2017 - JAMB Biology Past Questions and Answers - page 2

Adaptation is process by which an animal or plant species becomes fitted to its environment; it is the result of natural selection’s acting upon heritable variation. Even the simpler organisms must be adapted in a great variety of ways: in their structure, physiology, and genetics, in their locomotion or dispersal, in their means of defense and attack, in their reproduction and development, and in other respects.


Evolution explains how living things change over a long time, and how they have come to be the way they are
Variation is any difference between cells, individual organisms, or groups of organisms of any species caused either by genetic differences (genotypic variation) or by the effect of environmental factors on the expression of the genetic potentials (phenotypic variation). Variation may be shown in physical appearance, metabolism, fertility, mode of reproduction, behaviour, learning and mental ability.

Succession is the process by which the structure of a biological community evolves over time. Two different types of succession—primary and secondary—have been distinguished. Primary succession occurs in essentially lifeless areas—regions in which the soil is incapable of sustaining life as a result of such factors as lava flows, newly formed sand dunes, or rocks left from a retreating glacier.

Secondary succession occurs in areas where a community that previously existed has been removed; it is typified by smaller-scale disturbances that do not eliminate all life and nutrients from the environment.

Wind vane is an instrument for showing the direction of the wind.

A coccus (plural cocci) is any bacterium that has a spherical, ovoid, or generally round shape. A bacillus is any bacterium that has a rod shape.

Vibrio is bacteria possessing a curved-rod shape

Diplobacillus is a rod-shaped bacterium occurring in pairs linked end to end.

A flame cell is a specialized excretory cell found in the simplest freshwater invertebrates, including flatworms (fluke, planaria)

Flame cells function like a kidney, removing waste materials.
Excretion of ammonia waste through the body wall, and is not associated with any specific organs

Food chain refers to the sequence of transfers of matter and energy in the form of food from organism to organism. Food chains intertwine locally into a food web because most organisms consume more than one type of animal or plant. Plants, which convert solar energy to food by photosynthesis, are the primary food source. In a predator chain, a plant-eating animal is eaten by a flesh-eating animal. In a parasite chain, a smaller organism consumes part of a larger host and may itself be parasitized by even smaller organisms.

In a saprophytic chain, microorganisms live on dead organic matter.

It is transmitted to pig through human feaces or contaminated vegetation contaminated with human excreta.

A superior ovary is an ovary attached to the receptacle above the attachment of other floral parts
A half-inferior ovary is embedded or surrounded by the receptacle.

An inferior ovary lies below the attachment of other floral parts.

Parasitic nutrition is heterotrophic nutrition where a parasitic organism lives on the body surface or inside the body of another type of organism (a host) and gets nutrition directly from the body of the host. Since these parasites derive nourishment from their host, this symbiotic interaction is often described as harmful to the host.
Saprotrophic nutrition is a process of chemoheterotrophic extracellular digestion involved in the processing of decayed organic matter.

The organism feeds on dead matter i.e fungi
A carnivore is an organism that derives its energy and nutrient requirements from a diet consisting mainly or exclusively of animal tissue, whether through predation or scavenging

Volvox is an example of organism thatforms spherical colonies of up to 50,000 cells.
A colony is composed of two or more individuals living in close association with, or connected to, one another, usually for mutual benefit such as stronger defense or the ability to attack bigger prey.

It is a cluster of identical cells (clones) on the surface of (or within) a solid medium, usually derived from a single parent cell.