senior exam nig - African Biology Olympiad

#1. Where in the digestive system is digested food absorbed into the blood?

Small Intestine

Stomach

Oesophagus

Large Intestine

#2. In an investigation, a pondweed is placed closer to a light source. What is the independent variable?

The type of pondweed

The light intensity

The amount of oxygen produced

The temperature of the water

#3. Which enzyme breaks down starch into sugars?

Protease

Lipase

Bile

Amylase

#4. The main function of the large intestine is to:

Digest proteins

Produce enzymes

Emulsify fats

Absorb water

#5. Which type of respiration does not require oxygen?

Photosynthesis

Anaerobic respiration

Gas exchange

Aerobic respiration

#6. Rose Black Spot is a disease caused by a:

Protist

Bacterium

Virus

Fungus

#7. What is the main function of the ribosomes?

Energy release

Storage of cell sap

Protein synthesis

Control of the cell's activities

#8. In a genetic cross, the allele for brown eyes (B) is dominant to the allele for blue eyes (b). What is the genotype of a homozygous, brown-eyed individual?

B

Bb

BB

bb

#9. What is the function of the hormone insulin?

To prepare the body for fight or flight.

To decrease blood glucose levels by converting glucose to glycogen in the liver.

To control the menstrual cycle.

To increase blood glucose levels.

#10. How many chromosomes are found in a human gamete (sperm or egg cell)?

2

46

23

92

#11. Tobacco Mosaic Virus (TMV) affects plants. What is a symptom?

Black spots on leaves

A mosaic pattern of discolouration on the leaves

Stunted growth

Root rot

#12. What is the name of the gap between two neurons where impulses are transmitted chemically?

Axon

Nucleus

Dendrite

Synapse

#13. Which part of the eye contains light-sensitive cells (rods and cones)?

Retina

Lens

Iris

Cornea

#14. Calculate the magnification if the image size is 5mm and the real size is 0.002mm.

x5000

x250

x2500

x500

#15. Type 1 diabetes is a condition where the pancreas produces little or no insulin. How is it typically treated?

By taking tablets to reduce sugar absorption.

By a controlled diet and exercise.

By transplanting a new pancreas.

By insulin injections.

#16. Which type of tissue covers the surfaces of organs?

Epithelial tissue

Muscular tissue

Glandular tissue

Nervous tissue

#17. In the menstrual cycle, which hormone causes the lining of the uterus to build up?

Follicle-Stimulating Hormone (FSH)

Oestrogen

Luteinising Hormone (LH)

Progesterone

#18. What is the role of negative feedback in homeostasis?

To initiate a new process unrelated to the change.

To detect a change and bring the system back to its normal level.

To ignore small changes in the internal environment.

To amplify a change away from the normal level.

#19. Which process returns carbon dioxide to the atmosphere?

Nitrogen fixation

Consumption

Respiration

Photosynthesis

#20. What is the function of xylem tissue in plants?

To transport sucrose

To transport water and mineral ions

To carry out photosynthesis

To absorb light

#21. How can the spread of Salmonella food poisoning be reduced?

Using fungicides

Using mosquito nets

Vaccinating chickens

Washing hands after gardening

#22. What is a causal mechanism?

A correlation between two factors.

Something that increases the risk of developing a disease.

A type of treatment.

How one factor influences another to cause a disease.

#23. What is the purpose of pre-clinical testing of a new drug?

To test on human patients

To see if doctors like the drug

To test for toxicity and efficacy in a lab using cells, tissues and live animals

To mass-produce the drug

#24. What is the name of the process where a white blood cell surrounds and engulfs a pathogen?

Phagocytosis

Antitoxin production

Antibody production

Vaccination

#25. Which process is used to produce a genetically identical copy of an organism?

Cloning

Natural Selection

Sexual Reproduction

Speciation

#26. What happens to most of the energy as it is transferred from one trophic level to the next in a food chain?

It is recycled by decomposers.

It is lost as heat during respiration, movement, and other life processes.

It is stored in the consumer's body.

It is passed on to the next consumer.

#27. What is the green pigment in chloroplasts that absorbs light?

Hemoglobin

Melanin

Carotene

Chlorophyll

#28. A section of DNA that codes for a specific protein is called a:

Allele

Nucleus

Chromosome

Gene

#29. What is the function of the permanent vacuole in a plant cell?

To control the cell

To make proteins

To store cell sap and provide support

To carry out photosynthesis

#30. The formation of a new species often requires which of the following?

A sudden change in the environment that kills all life.

Geographical isolation of two populations.

Two populations to remain in the same environment.

All individuals in a population to have identical DNA.

#31. In which type of reproduction is mitosis the main form of cell division?

Neither

Sexual reproduction

Both sexual and asexual

Asexual reproduction

#32. What is glucose converted into for storage in plants?

Protein

Lipids

Starch

Cellulose

#33. Which organ produces bile?

Stomach

Liver

Pancreas

Gall Bladder

#34. What is biodiversity?

The number of plants in an area.

The study of life.

The variety of all the different species of organisms on Earth or within an ecosystem.

The number of animals in an area.

#35. What is a use of the glucose produced in photosynthesis?

Stored in the liver

Used in respiration

Released as oxygen

Used to make cell walls (cellulose)

#36. What is the main concern about the overuse of antibiotics?

They cause viruses to become stronger.

They lead to the development of antibiotic-resistant strains of bacteria.

They are too expensive.

They become less effective.

#37. Which of the following is a result of meiosis?

Production of gametes (sex cells)

Growth and repair of tissues

Asexual reproduction in bacteria

Production of genetically identical cells

#38. What is the function of red blood cells?

To carry blood plasma

To carry oxygen

To form clots

To fight infection

#39. Which hormone is released by the adrenal glands in response to stress?

Insulin

Adrenaline

Progesterone

Testosterone

#40. A person who does not smoke, has a balanced diet, and exercises regularly is:

Completely immune to all diseases.

Less likely to develop certain non-communicable diseases.

Guaranteed to never get a non-communicable disease.

More likely to get infectious diseases.

#41. Which component of blood is responsible for clotting?

Red Blood Cells

Plasma

Platelets

White Blood Cells

#42. Which of the following is a major threat to biodiversity?

Habitat destruction

Sustainable resource use

Conservation programs

Increased recycling

#43. What happens during the ‘metaphase’ stage of mitosis?

Chromosomes are pulled apart to opposite poles.

Chromosomes line up at the equator of the cell.

Two new nuclei form.

The nuclear envelope breaks down.

#44. What is a vaccine?

A chemical that produces toxins

A small dose of a dead or inactive pathogen

A medicine that kills bacteria

A type of white blood cell

#45. Which organ is most directly damaged by heavy alcohol consumption?

The Lungs

The Liver

The Brain

The Heart

#46. Why are antibiotics ineffective against viral diseases like the common cold?

Viruses are not living organisms.

Viruses are too small.

Viruses are resistant to all drugs.

Antibiotics cannot destroy viruses because they live inside body cells.

#47. What is a stem cell?

A cell that is fully specialised.

A type of nerve cell.

A cell that is only found in embryos.

An undifferentiated cell that can divide to produce more stem cells or other cell types.

#48. In a double-blind trial, who does not know which patients received the placebo and which received the real drug?

Only the patients

The government

Only the doctors

Both the patients and the doctors

#49. What is the word equation for photosynthesis?

Glucose + Oxygen → Carbon Dioxide + Water

Carbon Dioxide + Glucose → Oxygen + Water

Oxygen + Water → Glucose + Carbon Dioxide

Carbon Dioxide + Water → Glucose + Oxygen

#50. Where in the cell does most aerobic respiration take place?

Chloroplast

Mitochondrion

Nucleus

Ribosome

#51. Which gland is known as the ‘master gland’ because it secretes several hormones that control other glands?

Pituitary gland

Thyroid gland

Adrenal gland

Pancreas

#52. What is the function of bile?

To digest proteins

To emulsify fats and neutralise stomach acid

To digest starch

To absorb water

#53. The loss of water vapour from plant leaves is called:

Translocation

Transpiration

Transportation

Respiration

#54. Where is protease enzyme produced?

Large Intestine

Pancreas

Salivary Glands

Gall Bladder

#55. What is the main problem with the overuse of antibiotics?

They become more expensive.

They start to kill viruses.

They cause allergies in everyone.

They lead to the development of antibiotic-resistant strains of bacteria.

#56. Which type of tumour is benign?

A tumour caused by a virus.

A tumour that is always harmless.

A tumour that invades neighbouring tissues and can spread.

A tumour that grows slowly and remains in one place.

#57. What is the correct order of a simple reflex arc?

Sensory Neurone → Receptor → Effector → Motor Neurone → Relay Neurone

Effector → Motor Neurone → Relay Neurone → Sensory Neurone → Receptor

Receptor → Motor Neurone → Relay Neurone → Sensory Neurone → Effector

Receptor → Sensory Neurone → Relay Neurone → Motor Neurone → Effector

#58. How does temperature affect the rate of photosynthesis?

As temperature increases, the rate always increases.

As temperature increases, the rate always decreases.

The rate increases up to an optimum, then decreases as enzymes denature.

Temperature has no effect.

#59. Which of the following is a risk factor for non-communicable diseases?

Being infected by a pathogen

Smoking

Washing your hands

Having a vaccination

#60. What is the role of hydrochloric acid in the stomach?

To emulsify fats

To digest food

To kill bacteria and provide the optimum pH for protease

To absorb nutrients

#61. What is ‘herd immunity’?

When antibiotics are used on farm animals.

When a large proportion of the population is vaccinated, reducing the spread of the disease.

When everyone in a population catches a disease.

When animals are immune to human diseases.

#62. How do most contraceptive pills prevent pregnancy?

They kill sperm.

They contain oestrogen which inhibits FSH production, so no eggs mature.

They create a barrier to the egg.

They make the uterus lining inhospitable.

#63. What is the link between diet and cancer?

A poor diet can directly cause cancer in all cases.

Only a high-sugar diet is linked to cancer.

Obesity is a risk factor for some types of cancer.

There is no link between diet and cancer.

#64. Which of the following is a biotic factor in an ecosystem?

Soil pH

Temperature

Light intensity

Competition for food

#65. Which factor is not a limiting factor of photosynthesis?

Temperature

Oxygen concentration

Carbon dioxide concentration

Light intensity

#66. What is the product of protein digestion?

Glycerol

Fatty Acids

Amino Acids

Sugars

#67. A sperm cell is adapted for swimming to an egg cell. Which cell structure provides the energy for this movement?

Ribosome

Cell membrane

Mitochondria

Nucleus

#68. What is the term for all the organisms of one species in a habitat?

Ecosystem

Environment

Population

Community

#69. In a food chain, what is the name given to the organism that gets its energy directly from the sun?

Decomposer

Primary Consumer

Producer

Secondary Consumer

#70. What is the correct order of the stages of mitosis?

Anaphase, Telophase, Metaphase, Prophase

Prophase, Metaphase, Anaphase, Telophase

Metaphase, Prophase, Telophase, Anaphase

Prophase, Metaphase, Telophase, Anaphase

#71. What is the role of the coronary arteries?

To supply blood to the heart muscle itself

To supply blood to the lungs

To pump blood

To carry deoxygenated blood to the heart

#72. Which process in the water cycle involves the change of water from a liquid to a vapour?

Transpiration

Precipitation

Evaporation

Condensation

#73. How are the alveoli adapted for gas exchange?

Moist lining

Thick walls

Small surface area

Poor blood supply

#74. Assume a graph showing blood glucose levels after a meal. Which process is happening at point X where the level is decreasing? (Assume a graph showing a peak then a decline)

Insulin is being released.

Glycogen is being converted to glucose.

Glucose is being released from the liver.

Glucagon is being released.

#75. Which of the following is a benefit of maintaining biodiversity?

It protects potential future resources like medicines.

It makes it easier for diseases to spread.

It makes ecosystems less stable.

It reduces the number of species.

#76. How does the body respond to exercise?

Breathing rate decreases

The arteries to the muscles dilate

Blood flow to the gut increases

Heart rate decreases

#77. Which part of the brain is responsible for coordinating muscle activity and balance

Medulla

Cerebrum

Cerebellum

Pituitary gland

#78. What does the term ‘survival of the fittest’ mean?

The strongest individuals always survive.

The biggest individuals get the most resources.

Individuals with characteristics best suited to their environment are more likely to survive and reproduce.

Only the fastest individuals survive.

#79. Which organ system is the stomach part of?

Digestive System

Nervous System

Respiratory System

Circulatory System

#80. A sperm cell is a gamete. How many chromosomes does it contain?

92

46

23

0

#81. A plant is kept in the dark for 48 hours. What will happen to the rate of photosynthesis?

It will increase.

It will decrease.

It will stop completely.

It will stay the same.

#82. Which of the following has the highest magnification?

A light microscope

An electron microscope

A camera lens

A magnifying glass

#83. Lipase enzymes break down lipids (fats) into:

Amino Acids and Glycerol

Glycerol and Sugars

Sugars and Fatty Acids

Fatty Acids and Glycerol

#84. What is the term for all the populations of different species living and interacting in a particular place?

Environment

Ecosystem

Population

Community

#85. Why do plants need nitrate ions?

For respiration

For photosynthesis

To make proteins

To make chlorophyll

#86. What is the correct order of organisation in a multicellular organism?

Organ → Cell → Tissue → Organ System

Organ System → Organ → Tissue → Cell

Tissue → Cell → Organ System → Organ

Cell → Tissue → Organ → Organ System

#87. Which chamber of the heart pumps blood to the lungs?

Left Ventricle

Left Atrium

Right Atrium

Right Ventricle

#88. What is an advantage of aerobic respiration over anaerobic respiration?

It is faster.

It releases more energy per glucose molecule.

It produces lactic acid.

It does not require oxygen.

#89. What is the main role of decomposers like bacteria and fungi in an ecosystem?

To act as primary consumers.

To break down dead organisms and waste materials, recycling nutrients.

To capture energy from the sun.

To produce oxygen.

#90. What is the role of white blood cells in defence against disease?

Clotting blood

Phagocytosis

Endometriosis

Carrying oxygen

#91. What is the name for the method of using living organisms to control a pest population?

Biological Control

Genetic Engineering

Pesticide Control

Selective Breeding

#92. The process of cell division that produces two identical daughter cells is called:

Fertilisation

Meiosis

Differentiation

Mitosis

#93. How does the skin act as a defence against pathogens?

By producing toxins

By producing antibodies

By acting as a physical barrier

By engulfing bacteria

#94. What is the function of phloem tissue in plants?

To absorb minerals

To support the plant

To transport sucrose (dissolved sugars)

To transport water

#95. What is the primary purpose of respiration?

To release energy from glucose

To produce glucose

To produce oxygen

To absorb light

#96. Which process describes the movement of air into the lungs?

Respiration

Exhalation

Inhalation

Gas Exchange

#97. Liver cirrhosis is a non-communicable disease strongly linked to:

Lack of exercise

Smoking

Excessive alcohol consumption

A high-fat diet

#98. If two heterozygous, brown-eyed parents (Bb) have a child, what is the probability the child will have blue eyes?

50%

75%

25%

0%

#99. Which process produces gametes?

Fertilisation

Cloning

Mitosis

Meiosis

#100. Which of the following is an example of selective breeding?

A bird's beak shape changes over generations due to a change in available food.

A bacterium develops resistance to an antibiotic.

A plant is genetically modified to be resistant to herbicides.

A farmer crosses his best milk-producing cows to produce calves that yield more milk.

#101. What is the emergence of a new species from an existing one called?

Cloning

Fertilisation

Speciation

Variation

#102. What is the main purpose of a quadrat in ecological fieldwork?

To estimate the population size of a species in a given area.

To measure light intensity.

To capture small animals for study.

To measure soil pH.

#103. Which of these structures is found in a plant cell but not in an animal cell?

Cell wall

Nucleus

Cell membrane

Mitochondrion

#104. What is the definition of homeostasis?

The control of body temperature only.

The maintenance of a stable internal environment.

The way organisms control their surroundings.

The removal of waste products from the body.

#105. How is Cholera spread?

By droplet infection

By contaminated water

By the bite of a mosquito (vector)

By direct contact

#106. A build-up of fatty material in the arteries is called:

Cancer

Atherosclerosis

Thrombosis

Diabetes

#107. How can smoking lead to lung cancer?

Smoking has no link to cancer.

Smoking weakens the immune system, allowing a virus to cause cancer.

Carcinogens in tobacco smoke can cause mutations in DNA.

Smoking causes a vitamin deficiency.

#108. How many chromosomes are in a normal human body cell?

46

23

92

2

#109. A person gets chickenpox and then recovers. They are unlikely to get it again. What type of immunity is this?

Passive immunity

Natural active immunity

Artificial active immunity

Herd immunity

#110. What is the definition of evolution?

The way an individual changes during its lifetime.

The development of new species in one generation.

The extinction of a species.

The change in the inherited characteristics of a population over time.

#111. Which type of blood vessel has valves to prevent the backflow of blood?

Aorta

Vein

Artery

Capillary

#112. Which non-communicable disease is caused by a vitamin C deficiency?

Rickets

Beri-Beri

Scurvy

Anemia

#113. Which process is used by root hair cells to absorb mineral ions from the soil if the concentration in the cell is already higher than in the soil?

Diffusion

Osmosis

Evaporation

Active transport

#114. Which disease is spread by direct sexual contact?

Gonorrhoea

Malaria

Measles

Tuberculosis (TB)

#115. Why is meiosis important for sexual reproduction?

It increases genetic variation.

It only happens in plants.

It ensures the offspring has the same number of chromosomes as the parents.

It produces cells that are genetically identical.

#116. What is the word equation for aerobic respiration?

Glucose → Ethanol + Carbon Dioxide

Glucose → Lactic Acid

Glucose + Oxygen → Carbon Dioxide + Water

Carbon Dioxide + Water → Glucose + Oxygen

#117. In which organelle does photosynthesis take place?

Mitochondrion

Chloroplast

Ribosome

Nucleus

#118. Which of the following is a potential use of adult stem cells?

To create a whole new organism

To create plant clones

To treat conditions like sickle cell anaemia

They have no medical uses

#119. Diffusion is:

The movement of particles from an area of high concentration to an area of low concentration.

The movement of water from a dilute to a concentrated solution.

The movement of particles from an area of low concentration to an area of high concentration.

The movement of particles against a concentration gradient using energy.

#120. Where is the energy released in respiration transferred to?

A molecule called ATP

A molecule called Chlorophyll

A molecule called Glucose

A molecule called DNA

#121. Which type of drug was first discovered from the Penicillium mould?

Aspirin

Digitalis

Paracetamol

Penicillin

#122. Which of the following is a use of monoclonal antibodies?

To carry oxygen around the body

In pregnancy tests to detect hCG hormone

To treat vitamin deficiencies

To digest food

#123. What type of pathogen causes Lassa Fever?

Virus

Fungus

Protist

Bacterium

#124. Which activity would primarily use anaerobic respiration?

Sleeping

Sprinting 100m

Reading a book

Watching TV

#125. What is the name of the stage of the cell cycle where the cell grows and replicates its DNA?

Prophase

Mitosis

Interphase

Cytokinesis

#126. Which type of neuron carries impulses from a receptor to the central nervous system (CNS)?

Sensory neurone

Synaptic neurone

Relay neurone

Motor neurone

#127. Which substance moves into cells by osmosis?

Starch

Glucose

Water

Oxygen

#128. Where are chromosomes found in a cell?

Mitochondria

Nucleus

Cell membrane

Cytoplasm

#129. What is the source of energy for almost all life on Earth?

Water

Wind

The Sun

Soil

#130. Active transport requires which of the following?

Water molecules

A partially permeable membrane only

A concentration gradient only

Energy from respiration

#131. A red blood cell is placed in pure water. What will happen to it?

Shrink and become crinkled

Release oxygen

Swell and burst

Stay the same size

#132. HIV initially leads to a person being more susceptible to other infections because it attacks:

Red blood cells

The liver

The nervous system

The immune system (white blood cells)

#133. What is the molecule in the nucleus of a cell that carries genetic information?

ATP

Glucose

DNA

Protein

#134. Which mineral ion is needed to make chlorophyll?

Potassium

Nitrate

Magnesium

Phosphate

#135. In yeast, anaerobic respiration produces:

Lactic Acid

Oxygen and Water

Glucose only

Ethanol and Carbon Dioxide

#136. Which disease is caused by a virus and is spread by droplet infection?

Cholera

Rose Black Spot

Measles

Gonorrhoea

#137. What causes an ‘oxygen debt’ after vigorous exercise?

The body needs oxygen for photosynthesis.

The lack of oxygen during anaerobic respiration, requiring oxygen to break down the lactic acid.

The production of too much glucose.

The need to breathe in more carbon dioxide.

#138. The process of anaerobic respiration in yeast is called:

Fermentation

Photosynthesis

Digestion

Transpiration

#139. Producing monoclonal antibodies involves the fusion of a specific white blood cell with what type of cell?

A red blood cell

A liver cell

A skin cell

A tumour cell

#140. Which blood vessel carries oxygenated blood away from the heart?

Capillary

Vein

Artery

Vena Cava

#141. Which of the following is a plant organ?

Mesophyll

Xylem

Leaf

Phloem

#142. Which scientist proposed the theory of evolution by natural selection?

Gregor Mendel

Charles Darwin

Carl Linnaeus

Jean-Baptiste Lamarck

#143. A surge in which hormone triggers ovulation (the release of an egg)?

Luteinising Hormone (LH)

Follicle-Stimulating Hormone (FSH)

Progesterone

Oestrogen

#144. In human muscles, what is the product of anaerobic respiration?

Oxygen and Glucose

Carbon Dioxide and Water

Ethanol and Carbon Dioxide

Lactic Acid

#145. What is a placebo?

A type of antibiotic

A substance that is like the drug but does not contain the active ingredient

A very strong dose of a drug

A vaccine

#146. What is the main advantage of sexual reproduction over asexual reproduction?

It produces genetically identical offspring.

It only requires one parent.

It produces genetic variation in the offspring.

It is faster.

#147. Which cell is adapted for transmitting electrical impulses?

Root hair cell

Palisade cell

Red blood cell

Nerve cell

#148. A plant with yellow leaves may be deficient in:

Phosphate ions

Nitrate ions

Magnesium ions

Water

#149. Which disease is characterised by the inability to control blood sugar levels?

Type 2 Diabetes

Coronary Heart Disease (CHD)

Scurvy

Cancer

#150. How do antibiotics work?

They kill bacteria.

They kill all types of pathogen.

They prevent disease by stimulating antibody production.

They kill viruses.