animal cell

What is sexual reproduction?

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

What is asexual reproduction?

Creation of offspring without fusion of egg and sperm; one parent clones offspring.

What are four types of asexual reproduction?

Fission, budding, fragmentation with regeneration, parthenogenesis.

What is parthenogenesis?

Development of a new individual from an unfertilized egg.

Why is sexual reproduction considered a 'twofold cost'?

Sexual females have half as many daughters as asexual females.

What are the advantages of sexual reproduction?

Genetic variation, adaptation rate increase, elimination of harmful genes.

What is ovulation?

Release of mature eggs at the midpoint of a female cycle.

What is hermaphroditism?

Condition where an individual has both male and female reproductive systems.

What is internal fertilization?

Fertilization that occurs within the female reproductive tract.

What is external fertilization?

Fertilization where eggs are shed and fertilized outside the body.

How do species with internal fertilization protect embryos?

Through structures like amniote eggs and by retaining embryos in the female.

What are gonads?

Sex organs that produce gametes.

What are the female gonads?

Ovaries.

What are follicles?

Egg chambers containing an oocyte and support cells.

What is the corpus luteum?

Hormone-secreting tissue formed after ovulation from the follicle.

What is the function of the oviduct?

Carries the egg from the ovary to the uterus.

What is the endometrium?

Lining of the uterus rich in blood vessels.

What is the role of the vagina?

Receives sperm during copulation and serves as the birth canal.

What are mammary glands?

Glands that secrete milk, important for mammalian reproduction.

What are the male gonads?

Testes.

Where are sperm formed?

In the seminiferous tubules of the testes.

What do Leydig cells produce?

Testosterone and other androgens.

What is the function of the epididymis?

Stores and matures sperm.

What are the components of semen?

Sperm plus secretions from seminal vesicles, prostate gland, and bulbourethral glands.

What is spermatogenesis?

Production of mature sperm from precursor cells.

What is oogenesis?

Development of mature egg cells (oocytes).

How does oogenesis differ from spermatogenesis?

One egg forms per meiosis cycle in oogenesis; four sperm form in spermatogenesis.

What hormone initiates reproductive hormone release?

Gonadotropin-releasing hormone (GnRH).

What do FSH and LH do?

FSH stimulates Sertoli cells; LH stimulates Leydig cells.

What hormone provides negative feedback on FSH?

Inhibin.

What hormone regulates GnRH, FSH, and LH?

Testosterone.

What defines the ovarian cycle?

Changes in the ovaries including follicular phase, ovulation, and luteal phase.

What defines the uterine cycle?

Changes in the uterus including menstruation, proliferation, and secretion phases.

What causes menstruation?

Shedding of the endometrium when no embryo implants.

What is menopause?

Cessation of ovulation and menstruation after ~500 cycles.

How do estrous and menstrual cycles differ?

Menstrual: endometrium shed, no restricted sexual receptivity; Estrous: endometrium reabsorbed, sexual receptivity during 'heat'.

Where does fertilization occur?

In the oviduct.

What is cleavage?

Rapid mitosis without growth, producing blastomeres.

What is a blastocyst?

Ball of cells with a cavity that implants in the endometrium.

What hormone prevents menstruation during pregnancy?

Human chorionic gonadotropin (hCG).

What is organogenesis?

Development of body organs from three germ layers.

What triggers labor?

Estradiol, oxytocin, and prostaglandins working in a positive feedback loop.

What are the three stages of labor?

Dilation of cervix, delivery of infant, delivery of placenta.

What is lactation?

Production of milk by mammary glands.

What are some contraception methods?

Abstinence, condoms, pills, IUDs, surgical sterilization.

What are examples of assisted reproductive technologies?

In vitro fertilization (IVF), intracytoplasmic sperm injection (ICSI).

What are the three germ layers?

Ectoderm (outer), mesoderm (middle), endoderm (inner).