Form 4 Biology national exam 2024/2025 with answers
The 2024/2025 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.
- 62 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. Read each question carefully before answering. Write your answers on the exam paper. Time: 2 hours.
Section A: Multiple choice questions
40 Marks
- 11 mark
The peripheral nervous system consists of:
- A.Brain and spinal cord
- B.Cranial and spinal nerves
- C.Spinal cord and spinal nerves
- D.Cranial nerves and spinal cord
- 21 mark
The point at which the nerve impulse passes from the pre-synaptic neuron to the post-synaptic neuron is known as:
- A.Synaptic knob
- B.Synaptic vesicles
- C.Synaptic cleft
- D.Synaptic terminal
- 31 mark
When you sleep your special room in your house, which part of nervous system works?
- A.Parasympathetic
- B.Sympathetic
- C.Somatic
- D.Autonomic
- 41 mark
Suppose a person holding a very hot object and does not feel a burning pain in his hand. Which of the following neurons are probably damaged in his hand?
- A.Connectors
- B.Sensory
- C.Motor
- D.Neuron
- 51 mark
Ali has eaten bread as breakfast; His blood glucose level will decrease after two hours. which hormone regulates blood sugar level;
- A.Insulin
- B.Thyroxin
- C.Calcitonin
- D.Melatonin
- 61 mark
The gland which enlarges into a goiter as a result of iodine deficiency is:
- A.Adrenal
- B.Parathyroid
- C.Pineal
- D.Thyroid
- 71 mark
The number of true ribs in the human body are:
- A.12 Ribs
- B.14 Ribs
- C.16 Ribs
- D.18 Ribs
- 81 mark
The diagram below shows layers and associated structures of the skin. Which tissue type is responsible for standing the hair upright?
- A.A
- B.B
- C.C
- D.D
- 91 mark
An injection is administrated through the skin using a hypodermic needle. Identify the first integumentary structure through which the needle will pass:
- A.Epidermis
- B.Dermis
- C.Reticular layer
- D.Papillary layer
- 101 mark
The diagram below shows the human skeleton, What is the total number of bones in the lower limbs?
- A.30
- B.60
- C.40
- D.80
- 111 mark
The process by which the genetic instructions in specific gene are rewritten into RNA molecule is known as:
- A.Translation
- B.Termination
- C.Transcription
- D.Trasnlocation
- 131 mark
A genetic disease caused by a recessive gene mutation on chromosome number 14 is called:
- A.Phenylketonuria
- B.Krabbe disease
- C.Color blindness
- D.Hemophilia
- 141 mark
What determines gender in human?
- A.The X chromosome
- B.The Y chromosome
- C.The X and Y chromosomes
- D.Chromosome 21
- 151 mark
As a donor, the blood group A is incompatible with blood group B and O Because both makes:
- A.Anti-B antibodies
- B.Anti-A antibodies
- C.Anti- A antigens
- D.Anti-B antigens
- 161 mark
What is the basis of separation of different DNA fragments by gel electrophoresis?
- A.Size of the DNA fragments
- B.The presence of a dye
- C.The sequence of the fragments
- D.The positive charge on DNA
- 171 mark
The diagram below is a machine used in the amplification of DNA. Identify the name of the machine:
- A.PCR machine
- B.Sequencing machine
- C.Gel electrophoresis
- D.CRP machine
- 181 mark
Which of the following is a major threat of biodiversity?
- A.Pollution
- B.Genetic diversity
- C.Seed dispersal
- D.Habitat destruction
- 191 mark
Which term best describes what the two caws in the photo below demonstrates?
- A.Ecosystem diversity
- B.Genetic Diversity
- C.Species diversity
- D.Species richness
- 201 mark
Which one the following diseases can result from water pollution?
- A.Cholera
- B.Measles
- C.Malaria
- D.Mumps
- 211 mark
A person's heart rate increases rapidly after a frightening experience. Which part of the nervous system is responsible for this reaction?
- A.Sympathetic nervous system
- B.Parasympathetic nervous system
- C.Somatic nervous system
- D.Central nervous system
- 221 mark
A patient with diabetes is given insulin injection regularly. What is the main function of insulin in the body?
- A.Break down proteins
- B.Lowers blood glucose level
- C.Increases fat storage
- D.Stimulates muscle growth
- 231 mark
It is known that the total amount of DNA in a cell contains 300 nucleotides and Adenine contributes to 80 of these. How many nucleotides go to Guanine?
- A.70
- B.80
- C.120
- D.140
- 241 mark
If a homozygous dominant parent (TT) crosses with a homozygous recessive (tt). What will genotype of the offspring be?
- A.TT
- B.Tt
- C.tt
- D.tT
- 251 mark
An athlete consumes sports drinks containing glucose. What is the primary function of Carbohydrates in the body:
- A.Protein synthesis
- B.DNA replication
- C.Energy production
- D.Fat storage
- 261 mark
What are the building blocks of proteins;
- A.Organic acids
- B.Nucleic acids
- C.Fatty Acids
- D.Amino acids
- 271 mark
In human, fertilization occurs in the _____
- A.Oviduct
- B.Uterus
- C.Vagina
- D.Cervix
- 281 mark
_____ is an X linked recessive disorder defined by the absence of one or more of the proteins required for blood clotting.
- A.Color blindness
- B.Albinism
- C.Hemophilia
- D.Cystic Fibrosis
- 291 mark
Which of the following classes of vertebrates is characterized by feathers and the ability to fly?
- A.Birds
- B.Reptiles
- C.Amphibians
- D.Mammals
- 301 mark
How can you help flowers in your garden get pollinated?
- A.By watering them daily
- B.By planting flowers that attract pollinators
- C.By using chemical pesticides
- D.By keeping them indoors.
- 311 mark
What is the main difference between identical twins and non-identical twins?
- A.Identical twins share the same birthday
- B.Non-identical twins come from one egg
- C.Identical twins come from one egg that splits.
- D.Non-identical twins are always the same Gender.
- 321 mark
Color blindness is due to an X-linked recessive gene. Suppose a heterozygous woman for colorblindness marries a normal man. What proportion of their children will be color blind?
- A.All the daughters
- B.All the sons
- C.Half the daughters
- D.Half the sons
- 331 mark
Which of the following fungi can help fermentation of the bread?
- A.Yeast
- B.Mushroom
- C.Penicillium
- D.Morella
- 341 mark
Amino acids of a protein are joined together by a particular bond known as:
- A.Peptide bond
- B.Hydrogen bond
- C.Phosphodiester bond
- D.Covalent bond
- 351 mark
The diagram below shows the human heart with four chambers and four blood vessels labeled. Which chamber pumps oxygenated blood away from the heart?
- A.S
- B.T
- C.Y
- D.Z
- 361 mark
Which component of circulatory system is responsible for carrying deoxygenated blood towards the heart?
- A.Veins
- B.Capillaries
- C.Arteries
- D.Atriums
- 371 mark
Which scenario best illustrates the importance of studying biology in the medical field?
- A.Understanding patient behavior
- B.Understanding human anatomy and disease mechanisms
- C.Studying medical ethics
- D.Studying Agriculture.
- 381 mark
Which of the following is NOT a type of plant tissue?
- A.Parenchyma
- B.Xylem
- C.Cartilage
- D.Phloem
- 391 mark
Which level of biological organization comes directly after tissue?
- A.Cell
- B.Organ
- C.Organ system
- D.Organism
- 401 mark
Why viruses are considered non-living by many scientists?
- A.Because they are two small
- B.Because they do not reproduce on their own
- C.Because they not have a nucleus
- D.Because they lack of cytoplasm
Section B: Structural Questions
- 412 marks
Define Biodiversity and list factors that threaten biodiversity.
- 42a2 marks
Describe the uses of the following tools in genetic engineering: a. Restriction enzyme
- 42b2 marks
Describe the uses of the following tools in genetic engineering: b. Gene cloning
- 43a2 marks
The diagram below shows part of human skeleton viewed from behind: a. Name the parts labeled A, B, C, D and E.
- 43b2 marks
The diagram below shows part of human skeleton viewed from behind: b. Name the type of joints found at the shoulder.
- 444 marks
Explain briefly the difference between fast-twitch and slow twitch muscles?
- 45a2 marks
Look at this figure and then answer the questions that flow: a. Name the gland which produces estrogen.
- 45b2 marks
Look at this figure and then answer the questions that flow: b. Name three hormones produced from thyroid gland.
- 464 marks
A student fell while playing football and broken his leg. Describe the process that body undergoes to repair the broken bone?
- 474 marks
Compare the structure of DNA and RNA, highlighting their similarities and differences.
- 484 marks
A man with type AB blood is married to a woman with type O blood. They have two natural children and one adopted child. Ahmed has type A blood, Ali has type B blood and Aisha has type O. Which child was adopted?
- 49a2 marks
The diagram below shows the structure of the neuron. a. Name the parts of neurons labeled 1, 2, 3 and 5.
- 49b2 marks
The diagram below shows the structure of the neuron. b. Describe the function of the parts 2 and 3.
- 504 marks
Briefly explain the difference between lichens and mychorrhiza.
- 51a2 marks
The diagram below shows the structure of a flower: a. Where are the male gametes produced?
- 51b2 marks
The diagram below shows the structure of a flower: b. Which part develops into fruit after fertilization?
- 52a2 marks
Hemophilia is caused by an X-linked recessive gene. If a hemophiliac man marries a carrier woman: a. What is the probability that their son will have hemophilia?
- 52b2 marks
Hemophilia is caused by an X-linked recessive gene. If a hemophiliac man marries a carrier woman: b. What is the probability that their daughter will have hemophilia?
- 52c2 marks
Hemophilia is caused by an X-linked recessive gene. If a hemophiliac man marries a carrier woman: c. What is the probability that their daughter will be carrier?
- 534 marks
Explain how intracellular enzymes differ from extracellular enzymes.
- 54a2 marks
The diagram below shows the human digestive system. a. Name the parts labeled A, B, C, D and E.
- 54b2 marks
The diagram below shows the human digestive system. b. State the function of the part labeled D in the digestive system.
- 554 marks
Briefly explain the importance of protista.
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.
