bio ch 37

What does sexual reproduction produce?

haploid gametes from meiosis

nonmotile cells

eggs/ova

male gametes

sperm

diploid zygote

the product from the union of two haploid gametes during fertilization (meiosis)

asexual reproduction

Process by which a single parent reproduces by itself

budding

new individuals form as outgrowths, or buds, from the bodies of other individuals; reef corals produce large colonies by budding

fission

an individual splits into two or more pieces that grow into new individuals

advantage of asexual reproduction

favorable combinations of genes are maintained.

disadvantages of sexual reproduction

� Potential mates have to find each other and succeed in mating, despite the presence of competitors and predators � Breaks up favorable combinations of genes

primary reproductive organs

gonads

accessory reproductive organs

ducts, glands, and external genitalia

secondary sexual characteristics

properties of nonreproductive tissues and organs that are distinctive in each sex; for example, facial hair and deep voice of human males

gametogenesis

process by which gametes are produced (spermatogenesis in males and oogenesis in females)

sertoli cells

assist sperm production

interstitial cells

produce testosterone

germ cells in testes

produce sperm

seminiferous tubules

Narrow, coiled tubules that produce sperm in the testes.

vas deferens

tube that carries sperm from the epididymis to the urethra

ovarian follicles

Areas within the ovary in which individual eggs develop

ovulation

the ovum is released by rupture of the mature follicle

fertilization

Fusion of an egg and sperm cell

external fertilization

most aquatic animals release gametes into the water (spawning)

internal fertilization

male inserts sperm inside the reproductive tract of a female

advantages of internal fertilization

In terrestrial animals, it keeps gametes and zygote moist. � Some females can store sperm for future use. � In mammals, the zygote develops for an extended time inside the female.

behavior

males and females associate in species-specific ways and employ behaviors to signal reproductive readiness, such as estrus or "heat.

sex determination

males are XY, females are XX

environmental sex determination

the environment determines sex of offspring

sequential hermaphrodites

individuals that possess male or female reproductive function and then switch to the other

Follicle-stimulating hormone (FSH)

secreted by the pituitary gland to stimulate maturation of the egg cell (ovum)

luteinizing hormone (LH)

secreted by the pituitary gland to promote ovulation

somatic cells

produce testosterone, estrogen, and progesterone in the gonads

oviducts

fallopian tubes

endometrium

inner lining of the uterus

implantation

The process by which the zygote attaches to the uterine wall

induced ovulation

- triggered by copulation
� Sensory neurons in the cervix send action potentials to the brain, where the hypothalamus is stimulated to release GnRH, resulting in a surge in LH secretion from the anterior pituitary

spontaneous ovulation

timing of the LH surge is under hormonal control

menstruate

periods in primates

estrous cycle

the female reproductive cycle of mammals other than primates

corpus luteum

Endocrine tissue which produces hormones, estrogen, and progesterone which prepares the uterine lining for receiving an embryo

placenta

A structure that allows an embryo to be nourished with the mother's blood supply

semen

A thick fluid containing sperm and other secretions from the male reproductive system
- produced from seminal vesicles and prostate gland

how many tissues are there in the penis

3 that can be expanded by blood

embryonic diapause

embryo starts to develop, but then development stops for awhile

delayed implantation

a delay in implantation of an embryo into the uterus, allowing for the proper timing of birth

semelparous

single reproductive episode before death

iteroparous

individuals can reproduce two or more times during their lives

What differences and similarities exist between mammals that exhibit induced ovulation and those that ovulate independently of mating?

An LH surge triggers ovulation in mammals with both induced and spontaneous ovulation. In induced ovulation, the LH surge results from nerve signals during copulation that stimulate the hypothalamus. � When sperm are provided by copulation, ova are provid