How well do you understand living things and their vital processes? Whether you are preparing for JAMB, WAEC, NECO and Post-UTME, these Biology past questions and answers cover such subjects as the chemistry of life, botany, evolution, genetics, ecology etc to help you know what to expect, improve your speed and confidence and be really prepared for the actual aptitude test.
Size, colour and fingerprints are examples of ______
physiological variation
discontinuous variation
morphological variation
adaptive variation
Correct answer is C
Morphological variation includes aspects of the outward appearance i.e shape, structure, color, pattern, size which is in contrast to physiology variation which deals primarily with function.
Morphological variation arises from a number of factors which can be bluntly classified as either genetic or environmental implanted into the process of evolution.
Nitrogen is released into the atmosphere when ________
plants absorbs mineral salt
sugar is completely broken down
through plant uptake
when lightning strike
Correct answer is D
Nitrogen is essential to all living systems, which makes the nitrogen cycle one of Earth's most important nutrient cycles.
Atmospheric nitrogen becomes part of living organisms in two ways. The first is through bacteria in the soil that form nitrates out of nitrogen in the air. The second is through lightning. During electrical storms, large amounts of nitrogen are oxidized and united with water to produce an acid that falls to Earth in rainfall and deposits nitrates in the soil.
The feeding relationship among a set of members of a community is referred to as _______?
a food web
pyramid of energy
a food chain
pyramid of number
Correct answer is C
Feeding relationships between organisms in a community are represented by food chains, which show the sequence in which organisms feed on each other. The chain generally begins with an autotroph such as a green plant (e.g. stinging nettle ---> small tortoiseshell butterfly caterpillar --> house sparrow --> sparrowhawk), or with dead organic matter (detritus) (e.g. leaf litter --> earthworm --> young blackbird --> fox). The arrows indicate the passage of food, and therefore energy flow, from one organism to another.
Pyramids of energy are the most accurate representation of feeding relationships in a community, providing information about the amount of energy flowing through each trophic level over a set period of time.
Food web involve many complex feeding relationship and most most ecosystems are more complex than food chain.
Which of the following choices correctly describes the composition of the cell membrane?
contains only lipids
contains lipids and protein
contains lipids and cytosol
contains only proteins
Correct answer is B
It consists of a lipid bi-layer with embedded proteins. The basic function of the cell membrane is to protect the cell from its surroundings.
The cell membrane controls the movement of substances in and out of cells and organelles. In this way, it is selectively permeable to ions and organic molecules.
Coloration of the eye is ______ variation
physiological
morphological
adaptive
recessive
Correct answer is B
Eye coloration is a caused by morphological variation.