Form 4 Biology national exam 2021 with answers
The 2021 Form 4 national exam paper for Form 4 Biology, question by question. Take it timed like the real exam, then see the answer and explanation to every question.
- 36 questions, 100 marks
- 120 minutes
Take this paper
120 minutes, 100 marks. Multiple choice is marked for you; you mark your written answers against the marking points.
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Instructions to candidates
Answer all questions in the ANSWER BOOKLET. Time: 2 hours.
Section A: select the most appropriate choice of the given alternatives (40 Marks)
- 12 marks
The nerves that arise from the brain are known as _____
- A.Spinal cord
- B.Spinal nerve
- C.Cranial nerves
- D.Central nerves
- 22 marks
The nerve system that is controlled by the hypothalamus is said to be:
- A.Voluntary
- B.Sensory
- C.Autonomic
- D.peripheral
- 32 marks
Using the diagram below indicate the part of the neuron that receives information from other neurons
- A.1
- B.2
- C.3
- D.4
- 42 marks
Using the diagram below answer the question that follows. A girl was involved in an accident and the x-ray showed that the part of the brain indicated by the arrow was damaged due to trauma. What effects would this girl most likely
- A.Partial or complete memory loss
- B.Body temperature fluctuation
- C.Trouble in maintaining balance
- D.Rapid breathing
- 52 marks
The primary function of the melanin is to:
- A.Produce vitamin D
- B.Produce sebum
- C.Waterproof the skin
- D.Provide protection against the sun's UV
- 62 marks
Ali was injected with penicillin through the skin using hypodermic needle. The first integumentary structure through which the needle passed was _____
- A.Reticular layer
- B.Epidermis
- C.Papillary layer
- D.Hypodermis
- 72 marks
In humans, all are the function of the skin except _____
- A.Respiratory gas exchange
- B.Preventing unnecessary water loss
- C.Excretion
- D.Regulation of body temperature
- 82 marks
A type of bone that is classified as irregular bone is known as _____
- A.Leg bones
- B.Vertebrae
- C.Skull
- D.Wrist bones
- 92 marks
Which of the following is NOT part of the appendicular skeleton
- A.Shoulder
- B.Hips
- C.Feet
- D.skull
- 102 marks
_____ releases excess water that helps the skin to regulate body temperature
- A.Sweat gland
- B.Sebaceous gland
- C.Oil gland
- D.Ceruminous gland
- 112 marks
Ali has eaten a bread for breakfast, the glucose level of his blood will:
- A.Increase
- B.Decrease
- C.Remains the same
- D.Decrease and increase
- 122 marks
The thyroxine hormone is secreted by _____
- A.Pituitary gland
- B.Adrenal gland
- C.Thyroid gland
- D.Parathyroid gland
- 132 marks
The tough outer membrane covering the brain and spinal cord of vertebrates is called _____
- A.The dura mater
- B.The pia mater
- C.Arachnoid mater
- D.Cerebrospinal fluid
- 142 marks
If one strand of a DNA is 5' ATCGTTAAGCGAGTCA 3' the complimentary strand would be:
- A.3' TAGCAATTCGCTCAGT 5'
- B.3' ACTGAGCGAATTGCTA 5'
- C.3' TGACTCGCTTAACGAT 5'
- D.3' ATCGTTAAGCGAGTCA 5'
- 152 marks
A black Ox (Bb) was crossed with a white cow (bb). Identify the resulting phenotypic ratio.
- A.0:1 black to white
- B.1:1 black to white
- C.1:0 black to white
- D.3:1 black to white
- 162 marks
According to Mendel the crossing between purple flower (PP) and a white flower (pp) results the F1 generation becoming:
- A.All white
- B.All purple
- C.3 purple:1white
- D.1purple:2white
- 172 marks
Which of the following regions in Somalia do you expect to find a greater species diversity?
- A.Galgudud
- B.Benadir
- C.Bari
- D.Lower Juba
- 182 marks
The groups of organisms that contain the largest estimated number of species are _____
- A.Birds
- B.Plants
- C.Insects
- D.Mammals
- 192 marks
Study the figure shown below, mention the part of the ear that is responsible for hearing:
- A.Semicircular canal
- B.Tympanum
- C.Cochlea
- D.Ear canal
- 202 marks
Farah whose blood group is A heterozygous marries Fatima whose blood group is B heterozygous, what is the probability that one of their children become O.
- A.25%
- B.50%
- C.75%
- D.100%
Section B (10 Marks)
Relate the terms in column A with the meanings or function in column B using numbers
- B10 marks
Relate the terms in column A with the meanings or function in column B using numbers. Column A: 1. Meninges 2. Cerebrum 3. Cerebrospinal fluid 4. Hypothyroidism 5. Genomics 6. Synovial fluids 7. Joint 8. Codon 9. DDT 10. ABO blood group system. Column B: ( ) The largest and most complex part of the brain; ( ) the fluid that provides oxygen and nutrients to the brain; ( ) The layer that covers the brain and spinal cord; ( ) the study of organism's genome; ( ) Thyroid hormone deficiency; ( ) the place where two bones meet; ( ) Lubricating substances found in joints; ( ) Example of codominance and multiple alleles; ( ) The triple base of the mRNA; ( ) dichloro-diphenyl trichloethane.
Section C (50 Marks)
- C1a2 marks
Define the following terms: (4 marks) a. Mutation
- C1b2 marks
Define the following terms: (4 marks) b. Neuron
- C2a3 marks
State the two abnormalities related to the following thyroid activities. (6 Marks) a. Hypothyroidism
- C2b3 marks
State the two abnormalities related to the following thyroid activities. (6 Marks) b. Hyperthyroidism
- C3a4 marks
a) Differentiate between lipophilic and hydrophilic hormones (4 marks)
- C3b2 marks
b) Give examples of lipophilic hormones. (2 marks)
- C4a3 marks
a) Define the term genetic engineering (3 Marks)
- C4b4 marks
b) Genetic engineering uses many methods and tools, list any four of them. (4 marks)
- C54 marks
Differentiate between species diversity and genetic diversity (4 marks)
- C6a2 marks
List two examples of: (4 marks) a. Steroid hormones
- C6b2 marks
List two examples of: (4 marks) b. Non steroid hormones
- C74 marks
Differentiate between type I diabetes and type II diabetes. (4 marks)
- C84 marks
In the diagram below indicate the lobes of the human brain and name the parts that are numbered A, B, C and D. (4 marks)
- C97 marks
A colour blind man (X^nY) marries a carrier woman (X^NX^n). What is the probability that their children will be colour blind? (7 marks)
- C104 marks
The flow chart below indicates the parts of the nervous system. Complete the missing parts in the boxes (4 marks). Nervous system divides into [box 1] and Peripheral Nervous system; [box 1] divides into [box 2] and Spinal cord; Peripheral Nervous system divides into [box 3] and Sensory division; [box 3] divides into [box 4] and Somatic nervous system.
Paper set by the Federal Ministry of Education, Culture and Higher Education (MoECHE), Somalia. Shared free of charge to help students prepare. The answers and explanations are written by Sheerxirfad teachers.
