vocab

asexual reproduction - a type of reproduction that involves only 1 parent

  • occurs in different ways, such as fission, budding, fragmentation

  • offspring are clones of parents & are genetically identical to each other

  • offspring are also produced in short amount of time - time isn’t spent finding a mate

    • is an advantage

  • disadvantage - low genetic diversity (cuz the same alleles are passed on to each generation)

    • means low adaptability, which can be dangerous when environment changes

sexual reproduction - type of reproduction that involves 2 parents

  • gametes are produced through meiosis & fuse to form zygote

  • offspring are similar but aren’t genetically identical to parents & siblings

  • requires more time & energy - disadvantage

  • but does result in new genetic variation = advantage

menstrual cycle - is comprised of the ovarian cycle & uterine cycle

ovarian cycle - the cyclic changes seen in the ovaries

  • can be divided into 3 parts:

    • follicular phase

    • ovulation

    • luteal phase

uterine cycle - changes that happen in uterus

  • can be divided into 3 parts

    • menstruation

    • proliferative phase

    • secretory phase

follicles - small sac-like structures that’re filled with fluid

  • located in ovaries

  • each follicle contains one immature egg

oestradiol - a steroid hormone that regulates the menstrual cycle

ovulation - the release of a mature egg from the ovaries

  • is caused by the increase of LH during the ovulation phase

corpus luteum - a temporary organ formed in each menstrual cycle from the ruptured follicle

  • secretes oestradiol & progesterone

  • when it disintegrates it forms the white corpus albicans

endometrial - the inner lining of the uterus that’s shed during menstruation

negative feedback (at least in the case of the ovarian & uterine cycle) - occurs when an increase in one hormone, inhibits secretion of other hormone

positive feedback (at least in the case of the ovarian & uterine cycle) - occurs when increase of one hormone causes increases in levels of other hormones

acrosome - a organelle at end of sperm that contains digestive enzymes that aid with fertilization

capacitation - biochemical & physiological changes that the sperm undergoes in order to fertilize egg

egg activation - a series of steps that occur once the plasma membranes of oocyte & sperm fuse

  • involves rise of calcium in oocyte

  • stimulates meiosis II in nucleus

  • cortical reaction occurs

cortical reaction - cortical granules fuse the oocyte cell membrane, releasing their contents

gametogenesis - formation of haploid gametes

  • in males - referred to as spermatogenesis

  • in females - referred to as oogenesis

spermatogenesis - process of formation of male gametes or sperm

  • occurs with onset of puberty

oogenesis - process of formation of female gametes or mature ovum

  • begins during foetal development

spermatogonia - diploid cells that hv 44 autosomes & 2 sex chromosomes

  • initiate spermatogenesis by dividing mitotically

acrosome reaction - the acrosome releases hydrolytic enzymes, which digest the zona pellucida & aid with fertilization

polyspermy - fusion of more than one sperm with one egg

  • results in a non-viable zygote

cortical reaction - a mechanism designed to prevent polyspermy

  • the cortical granules fuse with plasma membrane & release their contents into space between zona pellucida & plasma membrane through exocytosis

cleavage - a series of rapid cell divisions undergone by the zygote

morula - solid ball of cells formed from mitotic divisions by zygote

  • zona pellucida still surrounds the morula

  • i think this is also when the embryo is at the 16-cell stage

outer trophoblast - cells that will form the placenta

inner cell mass - the cells within the embryo that will become the embryo

blastocoel - a fluid-filled cavity that develops inside the early form of an embryo

blastocyst - a hollow ball of 32 cells

umbilical cord - a rope-like structure attaching the foetus to the placenta

  • allows nutrients and oxygen to transfer from mother to foetus

placenta - organ that develops during pregnancy

  • allows oxygen, nutrients & waste products to be exchanged between mother & foetus’s blood supplies

  • composed of both maternal & embryonic tissue

  • maternal portion of placenta is the uterine endometrium

  • foetus portion of placenta is chorionic villi

  • also secretes progesterone & oestradiol to maintain the pregnancy