Biology 2014 JAMB Past Questions - Question 49: All living organisms are constantly involved in a struggle for existence. This was proposed by

Correct Answer

B

Explanation

The theory of evolution through natural selection was first proposed by Charles Darwin. This theory states that living organisms reproduce very fast when the environment is favorable. This leads to competition (struggle for existence)and selection of the fittest by nature. After some years, Alfred Wallace proposed the same theory of evolution of species by natural selection which coincided with that of Darwin. Charles Darwin presented both theories (his own and that of Wallace) to the world of science. (Linnaean study) in 1858. Morgan was noted for u s i n g fr u i t f l y ( D r o s o p h i l i amelanoqastert to study genetics because this, fly had three advantages namely (I) It breeds large number of offspring within a short period (10days)so that geneticists could watch several generations of fruit flies within one year. (ii) It has only four pairs of clearly distinguishable cliiumosomes in each cell.(iii) It has small size and lots of them can be enclosed in a small container. Morgan developed chromosome mappings i.e. the exact position of genes on the chromosomes called gene loci. Lamarck proposed a theory on evolution (Lamarckism) which explained how changes in a species of organisms take place overtime. His theory is base on use and disuse of body parts and inheritance of acquired traits.