2021 - JAMB Biology Past Questions and Answers - page 4

Stomata allow a plant to take in carbon dioxide, which is needed for photosynthesis. They also help to reduce water loss.

The alveoli are where the lungs and the blood exchange oxygen and carbon dioxide during the process of breathing in and breathing out.

The Malpighian tubules are tubular structures that are free floating in the haemolymph and function as excretory and osmoregulatory organs of insects. 

 Contractile vacuoles (in the cells of the lower organisms) protect a cell from absorbing too much water and potentially exploding by excreting excess water.

Fish exchange gases by pulling oxygen-rich water through their mouths and pumping it over their gills. In some fish, capillary blood flows in the opposite direction to the water, causing counter-current exchange. The gills push the oxygen-poor water out through openings in the sides(opercula) of the pharynx.

People with type AB+ blood are universal recipients because they have no antibodies to A, B or Rh in their blood and can receive red blood cells from a donor of any blood type.

 Donors with blood type AB can donate to recipients with blood type AB only.

Plants that live in water and adapt to their environment are known as hydrophytes.

Epiphyte, also called air plant, any plant that grows upon another plant or object merely for physical support.

 Plants that grow in dry habitat are called xerophytes.

Mesophytes are terrestrial plants which are neither adapted to particularly dry nor particularly wet environments.

The phylum Arthropoda is the largest in the animal kingdom, having its class Insecta as 70% of all known species of animals.

Taxism: oriented movement of a motile organism in response to an external stimulus, as toward or away from light.

A tropism is a biological phenomenon, indicating growth or turning movement of a biological organism, usually a plant, in response to an environmental stimulus.

 In tropisms, this response is dependent on the direction of the stimulus.

The movement or directional growth of plants or plant organs (as the tendrils of climbing plants) in response to the stimulus of touch.

The non-directional movement (of plants) in response to a stimulus (e.g. humidity, temperature, light irradiance, nutrients, gravity, etc.

Gregor Mendel, through his work on pea plants, discovered the fundamental laws of inheritance. 

 Hugo de Vries (1901) put forward a theory of evolution, called mutation theory. 

Jean Baptiste Lamarck believed that traits changed or acquired over an individual's lifetime could be passed down to its offspring.

The Theory of Evolution by natural selection was first formulated in Charles Darwin's book "On the Origin of Species" published in 1859.

It is called a double circulatory system because blood passes through the heart twice per circuit.