Tamil Nadu Board Class 12 Zoology — Flashcards for Quick Revision

A: Reproduction is a biological process by which organisms produce their young ones. It is fundamental because: (1) It ensures the continuation of species across generations, (2) It introduces genetic va

A: Asexual Reproduction: Reproduction by a single parent without gamete formation. Offspring are genetically identical to the parent (uniparental inheritance). No genetic variation occurs. Examples: Amoe

A: Binary fission is the division of a parent organism into two identical daughter individuals. The nucleus divides first (mitotically or amitotically), followed by cytoplasm division (cytokinesis). The

A: The four main functions are: (1) Production of gametes (sperms and ova), (2) Transport and sustenance of gametes, (3) Nurturing of the developing offspring, and (4) Production of reproductive hormones

A: The scrotum is a pouch of skin hanging outside the abdominal cavity that contains and protects the testes. Its primary function is thermoregulation—it maintains a temperature 2-3°C lower than normal b

A: Sertoli cells (nurse cells) are located in the seminiferous tubule epithelium and provide nourishment to developing sperms until maturation. They also secrete inhibin for feedback control of sperm pro

A: Reproductive health refers to a state of complete physical, mental, and social well-being in all matters related to reproduction. It is important because: (1) Healthy people with healthy reproductive

A: Amniocentesis is a prenatal diagnostic technique that involves taking a small sample of amniotic fluid surrounding the fetus to detect chromosomal abnormalities. It is statutorily banned in India beca

A: Sex ratio is the number of females per 1,000 males in a population. In India, the child sex ratio has declined from 927 to 919 females per 1,000 males over decades. Female foeticide is the intentional