CSEC Biology Paper 1 May/June 2006 - Free CXC Past Paper with Answers

Which of the following pairs of organisms is classified as carnivores?

Which of the following pairs of organisms is at the same trophic level?

The relationship between which of the following provides an example of mutualism?

Which level of the web will contain the largest energy reserve?

Item 5 refers to the following diagram of the nitrogen cycle. N₂ gas L Nitrates in soil Plant tissues Animal tissues

Which of the following groups of bacteria will be active at L?

If all the trees in a large area of forest were destroyed by disease, what would be the MOST likely effect on the composition of the air in the long term?

The level of carbon dioxide would decrease.

The level of carbon dioxide would increase.

. There would be no change in the composition of the air.

There would be more oxygen.

In multicellular organisms, cells become different from one another in order to carry out particular functions. This is called

Item 8 refers to the following diagrams which illustrate the result of an investigation.

Drop of dye Distilled water Start of experiment One hour later

The process demonstrated in the diagrams above is responsible for

minerals entering root cells

water entering root cells

carbon dioxide entering leaf cells

starch entering phloem cells

Items 9-10 refer to the following enzymes found in the human digestive system (A) Amylase (B) Pepsin (C) Lipase (D) Trypsin

Which enzyme would work best in an acid pH?

Which enzyme is concerned with the break-down of fat?

A food sample is boiled with dilute hydrochloric acid and neutralized. When tested with Benedict's solution, (or Fehling's), an orange red colour is produced. This indicates that the food containes

One of the problems with nutrition for a vegetarian is that

fats and oils are not produced by plants

large quantities of food are needed to supply essential amino acids

vitamins produced by plants are of inferior quality

large quantities of food are needed to supply essential mineral nutrients

The following diagrams are being used to demonstrate the action of a model of the human breathing system.

Which diagram correctly indicates what happens during exhalation?

The alveoli of the lungs of a mammal

keep the lungs filled to capacity continuously

serve to increase the absorptive surface of the lungs

are filled with oxygen to keep the lungs in an expanded state

prevent the lungs from collapsing

Which of the following BEST account for the fact that one usually gets tired during heavy exercise?

I. Energy is not easily liberated from mitochondria during heavy exercise. II. Oxygen cannot reach the muscle mitochondria fast enough. III. The level of lactic acid in the tissue is lowered. IV. The level of lactic acid in the tissue is increased.

Plants give off oxygen in the day because

respiration does not take place

respiration takes place faster than photosynthesis

photosynthesis takes place faster than respiration

transpiration takes place

The common form in which carbohydrate is transported in the blood is as

Which of the following comparisons between arteries and veins is NOT correct?

Have thick muscular walls / Have thin walls

Blood flows in pulses / Blood flows smoothly

Valves present / Valves absent

Blood low in carbon dioxide / Blood high in carbon dioxide

Which of the following sequences represents the route along which the blood flows after leaving the liver?

Liver → heart → lungs → body cells → heart

Liver → heart → lungs → heart → body cells

Liver → heart → body cells → lungs → heart

Liver → heart → body cells

Item 20 refers to the following diagram of an insect feeding on a plant.

The insect MOST likely obtains its nutrients from the

Which of the following cell structures would be found only in a plant cell?

I. Cell wall II. Vacuole III. Chloroplast IV. Endoplasmic reticulum

Which of the following are likely effects of cigarette smoking?

I. Lung cancer II. Inhibition of gaseous exchange III. Addiction IV. Hallucination

Where in the cycle would the hormone insulin be needed?

Which of the following statements about excretory products in plants are correct?

I. They are stored in leaves and bark. II. They are converted into insoluble crystals and tannins. III. They are removed during transpiration. IV. They result in the formation of storage organs.

The ureter carries urine from the

nephron to the collecting tubule

collecting tubule to the pelvis

kidney to the bladder

bladder out of the body

While the filtrate passes through the kidney tubule, most of the water moves back into the blood stream. This makes the filtrate

The function of the projections at 1 is for

attachment of muscles

giving the bone shape

secretion of synovial fluid

In which tubes will the ink drops move?

Which type of joints is found at the elbow?

Item 30 refers to the following diagram of the brain.

Which part of the brain, when affected, causes a drunken man to fall into a drain?

If an object is thrown towards you, your eyes blink. The receptors and effectors for this reflex action are the

retina and the eyelid muscles

retina and the ciliary muscles

pupil and the eyelid muscles

pupil and the ciliary muscles

Which one of the following is NOT involved in the reflex action of the body known as the knee-jerk reflex?

In which of the following regions in a young root will auxins have their greatest effect?

Zone of differentiation

Which of the following is NOT a function of bones?

Produce red blood cells

Act as lever systems in the body

Item 35 is based on the graph below which shows the height of some students in a class.

Which labelled portion of the graph represents the unusually short students?

In addition to energy, which of the following are products of aerobic respiration?

Carbon dioxide and water

Carbon dioxide and ethanol

Which of the following are good reasons for advising gardeners to use asexual rather than sexual methods to reproduce plants? They can obtain I. many new plants in a short time II. a wide variety of the offspring III. new plants which are identical to one another IV. many plants with desirable features

Which of the following are necessary for germination to take place?

I. Air II. Food supply III. Light IV. Moisture

The secretion from which of these glands would be associated with preparation of the body for rapid escape from danger?

During pregnancy, the developing foetus receives from its mother protection against infections, a perfectly balanced diet, warmth and oxygen. Which one of these can a mother no longer provide for her new-born infant?

Which of the following statements confirms that the coconut is a fruit?

It is dispersed by water.

It has a plumule and a radicle.

It has a three layered pericarp.

As a result of mitosis, each daughter cell has

half the number of chromosomes as the parent

the same number of chromosomes as the parent

twice the number of chromosomes as the parent

a variable number of chromosomes

Which of the following may give rise to new plant varieties? I. Mutations II. Mitosis III. Breeding

Which of the following is true about dominant alleles? They

do not undergo mutation

have more of a chance of survival than recessive genes

are responsible for male characteristics

give the same phenotype in heterozygous and homozygous individuals

In a particular plant, red and white flower-colour show co-dominance. If two heterozygous (pink) flowers are crossed, the expected phenotypic ratio of the offspring is

1 red: 2 pink: 1 white

Which of the following is an example of continuous variation in humans?

Natural selection differs from artificial selection because

the environment determines the individual with the beneficial trait

the environment determines the beneficial characteristics

it is a slower process

it involves non-random mating

Natural selection can be defined as the process by which natural populations

compete with other populations for survival

mutate in order to survive

remain well adapted to their habitat

gradually bring about changes in their habitat

Items 49-50 refer to an organism which has 24 chromosomes in its hair cells.

The number of chromosomes in its skin cells is

The number of chromosomes in its sperm cells is

At which stage in the life-history of the mosquito is control easiest?

Which of the following diseases is caused by the malfunctioning of the pancreas?

Which of the following is true of antigens?

They are produced by white blood cells.

They cause the production of antibodies.

They get rid of antibodies.

They are used to treat diseases.

Immunization is MOST effective in controlling the spread of a communicable disease if

a vaccine is administered to an uninfected individual

serum is administered to an uninfected individual

a vaccine is administered to an infected individual

serum is administered to an infected individual

Items 55-56 refer to the information below.

A student found on the school's playing field a rotting log on which she could identify woodlice, ants and mushrooms. She made the following list. 1. Rotting log II. Ants III. Woodlice IV. Mushrooms V. Playing field

The community consists of

Which ofthe following did the student observe?

A population of woodlice in the playing field environment

A population of woodlice in the playing field habitat

A community of woodlice in the playing field habitat

A community of woodlice in the playing field environment

While studying the feeding relationships of organisms in the backyard of the school, students carried out the following activities.

I. Collected one specimen only on each species for further observation. II. Returned all organisms, alive, to the backyard. III. Moved the rocks and logs and placed them in one heap.

Which of these activities represent good ecological practice?

What would be the BEST method of investigating the range of organisms found between the low tide mark and the high tide mark on a sloping, rocky sea shore?

Using a line transect

Collecting as many species as possible

Using large quadrats

Taking a complete census of the area

Which of the following are reasons to return glass bottles?

Which of the following is NOT an air pollutant?

CSEC Biology Paper 1 May/June 2006 - Free CXC Past Paper with Answers

CSEC Biology Paper 1 May/June 2006 Questions