Heredity and Evolution Test - 6

Wings of bird and wings of insect both are analogous as both of them perform the same function of flight while structures and origin are different. Feathers of birds originate from their forelimbs, the wings of insects originate from the inner or outer surface of the insect’s body.

The carriers of factor (genes) are chromosomes and transfer hereditary information from one generation to another.

Mendel selected pisum sativum (a pea plant )of his ground to observe the characterstics of progeny produced.

Archaeopteryx had a full set of teeth and three claws on the wing which had been used to grasp prey.

The use and disuse of an organ by an organism leads to acquiring ‘variation’ in the features of that organ’ was proposed by Jean Baptist Lamarck.

Individual efforts during the lifetime of the organisms drive species to adaptation, as they supposedly would acquire adaptive changes and pass them on to offspring i.e.., by selective use and disuse of an organ, organisms acquire or loose certain traits during their lifetime.

Wings of parrot and wings of a housefly perform the function of flying. But the parrot’s wings are originated from the mesoderm and are supported by bones while the housefly’s wings are ectodermal in origin are supported by the chitinous structures.

This statement is correct that chromosomes are bearers of hereditary units or genes and each chromosome carries hundreds or thousands of genes.

Branch of study which deals with the fossils is called as paleontology.

It deals with the study of the life of past geological periods as known from fossil remains.

Variations that result from factors such as climate, food supply and actions of other organisms are called as somatic (phenotypic) variations. These variations are not due to differences in genes or chromosomes, and in general are not transmitted future generations. They do not have any significance in the process of evolution.

Sex chromosomes that possess the gene for maleness and femaleness in humans.

In humans the sex chromosomes comprise one pair of the total of 23 pairs of chromosomes. The other 22 pairs of chromosomes are called autosomes.

Individuals having two X chromosomes (XX) are females; individuals having one X chromosome and one Y chromosome (XY) are males.