MITIHANI POPOTE EXAMINATIONS SERIES
FORM FOUR BIOLOGY EXAMINATION SERIES 4
SECTION A (16 Marks)
Answer all questions in this section
1. For each of the items (i) – (x), choose the correct answer from among the given alternatives and write its letter beside the item number in answer booklet(s) provided.
- Suppose you have been assigned by your School Head to cross-section cutting down the mango stem and then recommend on the arrangement of vascular bundle. Which one would you recommend?
Answer: C. Ring pattern
Explanation: In dicotyledonous plants like mango, vascular bundles are arranged in a ring pattern in the stem, with xylem and phloem organized in a circular manner. - Mr. Chisambi wants to export glass materials from Tanzania to Zambia but he fears on its safety of his luggage. Recommend the biological term that he could put on item’s box as a safety sign.
Answer: A. Fragile
Explanation: "Fragile" is the appropriate term to indicate that the glass materials need careful handling, though it is not strictly a biological term. - Spider man Camara has a farm around Indian ocean, he planted a bean seeds but didn’t grow to maturity because all died after some weeks later. The process stopped due to
Answer: A. Plasmolysis
Explanation: The salty water from the Indian Ocean likely caused plasmolysis, where water leaves plant cells due to high external salt concentration, leading to wilting and death. - Form four students at Markaz Islamic Seminary were given a scalpel and hibiscus flower and they were required to dissect and display the female reproductive parts. Which parts expected to be displayed?
Answer: A. Ovary, style and stigma
Explanation: The female reproductive parts of a flower (pistil) include the ovary, style, and stigma. - ______________are considered to be very successful group of animals on earth due to their diversity in life style, feeding methods and even movement.
Answer: D. Insects
Explanation: Insects are highly diverse in lifestyle, feeding, and movement, making them one of the most successful animal groups. - Two people were cutting firewood in the forest then they saw a Buffalo and suddenly climbed a tree to escape the Buffalo. That action was facilitated by
Answer: B. Adrenaline hormone
Explanation: Adrenaline triggers the "fight or flight" response, increasing heart rate and energy for quick actions like climbing a tree. - Being a footballer Bullbazz is likely seen to lose a lot of water through sweating. As upcoming doctor, identify the organ of the body which is responsible for the loss?
Answer: B. Skin
Explanation: The skin is responsible for water loss through sweating via sweat glands. - Doctor Janabi emphasized women to breastfeed their babies to strengthen their body immunity. The aim of Doctor Janabi’s advice is to help babies to acquire:
Answer: A. Natural passive immunity
Explanation: Breast milk provides antibodies, conferring natural passive immunity to babies. - Muzine took a thermometer and measured temperature of the following organisms frog, duck, rat, lizard and rabbit under cold condition environment and later on under hot condition environment, the temperature didn’t to some organisms like
Answer: D. Rabbit, duck and rat
Explanation: Rabbit, duck, and rat are endothermic (warm-blooded) and maintain constant body temperature, unlike ectothermic frog and lizard. - The child of Burhan has protruding stomach and swollen limbs, to overcome the problem Burhan should provide his child food rich in
Answer: E. Protein
Explanation: Symptoms suggest kwashiorkor, a protein deficiency disease, so a protein-rich diet is needed.
2. Match the descriptions in Reproduction in LIST A with the correct response in LIST B by writing the letter of the correct response beside the item number.
| List A | List B | Answer |
|---|---|---|
| Giving death to a dead baby due to poisons, chemical or shock. | I. Still birth | I |
| Giving birth after six months and a baby put in an incubator. | B. Pre mature birth | B |
| Condition when fertilized ovum fail to move to the uterus. | H. Ectopic pregnancy | H |
| A baby born bottom first instead of head first. | G. Breech birth | G |
| Condition of pregnancy characterized by high blood pressure and protein in the urine. | F. Preeclampsia | F |
| Termination of a pregnancy before fully developed. | E. Miscarriage | E |
SECTION B (54 Marks)
Answer all questions in this section
3. After a heavy rain season, a house of Madam Bibi was surrounded with stagnant water with green scum.
- Identify the microorganisms that cause green scum on water.
Answer: The microorganisms causing green scum are algae, specifically green algae (e.g., Spirogyra or Chlorella). - Draw a well labelled diagram of microorganism identified in 3(a) above and label the parts with the following functions:
(i) Movement (locomotion)
(ii) Regulate water content
(iii) Photosynthesis process
Note: A diagram of a green alga (e.g., Spirogyra) would show:
- Flagella (for movement, in some algae like Chlamydomonas).
- Contractile vacuole (for regulating water content, in some unicellular algae).
- Chloroplast (for photosynthesis).
[Diagram description: A filament of Spirogyra with cylindrical cells, each containing spiral chloroplasts, a nucleus, and a cell wall. For unicellular algae like Chlamydomonas, include flagella and contractile vacuole.]
4. (a) Explain each of the following biological phenomena.
- A plant with yellowish leaves produce poor yield than a plant with green leaves.
Answer: Yellowish leaves indicate chlorosis, often due to a lack of chlorophyll caused by nutrient deficiencies (e.g., nitrogen, magnesium). Chlorophyll is essential for photosynthesis, so reduced chlorophyll leads to less glucose production, resulting in poor growth and yield. - A fish can live in water where there is low amount of oxygen gas but it tends to die when placed on a land where there is higher amount oxygen gas.
Answer: Fish extract dissolved oxygen from water via gills, which are adapted for aquatic environments. On land, gills collapse and cannot extract atmospheric oxygen efficiently, leading to suffocation despite higher oxygen availability. - Growth is quantitative while development is qualitative.
Answer: Growth refers to measurable increases in size, weight, or cell number (quantitative). Development involves changes in structure, function, or complexity (qualitative), such as differentiation of cells or organs.
(b) Transpiration is said to be necessary evil, explain by giving three (3) points.
- Transpiration drives the uptake of water and nutrients from roots to leaves via the xylem, essential for plant growth.
- It helps regulate leaf temperature by evaporative cooling, preventing overheating.
- However, excessive water loss through transpiration can lead to wilting or dehydration, especially in dry conditions, making it a "necessary evil."
5. (a) How does irresponsible sexual behaviour differ from responsible sexual behaviour?
Irresponsible sexual behavior includes unprotected sex, multiple partners, or engaging in sexual activities without consent, leading to risks like STIs, unplanned pregnancies, or emotional harm. Responsible sexual behavior involves consensual, protected sex, mutual respect, and awareness of health and emotional consequences.
(b) Briefly explain four ways which can be used to eradicate irresponsible sexual behaviour.
- Education and awareness: Provide comprehensive sex education to promote safe practices and consequences of risky behavior.
- Access to contraceptives: Ensure availability of condoms and other contraceptives to reduce unprotected sex.
- Counseling and support: Offer guidance to encourage healthy relationships and decision-making.
- Community campaigns: Promote cultural and social norms that value responsible sexual behavior.
6. (a) In Biology Binomial Nomenclature used to assign organisms the scientific names. Outlines four rules used to recognize organisms internationally.
- The scientific name consists of two parts: genus (capitalized) and species (lowercase).
- Names are written in italics or underlined when handwritten.
- Names are universally accepted in Latin to ensure consistency across languages.
- The genus name can be abbreviated to its first letter after the first mention (e.g., H. sapiens).
(b) Outline five (5) significances of Mitosis.
- Facilitates growth by increasing cell number in multicellular organisms.
- Enables tissue repair and replacement of damaged cells.
- Maintains genetic stability by producing identical daughter cells.
- Supports asexual reproduction in some organisms (e.g., binary fission).
- Ensures equal distribution of chromosomes to daughter cells.
7. When doing experiment, accidentally Jokha touched the hot water with her finger and she immediately withdrew it.
- Explain the process of impulse flow touching hot water to the moment she responded. Give five (5) points.
- Heat receptors (thermoreceptors) in the skin detect the hot water stimulus.
- Sensory neurons generate nerve impulses and transmit them to the spinal cord.
- In the spinal cord, interneurons process the signal in a reflex arc.
- Motor neurons carry the impulse to the muscles in the arm.
- Muscles contract, causing Jokha to withdraw her finger rapidly.
- Draw the sensory neurone that picked up the nerve impulses from the receptor when she touched the hot water and label any four parts.
Note: A sensory neuron diagram would show:
- Dendrites (receive stimulus from receptors).
- Cell body (contains nucleus).
- Axon (transmits impulses).
- Myelin sheath (insulates axon for faster transmission).
[Diagram description: A neuron with dendrites at one end, a cell body with nucleus, a long axon covered by myelin sheath, and axon terminals.]
8. (a) Give three (3) factors that aid ultrafiltration in glomerulus.
- High blood pressure in the glomerulus due to the afferent arteriole’s larger diameter.
- Porous capillary walls (fenestrations) allowing small molecules to pass through.
- Podocytes in Bowman’s capsule with filtration slits enhancing filtration.
(b) Give explanation of each of the following.
- During cold days one produce large quantity of dilute urine.
Answer: On cold days, less sweat is produced, so more water is retained. The kidneys excrete excess water, producing large amounts of dilute urine due to reduced antidiuretic hormone (ADH) secretion. - Urine of normal person does not have glucose.
Answer: In healthy individuals, glucose is completely reabsorbed in the proximal convoluted tubule of the nephron, so it does not appear in urine. - Plasma protein are absent in glomerular filtrate.
Answer: Plasma proteins are too large to pass through the glomerular filtration barrier (capillary walls and podocytes), so they remain in the blood.
SECTION C (30 Marks)
Answer two (2) questions in this section
9. The blood circulation is important for survival of human being. In six (6) points justify this statement.
- Transports oxygen from lungs to tissues for cellular respiration.
- Delivers nutrients from the digestive system to cells for energy and growth.
- Removes waste products like carbon dioxide and urea for excretion.
- Distributes hormones to regulate body functions.
- Carries immune cells to fight infections and maintain immunity.
- Regulates body temperature by distributing heat via blood flow.
10. The interaction of biotic and abiotic components of the environment is important for the natural cycles. How would you justify the statement by explaining seven (7) stages involved in circulation of water in the environment?
- Evaporation: Water from oceans, lakes, and rivers turns into vapor due to solar heat, aided by abiotic factors like temperature.
- Transpiration: Plants (biotic) release water vapor from leaves, contributing to atmospheric moisture.
- Condensation: Water vapor cools in the atmosphere (abiotic) and forms clouds.
- Precipitation: Water falls as rain, snow, or hail due to atmospheric conditions (abiotic).
- Infiltration: Water seeps into the soil, used by plants (biotic) and stored in aquifers (abiotic).
- Runoff: Excess water flows over land into rivers, lakes, or oceans, influenced by terrain (abiotic) and vegetation (biotic).
- Groundwater flow: Water moves underground, interacting with soil organisms (biotic) and geological structures (abiotic), re-entering surface water systems.
11. In a man not every mating/sexual intercourse leads to fertilization give six (6) factors which account for this problems.
- Low sperm count or poor sperm motility: Insufficient or immobile sperm reduce the chance of reaching the egg.
- Ovulation issues: If the woman is not ovulating, no egg is available for fertilization.
- Blocked fallopian tubes: Prevents sperm from reaching the egg or the fertilized egg from reaching the uterus.
- Hormonal imbalances: Disrupt ovulation or sperm production, affecting fertilization.
- Timing of intercourse: Missing the fertile window (ovulation period) reduces fertilization chances.
- Immune system factors: Antisperm antibodies in either partner can attack sperm, preventing fertilization.
MITIHANI POPOTE EXAMINATIONS SERIES
FORM FOUR BIOLOGY EXAMINATION SERIES 4
SECTION A (16 Marks)
Answer all questions in this section
1. For each of the items (i) – (x), choose the correct answer from among the given alternatives and write its letter beside the item number in answer booklet(s) provided.
- Suppose you have been assigned by your School Head to cross-section cutting down the mango stem and then recommend on the arrangement of vascular bundle. Which one would you recommend?
A. Random pattern
B. Scattered pattern
C. Ring pattern
D. Peripheral pattern
E. Zigzag pattern
Answer: C - Mr. Chisambi wants to export glass materials from Tanzania to Zambia but he fears on its safety of his luggage. Recommend the biological term that he could put on item’s box as a safety sign.
A. Fragile
B. Biohazard
C. Corrosive
D. Flammable
E. Toxic
Answer: A - Spider man Camara has a farm around Indian ocean, he planted a bean seeds but didn’t grow to maturity because all died after some weeks later. The process stopped due to
A. Plasmolysis
B. Haemolysis
C. Crenation
D. Transpiration
E. Turgidity
Answer: A - Form four students at Markaz Islamic Seminary were given a scalpel and hibiscus flower and they were required to dissect and display the female reproductive parts. Which parts expected to be displayed?
A. Ovary, style and stigma
B. Anther, ovary and stigma
C. Filament, anther and ovary
D. Ovary, stigma and filament
E. Petal, ovary and anther
Answer: A - ______________are considered to be very successful group of animals on earth due to their diversity in life style, feeding methods and even movement.
A. Protoctista
B. Invertebrates
C. Mollusks
D. Insects
E. Arachnida
Answer: D - Two people were cutting firewood in the forest then they saw a Buffalo and suddenly climbed a tree to escape the Buffalo. That action was facilitated by
A. Growth hormone
B. Adrenaline hormone
C. Anti-diuretic hormone
D. Prolactin hormone
E. Aldosterone hormone
Answer: B - Being a footballer Bullbazz is likely seen to lose a lot of water through sweating. As upcoming doctor, identify the organ of the body which is responsible for the loss?
A. Lungs
B. Skin
C. Kidney
D. Heart
E. Liver
Answer: B - Doctor Janabi emphasized women to breastfeed their babies to strengthen their body immunity. The aim of Doctor Janabi’s advice is to help babies to acquire:
A. Natural passive immunity
B. Natural active immunity
C. Artificial passive immunity
D. Artificial active immunity
E. Active passive immunity
Answer: A - Muzine took a thermometer and measured temperature of the following organisms frog, duck, rat, lizard and rabbit under cold condition environment and later on under hot condition environment, the temperature didn’t to some organisms like
A. Frog, rabbit, and duck
B. Lizard, rabbit and duck
C. Rabbit, lizard and rat
D. Rabbit, duck and rat
E. Duck, lizard and frog
Answer: D - The child of Burhan has protruding stomach and swollen limbs, to overcome the problem Burhan should provide his child food rich in
A. Minerals
B. Vitamins
C. Lipids
D. Starch
E. Protein
Answer: E
2. Match the descriptions in Reproduction in LIST A with the correct response in LIST B by writing the letter of the correct response beside the item number.
| List A | List B | Answer |
|---|---|---|
| Giving death to a dead baby due to poisons, chemical or shock. | A. Caesarean birth B. Pre mature birth C. Baby damage D. Abortion E. Miscarriage F. Preeclampsia G. Breech birth H. Ectopic pregnancy I. Still birth |
I |
| Giving birth after six months and a baby put in an incubator. | B | |
| Condition when fertilized ovum fail to move to the uterus. | H | |
| A baby born bottom first instead of head first. | G | |
| Condition of pregnancy characterized by high blood pressure and protein in the urine. | F | |
| Termination of a pregnancy before fully developed. | E |
SECTION B (54 Marks)
Answer all questions in this section
3. After a heavy rain season, a house of Madam Bibi was surrounded with stagnant water with green scum.
- Identify the microorganisms that cause green scum on water.
Answer: Green algae (e.g., Spirogyra or Chlorella). - Draw a well labelled diagram of microorganism identified in 3(a) above and label the parts with the following functions:
(i) Movement (locomotion)
(ii) Regulate water content
(iii) Photosynthesis process
Answer: For Chlamydomonas (a unicellular green alga):
- Flagella: For locomotion.
- Contractile vacuole: Regulates water content.
- Chloroplast: Site of photosynthesis.
[Diagram description: Oval cell with two flagella at one end, a central chloroplast with pyrenoid, two contractile vacuoles, and a nucleus.]
4. (a) Explain each of the following biological phenomena.
- A plant with yellowish leaves produce poor yield than a plant with green leaves.
Answer: Yellow leaves indicate chlorosis due to chlorophyll deficiency (e.g., from lack of nitrogen). Reduced photosynthesis lowers glucose production, leading to poor growth and yield. - A fish can live in water where there is low amount of oxygen gas but it tends to die when placed on a land where there is higher amount oxygen gas.
Answer: Fish use gills to extract dissolved oxygen from water. On land, gills collapse, preventing oxygen uptake from air, causing suffocation. - Growth is quantitative while development is qualitative.
Answer: Growth is a measurable increase in size or cell number (quantitative). Development involves structural and functional changes, like organ formation (qualitative).
(b) Transpiration is said to be necessary evil, explain by giving three (3) points.
- Transpiration facilitates water and nutrient transport from roots to leaves via xylem.
- It cools leaves through evaporative heat loss, preventing overheating.
- Excessive transpiration can cause dehydration and wilting, making it potentially harmful.
5. (a) How does irresponsible sexual behaviour differ from responsible sexual behaviour?
Answer: Irresponsible sexual behavior involves unprotected sex, multiple partners, or non-consensual acts, risking STIs or unplanned pregnancies. Responsible sexual behavior includes consensual, protected sex with awareness of health and emotional impacts.
(b) Briefly explain four ways which can be used to eradicate irresponsible sexual behaviour.
- Sex education: Teach safe practices and risks of irresponsible behavior.
- Contraceptive access: Provide condoms to prevent unprotected sex.
- Counseling: Promote healthy relationships and decision-making.
- Community campaigns: Encourage norms valuing responsible behavior.
6. (a) In Biology Binomial Nomenclature used to assign organisms the scientific names. Outlines four rules used to recognize organisms internationally.
- Scientific name has two parts: genus (capitalized) and species (lowercase).
- Names are italicized or underlined when handwritten.
- Names use Latin for universal acceptance.
- Genus can be abbreviated after first mention (e.g., H. sapiens).
(b) Outline five (5) significances of Mitosis.
- Enables growth by increasing cell number.
- Facilitates repair of damaged tissues.
- Maintains genetic consistency in daughter cells.
- Supports asexual reproduction in some organisms.
- Ensures equal chromosome distribution.
7. When doing experiment, accidentally Jokha touched the hot water with her finger and she immediately withdrew it.
- Explain the process of impulse flow touching hot water to the moment she responded. Give five (5) points.
- Thermoreceptors in skin detect heat stimulus.
- Sensory neurons transmit impulses to spinal cord.
- Interneurons in spinal cord process signal in reflex arc.
- Motor neurons send impulses to arm muscles.
- Muscles contract, withdrawing the finger.
- Draw the sensory neurone that picked up the nerve impulses from the receptor when she touched the hot water and label any four parts.
Answer: [Diagram description: Sensory neuron with dendrites at one end, cell body with nucleus, long axon covered by myelin sheath, and axon terminals. Label: dendrites, cell body, axon, myelin sheath.]
8. (a) Give three (3) factors that aid ultrafiltration in glomerulus.
- High glomerular blood pressure from wider afferent arteriole.
- Fenestrated capillary walls allow small molecule passage.
- Podocytes with filtration slits enhance filtration.
(b) Give explanation of each of the following.
- During cold days one produce large quantity of dilute urine.
Answer: Reduced sweating on cold days increases water retention. Lower ADH levels lead to dilute urine production. - Urine of normal person does not have glucose.
Answer: Glucose is fully reabsorbed in the proximal tubule in healthy individuals. - Plasma protein are absent in glomerular filtrate.
Answer: Large plasma proteins cannot pass through the glomerular filtration slits.
SECTION C (30 Marks)
Answer two (2) questions in this section
9. The blood circulation is important for survival of human being. In six (6) points justify this statement.
- Transports oxygen to tissues for respiration.
- Delivers nutrients to cells for energy.
- Removes waste like carbon dioxide and urea.
- Distributes hormones for body regulation.
- Carries immune cells to fight infections.
- Regulates body temperature via blood flow.
10. The interaction of biotic and abiotic components of the environment is important for the natural cycles. How would you justify the statement by explaining seven (7) stages involved in circulation of water in the environment?
- Evaporation: Solar heat turns water into vapor (abiotic).
- Transpiration: Plants release water vapor (biomedic).
- Condensation: Vapor cools, forming clouds (abiotic).
- Precipitation: Water falls as rain or snow (abiotic).
- Infiltration: Water seeps into soil, used by plants (biotic).
- Runoff: Water flows to rivers/lakes (abiotic, biotic).
- Groundwater flow: Underground water re-enters surface systems.
11. In a man not every mating/sexual intercourse leads to fertilization give six (6) factors which account for this problems.
- Low sperm count or poor motility.
- Ovulation irregularities in female partner.
- Blocked fallopian tubes preventing sperm-egg meeting.
- Hormonal imbalances disrupting ovulation or sperm.
- Mistimed intercourse outside fertile period.
- Antisperm antibodies attacking sperm.
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