Biology Chapter 19: Animal Reproduction and Development

Fission

Asexual reproduction in which the organism divides into two separate organisms

Budding

Asexual reproduction in which there is an outgrowth of a cell or body region resulting in separation and a new organism

Fragmentation

Asexual reproduction in which there is breaking of a body into parts with the regeneration of each part into a new organism

Sexual reproduction

Combination of reproductive cells from two individuals to form a third individual

Hermaphroditism

One individual has both male and female reproductive systems; thus, there is the combination of reproductive cells from one individual to form another individual

Iteroparity

“repeat to beget;” ability to have offspring many times during a lifetime

Semelparity

Death after first reproduction

Diploid

2 sets of chromosomes, 23 paired chromosomes

Haploid

1 set of chromosomes, 23 individual chromosomes

Fertilization

Combination of a sperm and ova; fusion of male and female gametes

External fertilization

Fertilization occurs outside of the male and female bodies

Spawning

Type of external fertilization in which females release eggs and then males release sperm over them; common in aquatic environments

Internal fertilization

Fertilization occurs inside the female

Oviparous

Fertilized eggs are laid outside the female, with nourishment from the egg yolk

Ovoviviparous

Fertilized eggs are retained in the female, with nourishment from the egg yolk

Viviparous

Development occurs inside the mother, and the young receives nourishment from the mother’s blood through the placenta

Anti-mullerian hormone (AMH)

Hormone that prevents the development of female organs

Testosterone

Hormone that promotes the formation of male organs

Wolffian duct (vas deferens)

Male reproductive organ

Mullerian duct (oviduct)

Female reproductive organ

Corpus cavernosum and corpus spongiosum

Male erectile tissue

Urethra

Male plumbing system

Semen

Sperm plus fluid

Seminiferous tubules

Specific site of sperm development

Testes

Organs that produce sperm and hormones

Scrotum

Houses testicles

Epididymis

Location of sperm maturation

Bulbourethral gland

Produces fluid to neutralize acid pH of urethra

Prostate gland

Produces ejaculation force, nutrients, and enzymes

Seminal vesicle

Produces alkaline fluid that improves sperm mobility and neutralizes acidic vaginal pH

Sertoli cells (nurse cells)

Produces the signals for germ cell differentiation and the anti-mullerian hormone

Blood testes barrier

Barrier that separates the sperm from the immune system, as the immune system would label them as foreign

Ovary

Carry and develop ova

Fimbriae

Sweeps ova into fallopian tubes

Fallopian tubes

Transports ova to uterus

Clitoris

Female erectile tissue, sensory nerves

Labium majora

Encloses the vulva

Vulva

Entrance to the reproductive and urinary tracts

Labium minora

Protects vaginal and urethra openings

vestibular glands

Produce lubricant

Vagina

Tube for intercourse, the birth canal, and menstrual flow

Cervix

Connection between the vagina and uterus; lowest part of the uterus

Uterus

Supports developing embryo

Spermatogenesis

The process by which male gametes develop from germ cells in the testes; how sperm is made

Spermatogenium

Precursor cell for spermatocytes; through mitosis, half of these cells replenish stem cells, and the other half differentiate into primary spermatocytes

Primary spermatocyte

Chromosomes duplicate and homologous chromosomes separate to from secondary spermatocytes (meiosis I)

Secondary spermatocytes

Sister chromatids separate to form spermatids (meiosis II)

Spermatids

Cells that develop into sperm

Oogenesis

Development of female sex cells

Oogenium

Precursor cell to oocyte; forms through mitotic division

Primary oocyte

Develops from oogenia; chromosomes duplicate and reside in a primary follicle; occurs before puberty

Secondary oocyte

Sister chromosomes separate to form ootid and a polar body

Ootid

Haploid cell that matures into the ova

Polar body

Small cells that cannot be fertilized. Necessary to reduce genetic material

corpus luteum

Secretes estradiol and progesterone to maintain lining of the uterus during pregnancy

Progesterone

Secreted by ova to attract sperm

Corona radiata

Outside of the ova that sperm bind too

Acrosome

Tip of the sperm

Cortical reaction

Cortical granules fuse with cytoplasmic membrane and release granules, causing glycoproteins to fuse, making a hard shell to prevent any more sperm from penetrating

Ovulation

Unfertilized ovum are released from the ovary to the fallopian tube

Human fertilization

The sperm travels down the fallopian tube to fertilize the ova

Blastula

Hollow ball of cells

Gastrulation

Blastula begins to organize and develop into multiple layers of cells

Protostomes

Blastopore develops into a mouth first

Deuterostomes

Blastopore develops into an anal opening first