50 questions. Try each one, then open the answer to check yourself and read the explanation.
In Spirogyra, the pyrenoid
Answer: D (usually contains starch)
Pyrenoids are small bodies on the spiral chloroplast of Spirogyra where starch is formed and stored.
In which of the following groups of animals are flagella and cilia found?
Answer: D (Protozoa)
Many protozoa move with flagella (e.g. Euglena) or cilia (e.g. Paramecium).
Which of the following is seed bearing?
Answer: B (Whistling pine)
The whistling pine (Casuarina) is a seed plant. Mosses, algae, liverworts and ferns reproduce by spores.
Each of the following is an arthropod EXCEPT the
Answer: C (snail)
The snail is a mollusc with a soft body and a shell, not jointed legs.
In fish the sense organs which detect movements in the water are located within the
Answer: E (lateral line)
The lateral line along each side of the fish contains sense organs that detect vibrations and water movements.
Euglena is an autotrophic organism because it
Answer: D (can manufacture its food)
Autotrophic means 'self-feeding': Euglena has chloroplasts and makes its own food by photosynthesis.
Which of the following is NOT true of Mucor? It
Answer: A (contains chlorophyll)
Mucor is a fungus, so it has no chlorophyll and feeds saprophytically on dead matter.
Bryophytes are different from flower because they
Answer: E (have no vascular tissues.)
Bryophytes (mosses and liverworts) have no xylem or phloem, while flowering plants have vascular tissues.
At what stage in the life history of a toad is its mode of breathing similar to that of a fish?
Answer: D (Internal gill stage)
Fish breathe with internal gills covered by an operculum. The older tadpole has internal gills covered by a fold of skin and pumps water over them in the same way.
In lower plants like mosses, the structure which performs the functions of roots of higher plants is called
Answer: D (rhizoids)
Mosses have no true roots; thin threads called rhizoids anchor them and absorb water.
In an angiosperm leaf, the xylem is
Answer: C (above the phloem)
In the veins of a leaf, xylem and phloem share each vascular bundle. The xylem lies on the upper side and the phloem on the lower side.
A group of similar cells performing the same function is
Answer: C (a tissue)
A tissue is a group of similar cells working together, e.g. muscle tissue. Several tissues make an organ.
Which of the following is common to a dicotyledonous stem and a monocotyledonous root?
Answer: B (Central pith)
Both the dicot stem and the monocot root have a central pith of parenchyma; the dicot root usually has none.
Which of the following represents the sequence of protein hydrolysis? 1. Polypeptides 2 Amino acids 3. Proteins 4. Peptones
Answer: D (3 → 4 → 1 → 2)
Proteins are broken into peptones, then into shorter polypeptides, and finally into amino acids.
A food substance which produces red colouration with Sudan III contains
Answer: E (fat.)
Sudan III is a red dye that dissolves in fats and oils, so a red colour shows fat is present.
If calcium is deficient in food this may cause
Answer: B (retarded growth)
Calcium is needed to build bones and teeth, so lack of it gives weak bones (rickets) and poor growth. Anaemia is from lack of iron and goitre from lack of iodine.
Partially digested food ready to leave the stomach is referred to as
Answer: A (chyme)
Food churned with gastric juice in the stomach becomes a creamy liquid called chyme, which passes into the duodenum.
The function of lymph nodes is to
Answer: B (filter out bacteria)
Lymph nodes filter the lymph, and their white blood cells trap and destroy bacteria.
The vein which returns blood from the head and arms to the heart is called
Answer: C (superior vena cava)
The superior (anterior) vena cava brings blood from the head and arms; the inferior vena cava brings it from the lower body.
Blood platelets are important because they
Answer: E (release thrombin for blood clotting.)
Platelets start blood clotting at a wound by releasing the substance that leads to thrombin being formed. Antibodies and antitoxins come from white cells.
If a child can receive blood from all donors, he belongs to the blood group
Answer: D (AB)
Group AB blood has no anti-A or anti-B antibodies in its plasma, so it does not clump donor cells of any group. AB is the universal recipient.
Which of the following events does NOT occur during anaerobic respiration of glucose?
Answer: D (Energy is not produced)
Anaerobic respiration still releases energy, though much less than aerobic respiration, so 'energy is not produced' is false.
Identify which of the following are characteristics of the vertebrate respiratory surface. 1. Moist 2. Vascularized 3. Semipermeable 4 Freely permeable 5. Dry
Answer: A (1,2,3)
Gases must dissolve in water before they can diffuse, so respiratory surfaces are moist. They are also thin and permeable, and well supplied with blood vessels to carry the gases away.
In mammals, the function of the sebaceous gland is to
Answer: D (produce an oily substance)
Sebaceous glands open into hair follicles and secrete sebum, an oily substance that keeps skin and hair soft and waterproof.
Which of the following organs regulates the amount of amino acids and glucose in the body?
Answer: B (Liver)
The liver stores excess glucose as glycogen and breaks down excess amino acids (deamination), keeping their blood levels steady.
Use the diagram (Fig. 1, a section of a mammalian kidney) to answer this question. Bowman's capsules are located in the part labelled
Answer: B (2)
The Bowman's capsules (with their glomeruli) lie in the cortex, the outer layer of the kidney, labelled 2.
Use the diagram (Fig. 1, a section of a mammalian kidney) to answer this question. Reabsorption of useful materials takes place in the parts labelled
Answer: E (2 and 4.)
Useful substances are taken back into the blood from the kidney tubules, which run through the cortex (2) and down into the inner region (4); 1 is the capsule and 5, 7 and 8 are tubes and vessels.
Movements and positions of the head in man are detected by the
Answer: D (semicircular canals)
The fluid in the semicircular canals moves when the head turns, stimulating sense cells that detect the movement and help keep balance.
The appendicular skeleton is made up of the
Answer: E (girdles and limbs.)
The appendicular skeleton is the bones of the limbs together with the pectoral and pelvic girdles that join them to the axial skeleton.
The maize grain is a fruit and not a seed because it
Answer: B (is formed from an ovary)
A fruit develops from an ovary. The maize grain is a whole ovary whose wall (pericarp) is fused to the seed coat.
If a flower is protandrous then it
Answer: E (can prevent self-pollination.)
In a protandrous flower the anthers ripen before the stigma, so its own pollen is usually shed before the stigma can receive it. This prevents self-pollination.
For pollen to be released in Crotalaria the insect must depress the
Answer: B (keel)
In Crotalaria the stamens and stigma are hidden inside the keel petals. When an insect lands and presses the keel down, the pollen is pushed out onto it.
Irish potato is a
Answer: E (stem tuber.)
Irish potato tubers form at the tips of underground stems and carry buds (eyes) that sprout into new shoots, which shows they are stem tubers.
The characters by which an organism is recognized are termed its
Answer: A (phenotype)
The phenotype is the set of visible (observable) characters of an organism. The genotype is its genetic make-up.
The hereditary material in a cell is known as
Answer: E (DNA.)
DNA (deoxyribonucleic acid) in the chromosomes carries the genes passed from parents to offspring.
A young plant showing yellow leaves is likely to be deficient in
Answer: B (magnesium)
Magnesium is part of the chlorophyll molecule, so without it leaves cannot make chlorophyll and turn yellow (chlorosis).
Germination which results in the cotyledons being brought above ground is called
Answer: C (epigeal)
In epigeal germination (e.g. bean) the hypocotyl grows and lifts the cotyledons above the soil. In hypogeal germination they stay below.
The mammalian endocrine system is responsible for
Answer: D (chemical co-ordination)
Endocrine glands release hormones into the blood, which coordinate body activities chemically. Nerves transmit impulses.
An old man is likely to be long-sighted because age affects the
Answer: C (ciliary muscles)
With age the ciliary muscles weaken and the lens loses its elasticity, so the eye cannot thicken the lens to focus on near objects (long-sightedness).
In a mammal, stimulus is transferred from the receptor muscle to the central nervous system through the
Answer: D (sensory neurons)
Sensory neurons carry impulses from receptors to the brain or spinal cord. Motor neurons carry them out to the effectors.
A relationship between living organisms which is of mutual benefit is
Answer: D (symbiosis)
In symbiosis (mutualism) both partners gain, e.g. legumes and their nitrogen-fixing bacteria. In commensalism only one gains.
Which of the following food chains is in the correct sequence?
Answer: A (Weeds → Tadpoles → Beetles → Fish → Man)
A food chain starts with the producer (weeds), eaten by tadpoles. Water beetles eat tadpoles, fish eat the beetles and man eats the fish.
The primary and secondary hosts respectively of bilharzia are
Answer: D (man and snail)
The adult Schistosoma lives and breeds in man (primary host); its larvae develop in the water snail (secondary host).
Which of the following is NOT caused by bacteria?
Answer: D (Onchocerciasis)
Onchocerciasis (river blindness) is caused by a filarial worm, Onchocerca volvulus. Cholera, gonorrhoea, tuberculosis and typhoid are bacterial diseases.
Tsetse fly is harmful to man because it is associated with the spread of
Answer: C (sleeping sickness)
The tsetse fly carries Trypanosoma, which causes sleeping sickness. River blindness is spread by blackflies and malaria by mosquitoes.
Soil erosion CANNOT be controlled by
Answer: E (burning of bush.)
Burning bush removes the plant cover that protects the soil, so it increases erosion. The others all protect the soil.
Water retention is highest in soils which are rich in
Answer: C (clay and humus, but poor in sand)
Clay particles have tiny spaces that hold water, and humus soaks up water like a sponge. Sand drains quickly, so a soil rich in clay and humus but poor in sand holds the most water.
The origin of mineral particles in the soil is
Answer: D (weathered rock)
Sand, silt and clay particles are formed when rocks are broken down by weathering. Organic matter forms humus.
Atmospheric nitrogen is directly replenished in nature through
Answer: A (the activities of denitrifying bacteria)
Denitrifying bacteria break down nitrates in the soil and release free nitrogen gas, which goes back into the atmosphere.
The initial volume of water poured into a bag of dry soil was 50ml and the amount that drained through was 35ml. The percentage water content of the fully soaked soil is therefore
Answer: D (30.0)
Water held by the soil = 50 − 35 = 15 ml. As a percentage of the water added: 15/50 × 100 = 30.0%.