NEET Practice Questions (MCQs) with Answers & Solutions

August Weismann conducted experiments where he cut off the tails of mice for several generations to disprove Lamarck's theory of inheritance of acquired characteristics. Weismann showed that the acquired trait (loss of tail) was not passed on to the offspring, thus supporting the idea that genetic information is not influenced by changes in the body during an organism's life.

Human beings belong to the species Homo sapiens. This is the current scientific classification and it distinguishes modern humans from other species in the genus Homo, such as Homo erectus and Homo habilis.

Fossils provide crucial evidence for understanding evolutionary relationships because they are the preserved remains or traces of organisms from the past, allowing scientists to trace changes over time.

Factors like inherited genetic differences, health, and age can all contribute to variation within a population. Therefore, 'None of the above' is the correct answer.

Differences due to diet, health, age, or accident do not affect an individual's ability to survive and reproduce, and hence, are not important from an evolutionary standpoint. Evolutionary importance is linked to genetic variations that influence reproductive success.

Genetic variation is crucial because it ensures that not all organisms are susceptible to the same threats, allows for evolutionary adaptations over time, and drives changes in gene frequencies within populations. Thus, all given statements highlight the importance of genetic variation from an evolutionary perspective.

Genetic variation refers to differences in DNA among individuals. Eye color is determined by genetic differences, making it a clear example of genetic variation. In contrast, age, scars, or diet preferences are not determined by genetic factors.

Environmental variation refers to differences caused by environmental factors rather than genetic inheritance. In this case, Marge dyeing her hair blue is an example of environmental variation because it is influenced by her personal choice and environmental factors, not by her genes.

Genetic drift is a mechanism of evolution that involves random changes in the frequency of alleles in a population. It does not involve competition between members of a species, unlike natural selection which is driven by differential survival and reproduction based on advantageous traits.