Question

21. What is inaccurate or misleading about the following statement: individuals adapt to their environment and pass the adaptation to their offspring?

22. Your nerve cells and skin cells contain the same genes. Explain why these cells are different.

23. Explain why sex-linked disorders on the X chromosome are more common in males than females.

Answer 1

Ans 21. The statement follows that individuals adapt to their environment and pass tha adaptation to their offsprings, but traits passes on only when it is beneficial to whole population. An individual adapted to environment won't pass the trait but the trait should be expressed in whole population to be passed on. Adaptations achieved by populations only passes on to the next generation, but not those that are achieved by single individual.

Ans 22. Nerve cells and skin cells contains the same genes, but these cells are different. It depends on gene expression. The particular combination of genes that are turned on and turned off dictates the cellular function and morphology. This gene expression is regulated by both internal and external factors.

Ans 23. Sex-linked disorders on X-chromosomes are more common in males than in females because males contains only one X-chromosome, while females contains double X-chromosomes. In females, if disorder is on one X-chromosome, other X-chromosome will dominate over other and the disorder is not shown. But in males there is no double X-chromosome to dominate over the affected X-chromosome, disorder is more common in males.