Reproduction and Development in the Animal Kingdom

These flashcards cover key terms and concepts related to reproduction and development in animals, including definitions of reproductive processes, structures, and cycles.

Asexual Reproduction

The creation of offspring without the fusion of male and female gametes.

Sexual Reproduction

The creation of offspring by the fusion of a male gamete (sperm) and female gamete (egg) to form a zygote.

Budding

A form of asexual reproduction where new individuals arise from outgrowths of existing ones.

Fission

The separation of a parent organism into two individuals of approximately equal size.

Fragmentation

The breaking of the body into pieces, some of which develop into adults.

Regeneration

The regrowth of lost body parts that accompanies fragmentation.

Parthenogenesis

The development of a new individual from an unfertilized egg.

Gonads

Specialized organs in animals that produce gametes; testes in males and ovaries in females.

Copulation

The sexual union that facilitates the reception of sperm.

Hermaphroditism

A reproductive strategy where individuals have both male and female reproductive systems.

External Fertilization

A process where eggs shed by the female are fertilized by sperm in the external environment.

Internal Fertilization

A process where sperm are deposited in or near the female reproductive tract and fertilization occurs within the tract.

Sertoli Cells

Cells in the seminiferous tubules that nourish developing sperm.

Leydig Cells

Cells located between seminiferous tubules that secrete testosterone and other androgens.

Menstruation

The process where the uterine lining is sloughed off if an oocyte is not fertilized.

Gametogenesis

The production of gametes, including both spermatogenesis in males and oogenesis in females.

Estrous Cycle

A reproductive cycle in most mammals where the endometrium is reabsorbed if there is no pregnancy.

Zygote

The fertilized egg that is the product of the combination of sperm and egg.

Cortical Reaction

The process that prevents polyspermy as a sperm enters the egg.

Gestation

The condition of carrying an embryo or fetus in the uterus.

In Vitro Fertilization (IVF)

A reproductive technology that mixes oocytes with sperm in culture dishes to create embryos.