested food from intestines to tissue.

• Transport nitrogenous wastes from liver to kidney.

• Transport of hormones from gland to effectors

3. White blood cell.

4. Platelets

1. Red blood cells. Granulocytes have ability to change shape, thus easily engulf pathogens

2. Adaptations of erythrocytes

• Lack nucleus to create space for haemoglobin

• Contain hemoglobin which carry oxygen

• Have no shape so that they can squeeze between capillaries

• Have biconcave shape to carry oxygen.

a) Plasma is the liquid part of blood yellow in color

Plasma plays the following roles;

• Transport carbon dioxide in form of carbonic acid

• Transport food and hormones

• Regulate body temperature

b) Erythrocytes are made in spleen and bone marrow of long bone

Leucocytes are made in bone marrow of short bones

Q. a) Differentiate between the following terms

Double and single circulation

Systemic and Pulmonary circulation

What is blood pressure?

3. How do capillaries differ from other blood vessels in their structure and function

4. Describe the path taken by a molecule of glucose from the time it is absorbed in small intestines, and path taken by molecule of oxygen absorbed in lungs to the time when they both meet in a muscle cell of the leg.

A a) Double Circulation occur when blood passes through heart twice to complete one circulatory cycle.

• Single circulation is when blood passes through heart once to complete on circulatory cycle - Systemic Circulation this is heart — lung — body heart circulation, blood passes through the heart twice.

• Pulmonary circulation — is when blood moves from heart to lungs to back to heart.

Blood pressure is the pressure exerted at the arteries during contraction and relaxation. It is measured in beats per minute.

Capillaries have one cell thick wall for diffusion of substances. Their function is to aid in exchange of substances.

d) Glucose molecule moves from intestines into liver through hepatic portal vein, from liver it goes to venacava through hepatic vein then to right auricle, right pulmonary artery the lungs, pulmonary artery to left atria, left ventricle to aorta, to arteries to body muscles. Molecule of oxygen from lung goes to pulmonary vein, and then to left atrium, left ventricle, aorta, to arteries and to muscles.

Human body contains about 100,000km of blood vessels. Arteries take blood away from the heart while veins take blood to the heart.

Q (a) Give the following.

• A blood vessels that collect blood from lower parts of the body

• Valves that control flow of blood left ventricles and left auricle.

• Valves found at the base of pulmonary artery

• Valves found between right auricle and right ventricle

• Artery which supplies blood to interstices.

• The vein that carry blood from wall of heart.

(b) Give the adaptation of the heart.

A

• Inferior vena cava

• Bicuspid valve

• Semi- lunar valves Tricuspid valve

• Carotid artery Coronary vein

(b) Adaptation of heart.

• Its wall is made of muscle called cardiac, which do not fatigue

• It is supplied by blood vessels called coronary arteries/veins

• Have valves which control flow of blood

• Have tendons which help to open and close the heart chambers.

• Left ventricle is muscular to pump to all parts of the body.

Q (a) Give a reason for the following;

• Blood capillaries are made of single — celled porous wall.

• Blood vessels have smooth endothelium

• Arteries have more muscular wall than veins

• The lumen of arteries is smoother than that of veins.

• Left ventricle is muscular than right ventricle.

• Veins have valves while arteries do not.

• Blood in arteries flow in pulses while in veins it flows smoothly.

(b) Give factors that aid in movement of blood in veins.

c) The diagram represents structure of heart

1. Name parts A to K)

2. Which Which blood vessels carry blood rich in oxygen?

3. Explain differences in thickness of chamber I and K

4. Which part pumps blood to arteries?

5. Put the followings in correct order; (a) blood enters arteries (b) Ventricles contract (c) atria contract (d) Ventricle relax (e) blood enters ventricles (f) Semi lunar valves close. (g) Tri- and Bicuspid valves close. (d) Why is a person whose heart valves are damaged by disease unable to take part in active sport?

A (a) — This is to enable diffusion of substance such as food and gases to take place.

Smooth endothelium help to reduce friction as blood passes through artery.

Artery has muscular wall than veins to withstand pressure generated from the heart.

• Arteries have small lumen so as to prevent them from bursting and also maintain pressure.

• Left ventricle is muscular than right ventricle because it pumps blood to furthest parts of the body.

• Veins have valves because blood flow with low pressure to prevent it from going backward. Because blood flow with high pressure in arteries, it creates pulses.

b) Factors that assist in movement of blood in veins

- Presence of valves which prevent back flow of blood.

- Muscular contractions which squeezes blood.

c) i) Parts A - Bicuspid valve B. Pulmonary vein C. Left auricle D vena cava E. Aorta F. left ventricle G Eventide H. septum I. wall of left ventricle J. Semi-lunar valves.

2. Part B

3. Chamber I carry blood to all body parts, hence it is thicker than chamber k which carry blood to lungs.

4. Part F pumps blood to arteries.

v) Atria contract, ventricle relax Blood enters ventricle, Tri — and Bicuspid valves close, ventricle contract blood enters arteries, semi-lunar valves close.

d) Person whose heart valves are damaged is unable to take part in active sports because blood takes long to go to heart and then to lungs for oxygenation

Q. a) Mention the ailments of circulatory stem?

b) Explain how lymph is formed?

c) i) Name blood vessels that takes lymph back to blood stream

2. How does lymph flow in lymph vessels?

3. Give the constituent of lymph fluid

d) Give function of lymphatic system.

e) Mention disorders of lymphatic system.

f) explain the mechanism of blood clotting.

A a) Disorders of circulatory system

- Hypertension - Sickle- cell anemia

- leukemia - Diabetes

b) Lymph is formed through filtration at end of capillaries Blood pressure in capillaries cause some materials to come out of blood with water and enter tissue space forming lymph.

c) i) Subclavian vein

2. Contraction of skeletal muscles squeezes lymph in lymph vessels aiding in movement

3. Lymph consists of water dissolved food substances, salt,wastes, hormones among others.

d) Function of lymph

- Transport of substance

- Defend of body from diseases (lymphocyte)

- Regulation of temperature.

e) Disorder of lymphatic system

Oedema - swelling

Elephantiasis
Hypertension

f). When a blood vessel is injured, thromboplastin, coverts prothrombin to thrombi. Thrombin, converts fibrinogen to fibrin. Fibrin forms a meshwork of fibres which prevents further loss of blood. Thromboplastin also neutralizes heparin which normally prevents blood from clotting while in the vessels.

Q The diagram below certain structure of plant parts A and B