11.4 Reproduction HL
Terms in this set (14)
11.4.1 Annotate a light micrograph of testis tissue to show the location and function of interstitial cells (leydig cells), germinal epithelium cells, developing spermatozoa and Sertoli cells.
11.4.2 Outline the processes involved in spermatogenesis within the testis, including mitosis, cell growth, the two divisions of meiosis and cell differentiation.
cell division by mitosis to form more cells = spermatogonia;
spermatogonia to form larger cells = primary spermatocytes;
primary spermatocytes divide by meiosis;
two divisions of meiosis;
haploid cells = spermatids formed;
differentiation of spermatids into sperm;
growth of tail;
FSH, testosterone and LH all needed for spermatogenesis;
sperm stored = maturation in epididymis to gain motility;
fluid added to sperm by seminal vesicle;
fluid from seminal vesicle contains nutrients and mucus;
fluid added to sperm by prostate gland contains alkali minerals;
11.4.3 State the role of LH, testosterone and FSH in spermatogenesis.
11.4.4 Annotate a diagram of the ovary to show the location and function of germinal epithelium, primary follicles, mature follicle and secondary oocyte.
11.4.5 Outline the processes involved in oogenesis within the ovary, including mitosis, cell growth, the two divisions of meiosis, the unequal division of cytoplasm and the degeneration of polar body.
11.4.6 Draw and label a diagram of a mature sperm and egg.
head with nucleus;
middle piece with mitochondria;
cytoplasm (must show large volume relative to nucleus - suggest four to
one ratio of diameter at a minimum);
(first) polar cell / polar body (needs to be drawn on the outside of the cell);
follicle cells / corona radiata;
cortical granules (need to be drawn in vicinity of plasma membrane);
11.4.7 Outline the role of the epididymis, seminal vesicle and prostate gland in the production of semen.
11.4.8 Compare the processes of spermatogenesis and oogenesis, including the number of gametes and the timing of the formation and release of gametes.
mitosis before meiosis;
cell growth before meiosis;
LH / FSH;
testes versus ovaries:
spermatogenesis starts at puberty versus oogenesis starts in the fetus;
spermatogenesis until death versus oogenesis until menopause;
spermatogenesis continuously versus oogenesis in a cycle;
millions of sperm daily versus one egg per month;
ejaculation of sperm any time versus ovulation in middle of menstrual cycle;
four sperm per meiosis / spermatogonium versus one
egg per meiosis / oogonium;
spermatogenesis involves equal divisions versus oogenesis
involves unequal cell / cytoplasm divisions;
no polar bodies in spermatogenesis versus 2 or 3 polar
bodies in oogenesis;
spermatogenesis involves Sertoli /
nurse cells versus oogenesis does not;
meiosis II completed before fertilization in spermatogenesis
versus after in oogenesis;
testosterone needed for spermatogenesis versus
not needed for oogenesis;
11.4.9 Describe the process of fertilization, including the acrosome reaction, penetration of the egg membrane by a sperm and the cortical reaction.
sperm enters oviduct (fallopian tube) / sperm swims towards egg /
(secondary) oocyte / ovum;
sperm attracted to egg / sperm attach to receptors in zona pellucida / chemotaxis;
acrosome reaction / release of (hydrolytic) enzymes from acrosome;
penetration of zona pellucida / jelly coat;
membranes of egg and sperm fuse / sperm (head) penetrates egg membrane;
cortical reaction / granules released to the outside of egg;
zona pellucida hardens / fertilization membrane forms to prevent polyspermy;
nucleus of secondary oocyte completes meiosis II;
fusion of nuclei / (diploid) zygote forms;
11.4.10 Outline the role of HCG in early pregnancy.
11.4.11 Outline early embryo development up to the implantation of the blastocyst.
fertilized egg called a zygote;
cell divides by mitosis;
early divisions of zygote result in reduction in quantity of
cytoplasm per cell / no increase in overall size;
first divisions occur while zygote in fallopian tube / oviduct;
several divisions result in the formation of a bundle of cells called a morula;
further divisions result in a hollow ball of cells /
fluid filled ball of cells / blastocyst;
implantation occurs up to seven days after fertilization;
11.4.12 Explain how the structure and functions of the placenta, including its hormonal role in secretion of estrogen and progesterone, maintain pregnancy.
structure: [3 max]
placenta is composed of fetal and maternal tissues;
villi increase surface area;
vascularization / capillaries within placental villi;
intervillous spaces through which maternal blood flows;
function: [4 max]
secretes estrogen to maintain uterine lining;
secretes progesterone to maintain uterine lining;
gas / nutrient exchange for fetus;
removes waste products;
acquiring passive immunity / antibodies cross placenta;
11.4.13 State that the fetus is supported and protected by the amniotic sac and amniotic fluid.
11.4.14 State that materials are exchanged between the maternal and fetal blood in the placenta.