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58 Cards in this Set
- Front
- Back
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In what kind of environments does asexual reproduction usually take place? |
Stable environments, such as marine ecosystems, that do not require shuffling of genes that occurs with sexual reproduction |
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What is a type of asexual reproduction that involves the regeneration of pieces/segments of the animals and occurs in sea stars? |
Fragmentation |
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What is a type of asexual reproduction that involves the emergence of a tumor in which mitosis occurs and it breaks off, becoming an individual? |
Budding |
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What does sexual reproduction, on a basic level, entail? |
Fertilization: The fusion of gametes (sperm and egg) to make a zygote. |
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Where and how are gametes produced? |
In gonads, by meiosis |
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What is the name given to the process of the formation of sperm in the seminiferous tubules of the testis? |
Spermatogenesis |
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How many sets of chromosomes (or ploidies) does a germinal cell in a seminiferous tubule have? |
Two, it is diploid. |
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What daughter cells does a germinal cell produce when divided by mitosis? |
One is a stem cell and one a primary spermatocyte (diploid) |
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Where is the stem cell? Where is the primary spermatocyte? |
Remains at the periphery; closer in towards lumen |
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What do the primary spermatocytes undergo and what do they become? |
Meiosis 1; Two secondary spermatocytes (haploid, one set of chromosomes each) |
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What do the secondary spermatocytes undergo and what do they become? |
Meiosis 2; 4 haploid Spermatids |
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What do the spermatids undergo and what do they undergo? |
Maturation; 4 spermatozoa or sperm cells (haploid) |
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What does a matured sperm cell have that a spermatid doesn't? |
Flagellum/tail, Mitochondria/midpiece, and acrosome/head |
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What is the acrosome of sperm cells made of? |
It is a bag/organelle that carries hydrolytic enzymes derived from lysosomes. |
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Where in the seminiferous tubule is the sperm cell? |
It is pushed from periphery by the production of cells toward the lumen (inner cavity of tubule) |
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Once it gets pushed into the lumen of the tubule, where does the sperm cell go? |
It gets pushed by smooth muscle contractions of the tubule to the epididymis, where it is stored until ejaculation. |
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During ejaculation, where do the sperm cells go from the epididymis? |
Parystaltic smooth muscle contractions push the sperm out of the epididymis into the vas deferens |
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Where do the sperm cells go after exiting the vas deferens? |
They go into the ejaculatory duct. |
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Where does the ejaculatory duct lead to? |
The urethra, then the penis. |
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How many vas deferens are there in a male reproductive system? |
Two, one for each testicle. |
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Where is the seminal vesicle and what does it do? |
It is behind the bladder and it secretes amino acids and fructose to the sperm cells for energy to swim when it enters the vagina. |
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Where is the prostate gland and what does it do? |
It is under the bladder and it adds secretions into the sperm to balance the low pH of the acidic vagina opening. |
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Where is the bulbourethral gland and what does it do? |
It is behind the urethra and under the prostate gland, it adds secretions to the urethra before ejaculation to neutralize the acidic urine in the pathway and lubricate the tip of the penis. |
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How does an erection take place? |
When aroused, the veins become blocked, preventing uptake of blood. This increases blood pressure in the erectile tissue of the penis, causing an erection. |
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How many sperm cells does a male reproductive system produce a day? |
3 million. |
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What are the bulbourethral, prostate, and seminal vesicles also called? |
Accessory glands. |
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In females, what do the diploid germinal cells produce in ovary with mitosis? |
Diploid primary oocytes. |
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What does the primary oocyte combine with to become a follicle? |
A follicular/nurse cell |
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What does the follicle undergo and when? |
It undergoes meiosis 1, just performs prophase 1 and stops. This is while the female is a fetus. |
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When does a female produce its follicles? |
While it's a fetus. It produces follicles that undergo prophase 1 of meiosis 1 and stop. |
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When does a female begin developing its follicles past prophase 1 of meiosis 1 and at what rate? |
During puberty, one or two a month. |
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What does a follicle undergo in its development during puberty? |
It continues meiosis 1 from where it left off at prophase 1. |
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What does a follicle produce after completion of meiosis 1 during puberty? |
A secondary oocyte (haploid) with most of the cytoplasm, and a 1st polar body (haploid) with almost no cytoplasm, basically a dud. |
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What happens to the secondary oocyte follicle during meiosis 2? |
It begins developing further by becoming larger inside the ovary, then stops developing at metaphase 2 of meiosis 2. |
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What happens to the secondary oocyte follicle after it stops developing inside the ovary up to metaphase 2 of meiosis 2? |
Ovulation: It is released by the ovary into the body cavity, the secondary oocyte breaks open from its cover of follicle cells which scatter away, and usually the secondary oocyte is swept up by the fallopian tube/oviduct. |
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What happens to the secondary oocyte inside the oviduct? |
It comes into contact with a sperm cell and engages in fertilization, during which it finishes metaphase II and fully develops into an ovum/egg (gamete). |
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What happens to the sperm cell (haploid) and ovum (haploid) as they fertilize? |
They fuse into a zygote (diploid) that will eventually enter the uterus to become an embryo. |
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How many gametes are produced by a female germinal cell versus a male germinal cell? |
One, four. |
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What is the pathway of the male reproductive system? |
Seminiferous tubules->epididymus->vas deferenses->ejaculatory duct->urethra->penis. |
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What is the pathway of the female reproductive system? |
Vagina->cervix->uterus->fallopian tubes/oviducts->ovaries. |
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What happens to the 1st polar body as the oocyte develops into a ovum? |
It either dies out or becomes a 2nd polar body. Either way, useless. |
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What is the hypothalamus and what does it do? |
A part of the brain that controls the pituitary gland |
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For reproduction, what does the hypothalamus do? |
It secretes gonadotropin-releasing hormones to stimulate the pituitary. |
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When it is stimulates by the hypothalamus for reproduction, what does the pituitary gland do? |
It secretes FSH and LH |
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What is the target for LH and FSH in males? |
LH target is hormone secreting cells that produce testosterone. FSH target is seminiferous tubules to stimulate spermatogenesis. |
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What is the target for testosterone? |
Seminiferous tubules in the testes, as well as the hypothalamus to relay feedback to keep testosterone levels stable (inhibitory). |
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In females, what is the target for FSH? |
Follicles and corpus luteum, which are stimulated to secrete estrogen and progesterone |
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What is the target for estrogen and progesterone? |
The endometrium (wall of uterus), which it stimulates to build blood vessels in preparation for embryo. |
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In females, what happens when estrogen levels reach a peak? |
The LH targets follicles, which are stimulates to ovulate within 24 hours. |
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What happens to ovulated follicles? |
They either are sucked in by the fallopian tube/oviduct or are left behind and become corpus luteum. |
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What happens if a pregnancy doesn't occur? |
The progesterone and estrogen levels become high together, triggering inhibition in the hypothalamus that causes them to come down. The corpus luteum and blood vessels deteriorate. |
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How does a pregnancy occur? |
The zygote turns into a multicellular blastocyst, and enters the uterus, where it attaches to the outer skin of the uterus as a blastula and develops into an embryo. |
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What happens to the endometrium and corpus luteum if a pregnancy does occur? |
The embryo releases HCG which acts like LH to stimulate corpus luteum, keeping endometrium working. |
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What happens to the embryo after 45 days? |
It becomes a placenta inside of a sac of amniotic fluid. |
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How does a mother give nutrients to a placenta? |
Through capillaries inside the umbilical cord. The nutrients flow through the capillaries and enter the baby's blood. |
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How does a placenta get rid of its waste? |
The waste flows into capillaries and enters mother's blood. |
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Do cells ever mix between mother and placenta? |
Sometimes they do get exchanged between baby and mother, but generally are kept apart by sac. |
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What happens to the corpus luteum when the placenta is formed? |
The placenta is able to produce its own progesterone to maintain the endometrium, so there is no more HCG or LH and the corpus luteum deteriorates. |
