Term | Definition |
reproduction | to make a copy of something |
why is reproduction needed for the survival of a species, not an individual? | reproduction allows for a species to survive. species that have favorable adaptations will survive and reproduce, allowing for the species to survive. |
testes | produce and store sperm cells |
epididymis | storage area on top of the tests (place where sperm matures) |
sperm | head=nucleus
mid piece=mitochondria
tail/flagellum=used to propel sperm forward
seme is released during ejaculation |
sperm duct/vas deferens | carries sperm out of the tests after being stored in the epididymis towards urethra |
seminal vesicles | provide nutrients for the sperm |
urethra | tube that carries semen through the penis to the outside of the body |
penis | intro of sperm cells into the vagina of female reproductive track |
functions of the male repro system | produce sperm, deposit sperm in females, produce hormones |
functions of the female repro system | production of egg cells (1n gametes), care for fertilized egg (prep body to nourish a developing embryo), produce hormones |
ovaries (female gonads) | produce egg cells (ova) in tiny cavities called follicles |
ovulation | one a month, a follicle will rupture and release one egg |
oviduct (fallopian tubes) | carries egg to uterus, fertilization occurs here |
uterus (womb) | thick muscular walled organ with rich blood supply, site of embryo growth |
vagina | receives sperm cells from male, birth passage for baby |
menstrual cycle | preparation of uterus for a fertilized egg |
follicle stage (10 days) | starts when estrogen levels are low, causes the pituitary gland to release FSH & LH, a follicle is formed, egg matures here, estrogen levels increase, increased estrogen levels cause uterus lining to thicken |
ovulation (3-4 days) | a large rush of FSH and LH is released causing the follicle to rupture. egg goes to fallopian tubes |
corpus lutetium (10-14 days) | ruptured follicle forms a yellowish structure called the corpus luteum, corpus luteum secretes progesterone, which further enhances the vascularization or the thickening of the uterine lining |
menstruation (3-7 days) | breakdown of uterine lining in the absence of a fertilized egg, occurs when fertilization doesn't take place |
purpose of meiosis | to create sex cells (gametes) |
gametes | sex cells |
meiosis | sex cells, 2 divisions, 46 chromosomes, 23 chromosomes at end, dna is varied, sexual reproduction, 4 cells produced, haploid |
mitosis | body cells, 1 division, 46 chromosomes, 46 chromosomes, identical dna, asexual reproduction, 2 cells produced, diploid |
spermatogenesis | formation of sperm in the testes |
oogenesis | formation of eggs in the ovaries |
random fertilization | distribution of homologous chromosomes between resulting nuclei is random, which results in variation |
synapsis | pairing of homologous chromosomes |
tetrad | a 4 pair structure that forms during meiosis prophase |
crossing over | exchange of genetic material during synapsid |
homologous chromosomes | corresponding chromosomes from the opposite sex parent |
disjunction | breaking of a tetrad in anaphase 1 |
diploid | 2 sets of chromosomes |
haploid | 1 set of chromosomes |
uterus changes | uterine wall expands, forming placenta. umbilical chord connects the mother to child through the placenta. amniotic sac and fluid cushions and protects the baby from poor stimuli. |
placenta | a temporary organ through which the fetus receives for and oxygen from the mothers body and removes wastes |
umbilical chord | the structure that connects the fetus and placenta |
identical twins | one egg is fertilized by one sperm |
fraternal twins | two eggs and two sperm injected into the uterus |
zygote | fertilized egg |
zygote formation | fusion of male and female gamete |
embryo formation | cleavage, blastula, gastrula, growth |
embryo | early stage of development |
differentiation | cells become different from one another |