Which of the following structural features are adapted for uses other than water conservation?
- A. Succulent stems
- B. Scales in animals
- C. Spines in plants
- D. Feathers in birds
Complex social behaviour and organization are found mostly in
- A. insects
- B. birds
- C. reptiles
- D. mammals
A certain savanna grasshopper changes colour from green during the rainy season to brown during the dry season and black after dry season bush fires. The reason for these colour changes is that the
- A. grasshopper is getting older
- B. environmental temperature is changing
- C. grasshopper is avoiding predation
- D. grasshopper is frequently moulting
The mutation theory of organic evolution was propounded by
- A. Gregor Mendel
- B. Hugo de Vries
- C. Jean Lamarck
- D. Charles Darwin
Example of water-borne and sex linked diseases are?
- A. taeniasis and malaria
- B. cholera and gonorrhoea
- C. typhoid and syphilis
- D. dracunculiasis and haemophilia
In a group of male Agama lizards, the one with the brightest head colour is the
- A. dominant
- B. youngest
- C. oldest
- D. largest
The older fossil-bearing rocks, in contrast to the more recent ones, are more likely to contain?
- A. animal rather than plant remains
- B. invertebrates rather than birds
- C. flowering plants rather than mosses
- D. reptiles rather than fishes
Blood grouping in human beings is derived from combinations of
- A. two different alleles
- B. four different alleles
- C. three different alleles
- D. two different genes
The surest way to combine the best qualities of both parents in the offspring is by
- A. cross-breeding
- B. inbreeding
- C. selective breeding
- D. pure breeding
The pollutants that contribute to the depletion of the ozone layer in the atmosphere are
- A. radioactive materials
- B. oxides of sulphur
- C. oxides of carbon
- D. chlorofluorocarbons
A cross between an albino female and a genetically normal male will result in offspring that are
- A. all albino
- B. all phenotypically normal
- C. all genetically normal
- D. half albino and half normal
The factors that determine the distribution of vegetation zones are
- A. temperature, light, rain and humidity
- B. light, humidity, air and mist
- C. temperature, light, air and humidity
- D. humidity, snow, frost and dew
The legs and beak of an egret resemble those of the heron because they
- A. both feed on fishes
- B. are both birds
- C. occupy similar niche
- D. occupy the same trophic level
The disaster that would have the least destructive impact on animal life and balance in nature is
- A. chemical pollution
- B. forest fires
- C. oil spillage
- D. grasshopper pests
In a food chain, each succeeding level in a forward direction represents
- A. an increase in the number of individuals
- B. a decrease in the number of individuals
- C. an increase in the biomass of individuals
- D. a gain in the total energy being transferred
Which of the following is an adaptation of tropical rainforest species?
- A. Few stomata
- B. Thick bark
- C. Buttress roots
- D. Reduced leaves
Which of the following are adaptations of animals to aquatic habitats?
- A. Gills, streamlined bodies and lateral lines
- B. Lateral line, streamlined bodies and lungs
- C. Gills, scaly skin and lungs
- D. Gills, streamlined bodies and spiracles
Which of the following growth activities in plants is brought about by gibberellins?
- A. Rapid cell division
- B. Tropic response
- C. Cell elongation
- D. Main cell elongation
The range at which soil essential elements concentration is recorded for optimal plant growth is marked
- A. IV
- B. III
- C. II
- D. I
The soil becomes toxic to plants when the concentration of its essential elements is in the range labelled
- A. IV
- B. III
- C. II
- D. I
I. High birth rate and high immigration rate II. Low birth rate and high immigration rate III. Low mortality rate and low emigration IV. High mortality rate and high emigration rate. Which combination of the above can cause rapid over-crowding in climax biotic communities and human settlements?
- A. II and III
- B. I and III
- C. I and IV
- D. I and II