Biology Questions and Answers

The stillbirth of a second child that is Rh-positive in an Rh-negative woman can occur due to the clumping of fetal blood caused by the production of Rh antibodies in the mother's immune system during a previous pregnancy with an Rh-positive baby. This condition, known as hemolytic disease of the newborn, can be prevented with appropriate medical interventions like Rh immunoglobulin injections.

Xerophytes are plants that have adapted to survive and thrive in arid or dry environments, where water availability is limited. They have evolved various adaptations to cope with the scarcity of water. However, the primary challenge for xerophytes remains the lack of adequate water.

Abiotic factors refer to the non-living components of an ecosystem or habitat that can influence the living organisms within it. Microscope: A microscope is not used to measure abiotic factors. Instead, it is an instrument used to observe and magnify tiny living or non-living things, such as cells, microorganisms, or small structures.

A vestigial structure in humans is the tailbone, also known as the coccyx.
Vestigial structures are anatomical features that have lost their original function over the course of evolution. These structures were once functional and served a purpose in the ancestors of the species but have become reduced or non-functional in the present-day descendants. The tailbone, or coccyx, is a small triangular bone located at the base of the vertebral column in humans. It is a vestige of the tail that was present in the early ancestors of mammals, which had tails for various functions, such as balance, communication, or grasping.

In humans, the sex of a child is determined by the combination of sex chromosomes received from the parents. The mother contributes an X chromosome, and the father contributes either an X chromosome (resulting in a female child) or a Y chromosome (resulting in a male child).

Since the father can contribute either an X or a Y chromosome, there are two possible outcomes for the sex of the child: male (XY) or female (XX). The chance of having a male child (XY) is equal to the chance of having a female child (XX).
Therefore, the probability of having a male child is 1 out of 2, which is represented as ½.