CSEC Human and Social Biology Paper 1 January 2021 - Free CXC Past Paper with Answers

skin and hair

blood and the brain

trachea and the oesophagus

alveoli and blood capillaries

turtle

jellyfish

zooplankton

phytoplankton

blue-black

brown

green

white

I

II

III

IV

36

54

75

103

Scurvy

Rickets

Beri-beri

Night blindness

Biuret reagent

Iodide solution

Benedict's solution

Grease spot emulsion

dissolve fats

break down fibre

transport substances

dissolve vitamins A and D

headache

dehydration

constipation

poor hygiene

small intestine is acidic

stomach juice is alkaline

action of pepsin is affected by temperature

small intestine has a different pH from the stomach

fats

sugar

starch

protein

Egg

Liver

Carrot

Broccoli

Root

Crown

Cement

Pulp cavity

Smoking reduces the oxygen-carrying capacity of blood.

Smoking increases the oxygen-carrying capacity of blood.

Smoking does not affect the oxygen-carrying capacity of blood.

Smoking increases and then decreases the oxygen-carrying capacity of blood.

Pinch the person's nostrils to prevent air from escaping.

Place the person on his stomach with his head tilting downwards.

Place the person on his back and press back his forehead with one hand.

Take a deep breath and start breathing into the person's mouth immediately.

I and II only

I and III only

II and III only

I, II and III

I

II

III

IV

presence of platelets

presence of haemoglobin

size of the red blood cells

absence of nuclei in the cells

lower the pressure of blood

increase the pressure of blood

prevent the back flow of blood

push the blood back to the heart

Plasma

Platelet

Red blood cell

White blood cell

nutrients, heat and fibre

oxygen, hormones and glycogen

nutrients, nitrogenous waste and oxygen

oxygen, starch and nitrogenous waste

Coagulation of blood

Production of plasma proteins

Maintenance of extracellular fluid homeostasis

Filtration and destruction of harmful organisms

I and II only

I and III only

II and III only

I, II and III

Misalignment of the bones in the feet

Widening of the spaces between the toes

Development of corns and calluses on the toes

Reduction of the support placed on the heels of the feet

at the elbow

between wrist bones

between the skull and the neck

where the arm meets the shoulder

proximal convoluted tube

Bowman's capsule

loop of Henlé

glomerulus

protect the spinal cord

produce red blood cells

facilitate muscle attachment

support the girdles in the body

agestion

excretion

homeostasis

osmoregulation

cortex

cerebellum

hypothalamus

medulla oblongata

form urine

Absorb bile

pump blood to the lungs.

reduce blood sugar levels

use of convex lenses

use of concave lenses

intake of daily supplements of vitamin A

replacement of the eye lens by means of surgery

A nerve impulse has to be started in the brain.

A person has to actively decide to make a movement.

A movement of action is unconsciously performed all the time.

A nerve impulse will pass down the white matter of the spinal cord.

myopia

astigmatism

conjunctivitis

accommodation

uterus

placenta

amniotic sac

umbilical cord

Ovary

Thyroid

Pancreas

Pituitary

cerebrum

cerebellum

hypothalamus

olfactory lobe

I

II

III

IV

Pill

IUD

Diaphragm

Female condom

Implantation of the embryo

Nourishment of the embryo

Protection of the embryo

Expulsion of the embryo

fission

mitosis

meiosis

fertilization

height

foot length

skin colour

tongue rolling

Insulin

Thyroxine

Testosterone

Progesterone

all TT

½ TT and ½ Tt

½ TT and ½ tt

¾ TT and ¼ Tt

Rat

Ant

Locust

Termite

sharing personal items and walking barefooted in changing rooms

spitting and sneezing around others in a poorly ventilated room

sharing utensils and having blood transfusions

eating contaminated food in public places

Asthma

Diabetes

Influenza

Hypertension

steriod

narcotic

sedative

stimulant

I and II only

I and III only

II and III only

I, II and III

Encouraging them to have fewer sexual partners

Encouraging them to use latex condoms during sexual activity

Reducing their chances of coming into contact with infected blood

Using drugs to treat the disease that occurs because their immune systems are damaged

Adult (A)

Eggs

Larva (C)

Pupa (D)

natural active

natural passive

artificial active

artificial passive

Rats

Houseflies

Anopheles mosquitoes

Aedes aegypti mosquitoes

Using a fine strainer

Using chloramine tablets

Boiling for at least five minutes

Adding a small amount of bleach

encouraging the breeding of mosquitoes

encouraging rodents to frequent water sources

allowing the seepage of raw sewage into the water table

causing the discolouration of water in wells, streams and rivers

Broken down by chemicals to less harmful materials

Can be broken down by sunlight to less harmful materials

Broken down by living organisms to less harmful materials

Unable to be broken down by living organisms to less harmful materials

smog

acid rain

eutrophication

global warming

35

45

100

110

in which solid wastes are spread out in thin layers and compacted

in which garbage and sewage are dumped

which is filled with dirt and other material

in which sewage is treated