Biology Past Questions And Answers
The depletion of the ozone layer will result in the earth surface receiving more
- A. gamma rays
- B. infra-red rays
- C. ultraviolet rays
- D. X-rays
Higher organisms use a transport system and not diffusion only to distribute nutrients because
- A. the ratio of their surface area to volume is small
- B. metabolic waste products diffuse to the surface of the organisms
- C. the rate at which nutrients and other substances diffuse increases
- D. substances to be transported move shorter distances to reach the numerous cells
Which of the following blood components has the greatest affinity for oxygen and carbon (IV) oxide?
- A. Lymphocyte
- B. Thrombocyte
- C. Erythrocyte
- D. Blood plasma
One advantage of variation in a species population is that individuals
- A. with favoured traits become dominant
- B. easily reach their reproductive age
- C. are easily recognised by mates
- D. are better adapted to change
The two key cations involved in the action potential of nervous transmissions are?
- A. Na^+ and Fe^2+
- B. Mg^2+ and K^+
- C. Na^+ and K^+
- D. Fe^2+ and Mg^2+
Use the list of insects below to answer the question below;
I. Cotton stainer II. Honeybee III. Termite IV. Weevil
The insects whose activities are both beneficial and harmful to humans are;
- A. I and II
- B. II and III
- C. II and IV
- D. III and IV
The mammalian organ which acts both as a digestive and as an endocrine organ is the
- A. oesophagus
- B. liver
- C. pancreas
- D. spleen
The table below shows the number of some organisms in habitats W and Y. Study it to answer the question below;
| Organism | Number in the habitat | |
| habitat W | habitat Y | |
| Plankton | 126 | 0 |
| Antelope | 0 | 51 |
| Water flea | 10 | 0 |
| Tilapia | 23 | 0 |
| Lion | 0 | 6 |
| Frog | 6 | 0 |
| Grass | 0 | 250 |
The number of lions and antelops in habitat Y shows that the lion
- A. is the prey while the antelope is the predator
- B. is the predator while the antelope is the prey
- C. and the antelope are preys to each other
- D. and the antelopes are predators
sources of air pollutants are?
- A. industrial chimneys, burning fossil oils and river dams
- B. sulphurdioxide, acid rain and pesticides
- C. sulphur dioxide, vehicle exhausts, and aerosols
- D. sewage,smoke and old vehicles
The carnassial teeth of a carnivorous animal consist of the
- A. last upper premolar and the first lower molar
- B. last upper molar and the last lower molar
- C. first upper premolar and the lower molar
- D. first upper molar and the first lower molar