Which of these processes removes carbon from the atmosphere?

• A. Putrefaction of animals
• B. Burning of fuels
• C. Photosynthesis
• D. Volcanic eruption

Which of these is not applicable to the circulation of water- in nature?

• A. Water removed from oceans are Permanently lost
• B. Water constantly evaporates from the seas, rivers, lakes and soil
• C. Water vapour rises. cools, condenses and precipitates as rain and dew
• D. Water is absorbed by plants and animals from their external environment

Which of the following conditions is not necessary for photosynthesis to occur in plants?

• A. There must be light
• B. There must be xylem tissue used to conduct water
• C. There must be chlorophyll to trap radiant energy
• D. Carbondioxide must be present

Which of the following is the correct chain for the organism found in an aquatic community?

• A. Paramecium, Phytoplankton, Prawn, Waterflea, Tilapia, Shark
• B. Waterflea, Paramecium, Phytoplankton, Prawn, Tilapia, Shark
• C. Phytoplankton, Waterflea, Paramecium, Prawn, Shark, `tilapia
• D. Phytoplankton, Paramecium, Waterflea, Prawn, Tilapia, Shark

Which of these could be regarded as an advantage of complexity in higher organisms?

• A. there is no cellular differentiation
• B. Cellular differentiation leads to loss of independence of the cells
• C. Complexity stops at cellular differentiation only
• D. Cellular differentiation leads to internal structural specialization

The distribution of organisms in a fresh - water habitat like a stream or pond is determined by the following except

• A. rainfall
• B. temperature
• C. pH of soil
• D. light penetration

(a) With reference to the food chain, explain the role of the followings; (i) green plants; (ii) herbivores; (iii) carnivores; (iv) decomposers

(b) With the aid of diagram, describe the carbon cycle.

Very low annual rainfall, sparse vegetation, high day temperatures and cold nights are the characteristics of the biome known as

• A. swamp
• B. tropical forest
• C. southern guinea savanna
• D. desert

Which of the following statements is not correct?

• A. Shortage of food may be caused by pestilence, rinderpest and neglect of farming
• B. Shortage of food may lead to competition, emigration, death and decline in the rate of reproduction
• C. Over-crowding may lead to scarcity of food
• D. Territorial defence encourages food scarcity in a habitat

In complex food relationships in a community, the primary, secondary and tertiary consumers are referred to as

• A. symbionts
• B. omnivores
• C. heterotrophs
• D. autotrophs