Items 4-5 refer to the following food web. <img src="food_web.png">
4.
How many food chains are there in the food web shown above?
- (A)
2
- (B)
3
- (C)
4
- (D)
5
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CSEC Biology Paper 1 May/June 2018 - Free CXC Past Paper with Answers
Free CXC Biology Paper 1 May/June 2018 past paper from 2018. Includes a worked answer key. Open the PDF, take a timed test, and study with AI on Caribbean AI.
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Which of the following features is used to classify a group of organisms as Class Insecta?
Size
Shape
Colour
Number of segments
Which of the following sampling methods is MOST suitable for estimating the density of mushrooms in a garden?
Quadrat
Line transect
Belt transect
Mark/Release/Recapture
Living organisms, such as plants, are affected by abiotic factors which determine where they become established. Which of the following options lists some of these determining factors?
Sediment size, shape and colour
Sunlight availability, soil pH, minerals
Parasitism, commensalism, mutualism
Deforestation, slash and burn, shifting cultivation
Items 4-5 refer to the following food web. <img src="food_web.png">
How many food chains are there in the food web shown above?
2
3
4
5
Which of the following statements describes the relationship where the ocelot eats an iguana and the iguana eats plants?
Both the iguana and the ocelot are prey.
Both the ocelot and the iguana are predators.
The ocelot is the predator while the iguana is the prey.
The ocelot is the prey while the iguana is the predator.
Item 6 refers to the following food web.
Trophic level 1 is represented by
phytoplankton
zooplankton
marine mammals
small fish and crustaceans
Approximately 10% of the energy stored in food is available to the next organism in a food chain because
most of the energy is lost as heat during the process of respiration
most of the energy is lost during the process of excretion
there are fewer consumers than producers in a food chain
many consumers compete for the same food source
Which of the following materials is considered to be non-biodegradable?
Grass cutting
Sardine can
Newspaper
Cloth
Which of the following statements BEST explains why the coral reefs in the Caribbean are at risk?
There has been overfishing of the seas.
The Caribbean is a popular tourist destination.
There have been many hurricanes in the Caribbean.
There has been an increase in the volume of sewage flowing into the reefs.
Replanting trees on a bare hillside is an example of
restoration and preservation
preservation and conservation
reafforestation and restoration
conservation and afforestation
Phase 4 of the graph of population growth is MOST likely due to
disease resistance
a high natural birth rate
adequate food and space
competition from invasive species
When compared to a cheek cell, a muscle cell contains more
vacuoles
ribosomes
mitochondria
chromosomes
Which of the following options correctly identifies and describes the process occurring above?
Diffusion / Water moving from concentrated to dilute solution
Diffusion / Sugar moving from dilute to concentrated solution
Osmosis / Water moving from dilute to concentrated solution
Osmosis / Sugar moving from concentrated to dilute solution
Which of the following functions is NOT correctly matched to the organelle?
Osmotic control / Membrane
Protein synthesis / Chloroplast
Hereditary materials / Nucleus
Release of energy / Mitochondrion
A mature plant cell is different from a mature animal cell because the plant cell has
mitochondria
a cell membrane
a large permanent vacuole
a nucleus suspended in the cytoplasm
An enzyme is BEST defined as a catalyst which
increases the rate of a chemical reaction
decreases the rate of a chemical reaction
increases the rate of a chemical reaction but remains unchanged at the end of the reaction
decreases the rate of a chemical reaction but remains unchanged at the end of the reaction
Which of the following features does NOT enhance a leaf's ability to absorb solar energy?
Numerous chloroplasts in the palisade cells
Presence of a vascular bundle
Transparent cuticle
Large surface area
The food nutrient produced is
fat
glucose
protein
amino acid
Which of the following organisms is a saprophyte?
Cat
Amoeba
Mango tree
Bread mould
Item 21 refers to the following graph.
Which of the following statements BEST accounts for the shape of the graph of light intensity versus the rate of photosynthesis?
As the rate of photosynthesis increases, there is a decrease in carbon dioxide levels.
As light intensity increases, the rate of photosynthesis also increases, until a stationary phase exists, when denaturation of the enzymes occurs.
As light intensity increases, there is an increase in the rate of photosynthesis, until there is no further increase in the rate due to some other limiting factor.
As carbon dioxide levels gradually increase, there is a similar increase in the rate of photosynthesis, until a plateau phase exists where no further increase in carbon dioxide results in any further increase in photosynthesis.
Item 22 refers to the following diagram of the respiratory system showing strutures in the respiratory system.
Which of the labelled parts represents a rib?
I
II
III
IV
Which of the following conditions is an effect of the nicotine found in cigarette smoke?
Increased heart rate
Increased beating of cilia
Reduced oxygen transport by the blood
Increased mucus production in the cells lining the respiratory passage
Which of the following sequences is the correct order of the steps?
I → II → III → IV
II → III → IV → I
III → IV → I → II
IV → III → I → II
What is the MAIN storage product of plants?
Starch
Sucrose
Glucose
Cellulose
Which of the following options correctly matches the gaseous exchange structures with the organism?
Trachea / Mouth / Stems
Alveoli / Gill filaments / Large leaves
Alveoli / Gill rakers / Young leaves
Trachea / Gill bars / Spongy mesophyll
Why is it difficult to develop a vaccine for the common cold?
Vaccines cannot be developed for viruses.
The antigens on the common cold virus remain the same.
The antigens on the common cold virus change frequently.
Human beings cannot produce antibodies for the common cold.
Which of the following options BEST identify some of the transport substances in animals? I. Amino acids II. Hormones III. Sucrose
I and II only
I and III only
II and III only
I, II and III
An amoeba obtains all the oxygen it needs by diffusion via its cell membrane, while a human needs to have special respiratory surfaces for this purpose. The BEST reason for this difference is that
the amoeba does not require much oxygen
oxygen cannot pass through the skin of a human
a human requires a larger volume of oxygen
a human's surface area to volume ratio is too small for diffusion to be effective
Translocation of sucrose in plants occurs via specialized vessels which
are dead, narrow cells
are abundant in mitochondria
contain sieve pores in their end walls
are thin, hollow tubes of lignin
Under which conditions will the rate of transpiration in plants be HIGHEST?
Sunny and low wind speed
Sunny and high wind speed
Cloudy and low wind speed
Cloudy and high wind speed
Persons who suffer from kidney disease are MOST likely to have
a decreased concentration of glucose in the blood
an increased concentration of glucose in the blood
a decreased concentration of urea in the blood
an increased concentration of urea in the blood
Locomotion is important to animals for I. avoiding predators II. acquiring food and shelter III. reproduction
I and II only
I and III only
II and III only
I, II and III
Which of the labelled parts is responsible for the production of male gametes?
I
II
III
IV
The BEST description for the role of excretion in living organisms is to
produce urine
produce faeces
get rid of toxic waste
get rid of excess water
The role of an effector is to
detect a stimulus
respond to a stimulus
create a nerve impulse
relay a nerve impulse
Which of the following diagrams shows the correct direction in which a nerve impulse passes through a reflex arc?
Which of the following phrases correctly describes trophic movement in plants?
Irreversible, whole or part movement
Reversible, whole or part movement
Irreversible, growth or part movement
Reversible, growth or part movement
Which of the following options BEST describes the terms 'stimulus' and 'response'?
A deliberate provocation of an organism / The movement of an organism
An organism's exposure to sunlight / The growth of the organism away from light
A wave of excitement in an organism / Locomotion of an organism
A detectable change in an organism's environment / An organism's reaction to a stimulus
Item 40 refers to the following diagrams showing an eye's response to a stimulus.
The response is MOST likely brought about by
an increase in the light intensity
a decrease in the light intensity
an object being brought nearer
an object being moved further away
Item 41 refers to the following diagram.
Which of the following options correctly identifies the structures labelled I, II and III?
Receptor / Relay nerve / Effector
Skin / Intermediate nerve / Muscle
Sensory nerve / Spinal nerve / Effector
Receptor / Spinal nerve / Effector
The function of the choroid layer in the eye is to
focus most light rays
prevent internal reflection
maintain the shape of the eyeball
control the amount of light entering the eye
Which of the following is an INCORRECT label for the y-axis?
Length
Mass
Number of leaves
Units of time
Which of the following sequences is the correct order of activities?
I → II → III → IV
II → I → III → IV
IV → I → II → III
IV → III → II → I
Which of the following sequences is the correct order of the processes?
I → II → III
I → III → II
II → I → III
II → III → I
The production of new organisms from one parent only is known as
sexual reproduction
asexual reproduction
mitosis
meiosis
Which of the following forms of birth control is MOST likely to be 100% effective?
Condom
Diaphragm
Tubal ligation
Birth control pill
A vector is defined as an organism that
bites humans
causes diseases
lives on other organisms
transmits disease organisms
Item 49 refers to the following diagrams of flowers from two different types of plants. I II
Which of the following statements is true for the flowers?
I is pollinated by a humming bird; II is pollinated by the wind.
Both are pollinated by a humming bird.
Petals are absent from both I and II.
Both are wind pollinated.
A 60-year-old man has been diagnosed with hypertension as well as diabetes. Which of the following treatments would be MOST effective for the diseases?
Exercising and lowering the intake of salt and refined carbohydrates
Spending more time watching television to relax
Starting a rigorous exercise programme
Taking insulin injections
Which of the following BEST describes a chromosome?
Two forms of the same gene
Structure made up of DNA wrapped around histones
Nucleic acid that contains all genetic information
Part of the DNA which carries genetic information to produce a protein
As a result of mitosis each daughter cell has
a variable number of chromosomes
twice the number of chromosomes as the parent cell
the same number of chromosomes as the parent cell
half the number of chromosomes as the parent cell
Which of the following processes will result in genetically identical offspring?
Cloning
Mutation
Fertilization
Crossing over
A man with blood group A married a woman with blood group B. They had two children, EACH with blood group AB. The alleles A and B are described as being
homozygous
codominant
recessive
dominant
Variation in a population is due to
I and II only
I and III only
II and III only
I, II and III
Which of the following features is NOT a characteristic of meiosis?
Maintenance of the diploid number
Genetic recombination of alleles
Crossing over of chromosomes
Random assortment of genes
Tarzan and Jane, both of whom are heterozygous for blood groups A and B respectively, can have offspring that are likely to be
100% AB
50% A: 50% AB
25% AB: 50% B: 25% O
25% A: 25% B: 25% AB: 25% O
Which of the following descriptions is true about natural and artificial selection?
Occurs in domestic populations / Occurs in natural populations
Involves genetic modification / Largely controlled by the environment
Produces great biological diversity / Produces very different organisms from natural populations
Is a faster process / Is a slower process
A species is BEST defined as a group of organisms that
can interbreed and produce fertile offspring
can interbreed and produce many offspring
are physically similar
cannot interbreed
In which of the stages above can insulin be produced by the bacterium?
I
II
III
IV