Reproduction

What is Asexual Reproduction?

A process involving one parent organism that reproduces without specialized reproductive organs, resulting in genetically identical offspring.

List some forms of asexual reproduction.

Binary Fission, Budding, Spores, Regeneration, Vegetative Propagation.

What is the primary method of cell division in asexual reproduction?

Mitosis and Cytokinesis.

What is Sexual Reproduction?

A process involving two parents contributing genetic material, leading to genetic variation among offspring.

What type of cells are produced during Sexual Reproduction?

Gametes (sex cells) produced through Meiosis.

How does Sexual Reproduction contribute to the survival of species?

It enhances genetic variation, increasing adaptability to environmental changes.

What is Conjugation in lower organisms?

A form of sexual reproduction where genetic material is exchanged via a conjugation bridge.

What roles do Ovaries and Testes play in sexual reproduction?

Ovaries produce ova (eggs) and Testes produce sperm, both are haploid reproductive cells.

What are Hermaphrodites?

Organisms that possess both male and female reproductive organs.

What is Gametogenesis?

The process of producing gametes, including Oogenesis (for eggs) and Spermatogenesis (for sperm).

What occurs during Oogenesis?

From one primary oocyte, one ovum and three polar bodies develop.

What happens in Spermatogenesis?

From one primary spermatocyte, four spermatozoa are formed.

Describe Sperm Characteristics.

Sperm are small, numerous, mobile, and have enzymes to penetrate the egg's outer layers.

Describe Egg Characteristics.

Eggs are larger, fewer in number, non-mobile, and typically contain yolk as nourishment.

What is Fertilization?

The process where sperm penetrates the egg, forming a diploid zygote.

What are the two types of fertilization?

External fertilization in water and internal fertilization within the female's reproductive system.

What occurs during Cleavage in embryonic development?

The zygote undergoes mitotic divisions to form a morula.

What is Gastrulation?

The process of forming three primary germ layers in the embryo.

What are the three primary germ layers?

Ectoderm, Endoderm, and Mesoderm.

What is Differentiation in embryonic development?

The process where embryonic cells become specialized for different functions.

What is External Development?

Development that takes place outside the parent's body, common in aquatic species.

What is Internal Development?

Development that occurs within the female reproductive system, offering protection to embryos.

What are Extraembryonic membranes in bird eggs?

Yolk sac (nutrients), Amnion (shock absorption), Allantois (metabolic waste and gas exchange), Chorion (gas exchange under the shell).

What is the role of the placenta in mammals?

It is the site of nutrient and waste exchange between the mother and embryo.

What happens during Labor in childbirth?

Uterine contractions, cervix enlargement, and the amnion breaking.

What is a zygote?

The fertilized egg resulting from the union of sperm and egg.

What is the Menstrual Cycle?

The monthly cycle of hormonal changes and preparation for potential pregnancy.

What is Ovulation?

The release of an egg from a mature follicle, typically occurring around day 14 of the menstrual cycle.

What does the Corpus Luteum do?

It releases progesterone to maintain the uterine lining after ovulation.

What happens if fertilization does not occur?

LH levels drop, causing menstruation, and leading to the shedding of the uterine lining.

What is the Estrous Cycle?

Periodic changes in female sex organs and mating desire, seen in many mammals other than humans.

What do hermaphrodites do to reproduce?

They often reproduce with other hermaphrodites rather than self-fertilizing.

What is the purpose of the amnion during fetal development?

It surrounds the fetus and contains amniotic fluid for shock absorption.

What distinguishes fraternal twins from identical twins?

Fraternal twins result from two separate eggs and sperm; identical twins result from one egg and sperm splitting.

What risks are associated with external fertilization?

High predation rates and loss of gametes due to environmental factors.

What is Menstruation?

The shedding of the uterine lining when fertilization does not occur.

What are the functions of the ovary in the female reproductive system?

They mature eggs and produce hormones like estrogen.

What happens to the zygote after fertilization?

It undergoes cleavage, blastulation, and gastrulation before developing further.

What is the significance of genetic variation in sexual reproduction?

It allows for evolutionary adaptability and resilience in populations.

What leads to the formation of the placenta during pregnancy?

The chorionic villi from the chorion interdigitate with the uterine wall for nutrient exchange.

What is meant by ‘spawn’ in external fertilization?

The simultaneous release of eggs and sperm into the water by fish.

What is parthenogenesis?

A form of reproduction where an egg develops without fertilization by sperm.