Question

1. Which of the following is an example of a vestigial trait?

   		Bat wing bones are similar in structure to seal flipper bones
   		Goosebumps on humans have no functional purpose.
   		The beaks of Galapagos Finches are variable due to their evolution from a common ancestor
   		Feathers on birds are an adaptation that was originally meant for body temperature regulation

Women with baldness (a sex-linked trait) must have received their alleles from

		Their father
		At least one maternal and one paternal grandparent
		Their mother
		Their mother and father
		2 of the answers are correct

Answer 1

1.

Vestigial traits are retension of some characters which have no present day function or relevance. they can be considered as evidence of evolution. Human appendix, wing of flightless birds, coccyx are some examples.

Here 4 statements are given and the question is to find an example of vestigial organ

- bat wing bones are similar in structure to seal flipper bones. This is an example for homologous stuctures, structures present in different animals having same anatomy. These are not vestigial.

- The beaks of Galapagos Finches are variable due to their evolution from a common ancestor. This is an example of Adaptive Radiation.Here changes in beak size help them to survive. Not vestigial structures.

- Feathers on birds are an adaptation that was originaly meant for body temperature regulation. These are not vestigial. The structures are for thermoregulation.

- Goosebumps on humans have no functional purpose. It is an example for vestigial trait. the piloerection or goosebump has lost its original function in humans which was to creare insulation .

it is the answer.

Goosebumps on humans have no fuctional purpose- Vestigial trait

2.

Baldness is a sex linked recessive trait. It is carried by the X chromosome . Females can get sex linked recessive disease when abnormal gene on the X chromosome from each parent would be required.

Here in the question a women is with baldness. If she received alleles from her father only, she will be a carrier only.If she received alleles from mother only, she will be a carrier only. Here in both cases since the female have 2 x chromosomes the dominant x will compensate the defect on the recessive x.

The women will get the disease only if she receive alleles from both parents

- At least one maternal and one paternal

- their mother and father

2 of the answers are correct