The forelimbs of humans, whales, and bats exhibit similarity in basic structure due to common ancestry. This is an example of: MCQ with Answer and Explanation

Explanation:
Viruses are unique entities containing either DNA or RNA, never both simultaneously, enclosed in a protein capsid. They are obligate intracellular parasites, requiring a host cell's machinery to replicate. Despite being biological entities, they can be crystallized like chemicals, as demonstrated by W.M. Stanley with TMV. Thus, statements 2 and 3 are correct.

Explanation:
Ovulation is the rupture of the mature Graafian follicle and release of a secondary oocyte from the ovary, typically around day 14 of a 28-day menstrual cycle, triggered by LH surge. Menstruation is the shedding of uterine lining. Fertilization is fusion of sperm and ovum, implantation is embedding of blastocyst in the endometrium.

Explanation:
The larynx, also called the voice box, contains vocal cords that vibrate as air passes, producing sound. It is located at the top of the trachea. The trachea (windpipe) conducts air; pharynx is the common passage for food and air; bronchi lead to lungs. The larynx is cartilaginous, and in males, the thyroid cartilage forms the Adam's apple.