CSEC Human and Social Biology Paper 1 May/June 2026 - Free CXC Past Paper with Answers

The change in the red blood cell shown in II occurs because water

enters the cell by osmosis

leaves the cell by osmosis

enters the cell by diffusion

leaves the cell by diffusion

Which of the following features is NOT common to all living organisms?

Producing identical cells in reproduction

Getting rid of metabolic waste products

Releasing energy by a process of respiration

The MAIN function of the visking tube is to act as a

semipermeable membrane

Which of the following factors is NOT necessary for photosynthesis to take place?

Which organelle in muscle cells provides energy for contraction?

Which of the following statements is NOT true of anaemia?

It is caused by the presence of an extra chromosome.

It is caused by a lack of iron compounds in the diet.

It can be treated by eating green vegetables, liver and egg yolk.

It results from the manufacture of an inadequate number of red blood cells.

Which of the following reagents gives a positive test for the main food present in a slice of baked potato?

Which of the following foods would BEST prevent constipation?

Vegetable rice and fish

Fruit and vegetable salad

Wholewheat bread and cheese

Which of the foods above is MOST likely a cereal?

Which of the foods above is NOT suitable for a person suffering from arteriosclerosis?

Which of the following are properties of enzymes?

I. They mostly work on only one substrate. II. They are not affected by temperature. III. They work best at a particular pH.

Lisa has BMI of 24.5. She is considered to be

Which of the following types of teeth is BEST adapted for tearing tough pieces of food?

Which of the following vitamins is water-soluble?

The process of egestion is defined as the removal of

Which row in the table above correctly matches the structure with its function?

Epiglottis / Vibrates to make sounds

Larynx / Protects lungs and heart

Bronchus / Facilitates the passage of air to lungs

Ribcage / Prevents food from entering trachea

While climbing up a mountain, a group of hikers finds that breathing becomes difficult. This is MOST likely because

the air pressure decreases

they become tired from the long walk

they lose too much water by sweating

The equation for aerobic respiration is

$C_6H_{12}O_6 + 6O_2 \rightarrow 6CO_2 + 6H_2O + \text{energy}$

$C_6H_{12}O_6 + 6CO_2 \rightarrow 6O_2 + 6H_2O + \text{energy}$

$C_6H_{12}O_6 \rightarrow 2C_2H_5OH + 2CO_2 + \text{energy}$

$C_6H_{12}O_6 \rightarrow 2C_3H_6O_3 + \text{energy}$

During respiration, the release of energy in a cell occurs when

ATP is converted to ADP

ADP is converted to ATP

ADP is converted to lactic acid

ATP and oxygen form oxyhaemoglobin

Capillaries have very thin walls which have only one layer of cells. This is to allow the

slow diffusion of gases and glucose

rapid diffusion of gases and glucose

rapid diffusion of protein and fats

slow diffusion of protein and fats

Which of the following are true about phagocytes?

I. Have a rounded nucleus II. Engulf and ingest bacteria III. Are a type of white blood cell

The left side of the heart has a thicker muscular wall in order to

pump blood to the lungs

receive blood from the lungs

pump blood to the rest of the body

receive blood from the rest of the body

Which sequence of events needs to occur in order for a blood clot to form?

Thromboplastin $\rightarrow$ prothrombin $\rightarrow$ thrombin $\rightarrow$ fibrinogen $\rightarrow$ fibrin

Prothrombin $\rightarrow$ thromboplastin $\rightarrow$ thrombin $\rightarrow$ fibrinogen $\rightarrow$ fibrin

Fibrinogen $\rightarrow$ fibrin $\rightarrow$ thrombin $\rightarrow$ prothrombin $\rightarrow$ thromboplastin

Thromboplastin $\rightarrow$ thrombin $\rightarrow$ fibrin $\rightarrow$ prothrombin $\rightarrow$ fibrinogen

Coronary thrombosis occurs when

the valves in the heart stop working

there is too much blood flowing through the heart

a coronary artery becomes blocked with a blood clot

the coronary vein becomes blocked with a blood clot

Which of the following is a tough, flexible, fibrous connective tissue that joins two bones to form a stable joint?

Which of the following joints allows movement in all directions?

Which of the following combinations correctly identifies the bones labelled X, Y and Z?

Tibia / Femur / Fibula

Femur / Tibia / Fibula

Fibula / Tibia / Femur

Femur / Fibula / Tibia

The biceps are attached to the radius in the area known as the

Liam notices that his face is flushed (red) after playing football. Which of the following processes causes his face to be flushed?

Which labelled part collects filtrate from the glomerulus?

Which labelled part brings blood to the glomerulus?

Which of the following structures of the skin causes its hair to stand on end?

Which labelled part is the axon?

The central nervous system is made up of the

brain and spinal cord

brain and spinal nerves

brain and cranial nerves

spinal cord and cranial nerves

Which of the following is an involuntary action?

The part labelled X is the

Which row in the table above correctly matches the endocrine gland with the hormone it secretes?

Adrenal gland / Insulin

Pancreas / Thyroxine

Ovary / Progesterone

Thyroid / Growth hormones

The MAIN reason for practising family planning is to

make families healthier

improve the economy of a country

give family members more leisure time

ensure sufficient resources for each family member

Which of the following birth control methods is considered the LEAST reliable?

Implantation occurs when the fertilized ovum

is embedded in the uterus wall

Which of the following methods of female contraception functions by preventing sperm from entering the uterus?

Which of the following are true about the fallopian tube?

I. Produces the ovum II. Site where fertilization of the ovum occurs III. Facilitates the passage of the ovum to the uterus

Which of the following is an example of genetic engineering?

Using stem cells to produce organs

Tissue culture in banana production

Cloning of high-producing animals

Production of insulin by E. coli bacteria

Which of the following offspring inherited the homozygous recessive genotype?

Chromosomes are made up of protein and

Which of the following occurs when a zygote receives ONE extra chromosome?

Sex-linked inheritance

Incomplete dominance

A chromosomal mutation

Beriberi is an example of a disease that is classified as

sexually transmitted

nutritional deficiency

Good health may be BEST defined as

a state of complete physical and economic well-being

a state of complete physical, social and mental well-being

the absence of disease, as well as complete social well-being

the absence of disease, as well as complete physical well-being

Which of the following organisms is the causative agent for cholera?

Which of the following cells does the AIDS virus attack?

Which of the following stages are found in or on water?

Which of the following symptoms causes the MOST injury to a person suffering from dengue fever?

Internal haemorrhaging

Which of the following types of immunity occurs when a baby receives antibodies from its mother before birth?

Contamination of water sources is detrimental to humans because of the spread of water-borne diseases such as

Water pollution may be controlled by

educating the public and implementing laws

using nitrate fertilizers on crops planted near rivers

washing in rivers using detergents containing phosphates

pouring sewage into rivers after bacterial decomposition

Recycling may BEST be defined as

using a collected resource over and over in the same form

reprocessing a collected resource into new products

reducing the use of a resource

chemically altering a resource

What is the effect of carbon monoxide on the human body?

Prevents oxygen uptake by blood

Damages cilia present on the trachea

Causes eye irritation and reduced visibility

Has toxic effects on the nervous system

Which of the following is the correct sequence when testing water for bacteria?

I. Examine the agar in the petri dish for the presence of coliform colonies. II. Incubate the petri dish at $35\ ^\circ\text{C}$ for 24 hours. III. Place collected water in a sterile bottle. IV. Pour the water onto sterile agar in a sterile petri dish.

Transpiration is represented by

Which of the following is an example of a non-biodegradable pollutant?

CSEC Human and Social Biology Paper 1 May/June 2026 - Free CXC Past Paper with Answers

CSEC Human and Social Biology Paper 1 May/June 2026 Questions