Developmental Biology Flashcards
What is the difference between Fission and Budding?
give example of organisms:
Fission: separation of an organism into 2 new cells; clones (amoebas)
Budding: New organism splits off from existing
(hydra)
What is the difference between Fragmentation and Parthenogenesis?
Fragmentation + Regeneration (sponges):
-single parent breaks off into many parts that develop
Parthenogenesis (honey bees, lizards):
-development of egg w/ out fertilization; resulting adult is haploid
What are Gonads and what is their duty in human reproduction?
gonads are reproductive structures responsible for production of gametes
Male = testes Female= ovaries
What is an ova, ovary, oviduct, and uterus?
Ovary - responsible for the production of Ova (eggs); each female have 2 ovaries
Oviduct- eggs move from ovaries –> uterus via oviduct
Uterus- where embryo development occurs until birth; fertilized ovum implants on the inside wall, ENDOMETRIUM, of uterus
What is the cervix of the uterus?
the opening in the uterus
What do testes consist of and what are those structures responsible for producing?
testes consist of seminiferous tubules that produce sperm and interstitial cells (leydig cells) which are responsible for production of male hormones (testosterone = androgen) and are secreted in the presence of LH
What is the difference between interstitial cells (leydig cells) and sertoli cells?
What sex are these only found?
MALES
Interstitial cells are responsible for production of male hormones (testosterone = androgen) in presence of LH
Sertoli cells surround and nurture sperm in the presence of FSH
What structure are the testes located in and what is that structure’s duty?
scrotum: site of sperm production;
- usually 2 degrees lower than body temp for sperm production
What structure is responsible for the storage of sperm in males?
Epididymis: coiled tube attached to testes
What transfers sperms from one epididymus to urethra in human males?
Vas deferens
What do the seminal vesicles do for you when you ejaculate?
Provides: 3 things:
- mucus (liquid for sperm) to the vas deferens,
- fructose as ATP
- prostaglandins (stimulate uterine contractions that help sperm move into uterus)
“when you bust, sperm squirts out)
What is the prostates duty?
secretes milky alkaline fluid to neutralize acidity of urine, and seminal fluid
What is important about the head of a sperm?
it is called the acrosome (kinda like lysosomes) and contains enzymes to penetrate the female egg
What does SEVEn UP refer to in the male reproductive system?
SEVEn UP
Seminiferous tubules—> Epididymis—> Vas deferens—> Ejaculatory duct—> urethra—> penis
What is Oogenesis vs Spermatogenesis?
Oogenesis: meiotic cell divisions that produce eggs’
oogonia (fetal cells)–mitosis–> primary oocyte–28 days in follicle–> 2ndary oocyte–> ovulation–LH surge–> 2ndary oocyte released from vesicular follicle –fertilization–> ovum,egg (diploid + polar body)
Spermatogenesis: meiotic cell division that produce sperm
Spermatogonia cells—mitosis—> primary spermatocytes—meiosis ll—> 4 spermatids—sertoli cells nourish—-> spermatozoa (sperm)
What are the steps in the menstrual cycle?
Hypothalamus and anterior pituitar initiate: monitor and estrogen and progesterone in blood
Low level—> hypothalamus—> GnRH—> FSH and LH———–> Follicle develops —>FSH stimulate follicle to release lots of estrogen—-> LH surge —> Ovulation (follicle is now corpus luteum -maintained by LH [which along w/ estrogen begins to decrease after ovulation], secretes –> estrogen + progesterone— Development of endometrium–> thickens in prep for implantation of fertilized egg
What happens if there is no implantation occurs during the menstrual cycle?
(negative feedback on AP from increased e+p) terminates production of FSH + LH -due to decreased GnRH from hypothalamus —> *corpus luteum disintegrates ( cause no longer maintained by LH)
What occurs if there is implantation during the menstrual cycle?
embryo (placenta) secretes chorionic gonadotropin
(HCG) —> maintains corpus luteum—> production of e+p remain high —> endometrium stays —> HCG is later replaced by progesterone from placenta
What are the steps of the Ovarian cycle in females?
- Follicular phase: development of egg and secretion of estrogen from follicle
- Ovulation: midcycle release of egg
- Luteal phase: secretion of estrogen and progesterone from the corpus luteum after ovulation
What are the net duties of estrogen and progesterone during the ovarian cycle?
estrogen - thicken endometrium
progesterone - development and maintenance of endometrial wall
What are the steps in the male reproductive cycle?
GnRH–> FSH + LH (also called ICSH, interstitial cell stimulating hormone—> testosterone and androgens from testes).
FSH and testosterone —> influence sertoli cells to promote development of sperms (nourish sperms during development -spermatogenesis).
*Hormone and gamete production are constant unlike females
What are the 4 big stages in growth and development of animals?
- Gametogenesis (sperm/egg formation)
- Embryonic development (fertilization of egg until birth)
- Reproductive maturity (puberty)
- Aging process to death
What is a fetus in embryonic development?
is an embryo that resembles an infant form
What is the duty of both the vitelline layer of sea urchin-echinoderm and the zona pellucida in humans?
prevents fertilization of sperm from other species
What is a very important part of the acrosome reaction?
(sperm release contents of acrosome as it approaches egg; contributes to charge fast block of polyspermy
What is the duty of the blastocyst 5 days after fertilization?
perform zone hatching
zona pellucida degenerates + replaced by underlying layer of tropoblastic cells so it can implant in the uterus
How does fertilization for frogs and amphibians differ from humans?
fertilization doesn’t take place inside a frogs body…
it occurs externally in water
***external fertilization = more eggs and less parental care than internal fertilization due to a less change in fertilization
The vitelline layer forms the fertilization membrane and blocks addition sperm due to the _________ RXN.
Cortical RXN
What is the difference between the Acrosome RXN and the Cortical RXN?
Acrosome rxn: FAST block of polyspermy
Cortical rxn : SLOW block of polyspermy
What is the north pole and south pole of an egg referred to as?
Animal pole = Top of egg
Vegtal pole = Bottom of egg (contains more yolk which is heavier and sinks to the bottom, which then differentiates into extraembryonic membranes that protect + nourish embryo
What occurs during cleavage in embryonic development?
rapid cell divisions w/ out cell growth,
each cell = blastomere (less cytoplasm than original zygote)
What is the difference between indeterminate and determinate cleavages?
Indeterminate cleavage- blastomeres can individually complete normal development even if separated
Determinate cleavage- can NOT develop into complete embryo if separated; each is differentiated into part of the embryo
