The part labelled X is the
- A. axon
- B. cell body
- C. terminal dendrites
- D. synapse
The diagram represents
- A. sensory neurone
- B. relay neurone
- C. afferent neurone
- D. motor neurone
From which group of animals are the mammals generally believed to have most recently evolved?
- A. Reptiles
- B. Fish
- C. Amphibians
- D. Birds
The least evidence in support of the theory of evolution is provided by the study of
- A. anatomy
- B. ecology
- C. geology
- D. embryology
The colour of the ventral surface of a fish is lighter than that of the dorsal. This is mainly
- A. an adaptation for movement
- B. an adaptation for camouflage
- C. for attracting mates
- D. for regulating body temperature
Scales on reptiles are a feature for
- A. conserving water
- B. conserving food
- C. protecting the skin
- D. locomotion
The slender, long and slightly curved beak of the sun-bird is an adaptation for breeding for feeding on
- A. nectar
- B. small seeds
- C. big seeds
- D. insects
All the sons of a colour-blind woman will be coloured blind regardless of the state of the father because
- A. the egg determines the phenotype of the son
- B. sons inherit the sex chromosome of their mothers
- C. the father's sex chromosomes is weaker in sons
- D. sex-linked traits express dominance in females
The F1 of a cross between a tall and a dwarf plant was tall. The F1 was advanced to F2. How many of 120F2 plants will be dwarf?
- A. 30
- B. 60
- C. 90
- D. 120
A man with blood group a is married to a woman with blood group A. Which of the following group combinations is possible if the family has three children?
- A. B, A, AB
- B. O, A, B
- C. B, AB, AB
- D. A, O, A
The specific number of chromosomes in each somatic cell is represented by
- A. 2N
- B. 23
- C. 2N
- D. N
The DNA molecule is a chain of repeating
- A. nucleosides
- B. nitrogenous bases
- C. sugar phosphates
- D. nucleotides
A person with type O blood can donate to a patient with type A because the donor’s blood
- A. lacks antigens
- B. lacks anti-A antibodies
- C. lacks anti-B antibodies
- D. has both anti-A and anti-B antibodies
Human height is an example of a feature which depends on both
- A. genotype and phenotype
- B. genetic and environmental factors
- C. mother's genotype and environmental factor
- D. phenotipic and environmental factors
Environmental pollutants which can work through the media of water, soil and air include
- A. carbon monoxide
- B. noise
- C. sulphur(IV)oxide
- D. smoke
Some of the diseases caused by bacteria are
- A. tuberculosis, gonorrhoea and syphilis
- B. tuberculosis, gonorrhoea and AIDS
- C. Poliomyelitis, syphilis and gonorrhoea
- D. AIDS, cholera and tuberculosis
Which of the following is a measure for the control of bilharzia?
- A. Cutting low brushes around homes
- B. Application of molluscicides in water bodies
- C. Screening windows and doors with mosquito nets
- D. Application of herbicides in water bodies
Colonization of a bare rock surface is termed
- A. evolution
- B. specification
- C. primary succession
- D. secondary succession
In a tropical rain forest, non-epiphytic ferns and allies occur as
- A. middle storey species
- B. upper storey species
- C. shade-loving species
- D. emergent species
In spite of the removal of carbondioxide from the atmosphere, its amount remains more or less constant because
- A. it is produced by green plants during photosynthesis
- B. it is produced during respiration of animals
- C. it is absorbed inn ocean water
- D. green plants release it during the day
In a food chain involving a primary producer, a primary consumer as well as a secondary consumer, the sharing of trophic energy is in the form that the
- A. the primary consumer has more energy than the primary poducer
- B. secondary consumer takes up all the energy contents of the primary consumer
- C. energy is shared equally between the three groups of organism
- D. secondary consumer gets only a small portion of the energy contained in the primary producer