Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

mcdb1b > reproduction > Flashcards

reproduction Flashcards

1
Q

Reproductive strategies

A

Sexual reproduction

Asexual reproduction

Mixed

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

sexual reproduction

A

Fusion of a sperm and an egg(haploids) forms a zygote(diploid)\

Split sexes
Hermaphrodites
Sex reversal

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Hermaphroditism

A

Individual animal produces both gametes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Separate sexes

A

Male produces sperm and female produces eggs

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Asexual reproduction

A

Budding
Fragmentation
Parthenogenesis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Budding

A

New individuals arise from outgrowths of existing ones

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Fission

A

Splitting and separation of a parent organism into two individuals of approximately equal size

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Parthenogenesis

A

An egg develops without being fertilized

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Mixed

A

Both sexual and asexual, often influenced by environmental conditions

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Pituitary hormones are central to both female and male reproduction in all vertebrates
There are significant variations between animal reproduction

such as

A

seasonal vs continuous breeders
Cycles are controlled by Hormones whose secretion is regulated by environmental cues

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Hypothalamus important for reproduction too

why

A

Neurosecretory cells in hypothalamus release hormones in circulatory system that enter portal vessels and into the anterior pituitary

hormones trigger resproduction

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

In reproduction, the important hormones are

A

GnRH, FSH, and LH

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

GnRH

A

made by neurosecretory cells of the hypothalamus and goes into the blood, stimulates the anterior pituitary cells to release FSH and LH and depending on if you’re male or female, this stimulates estradiol production, testosterone production and do other things

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Ovulation

A

Release of mature eggs
Occurs at the midpoint of each cycle

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Why effect does climate change have on reproduction

A

It can decrease reproductive success because seasonal temperature is an important cue for reproduction

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Gonads

A

Organs that produce gametes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

In males what is the goal of the individual reproductvei cycle

A

spermatogenesis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

Follicle-stimulating hormone (FSH) is

A

a hormone that regulates sexual development and reproduction in both men and women

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

the target of FSH in males is

A

sertoli cells

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

sertoli cells

A

support and nourish developing sperm cells throughout the process of spermatogenesis, providing a suitable environment for maturation

21
Q

The targets of LH Luteinizing hormone are the

A

Leydig cells

22
Q

Leydig cells are primarily responsible for

A

producing testosterone, playing a crucial role in male sexual development, maintaining secondary sexual characteristics, and supporting sperm production

23
Q

There is an optimal level of testosterone
We keep it at a desired setpoint with

A

negative feedback

As testosterone is produced in the testes, it acts both locally to stimulate spermatogenesis but as a hormone it gets into the blood and travels everywhere
this reaches the hypothalamus through the blood and inhibits the hormones that are stimulating testosterone
- inhibits anterior pituitary and reduces LH and FSH and inhibit GnRH

24
Q

If you have low testosterone there is no testosterone feeding back to the hypothalamus so

A

there is no inhibition and thus you get an increase in GnRH production, increase in LH and FSH and get back to the optimum point

25
Q

Sertoli cells have another inhibitor

A

They make another hormone called inhibin which negatively regulates FSH production

26
Q

Spermatogenesis

A

Sperm production is continuous
We need stem cells that divide and commit to making sperm
We have a stem cell that commits to spermatogenesis and it will form primary spermicide and go through meiosis→ all four products go on to become sperm

27
Q

Oogenesis

A

Egg production starts during embryonic development but is arrested at prophase of meiosis I
This is called a primary oocyte

Every 28 days, starting from puberty, one primary oocyte will restart meiosis and then arrest at metaphase meiosis II
This is called a secondary oocyte
Fertilization stimulates the second meiosis
Results in one mature egg

28
Q

Reproductive cycle

A

28 day cycle
Have to do both Preparing and maturing egg and Preparing and maturing uterus

29
Q

Days 0-14

A

Hypothalamus releases GnRH which causes anterior pituitary to release FSH and LH

The target of these is the follicle cells

Follicle grows under the action of FSH/LH and estradiol starts to increase

Rising estradiol level stimulates endometrium proliferation in the uterus in preparation for implantation

Rising estradiol levels also stimulate GnRH release by the hypothalamus leading to spike in LH around day 14 that results in ovulation

30
Q

Day 15-28

A

LH stimulates the remaining follicle to form corpus luteum
The corpus luteum becomes a temporary steroid hormone producing gland, making the hormone progesterone
The combination of estradiol and progesterone inhibit GnRH release by the hypothalamus and LH and FSH levels will fall

different things occur based on if fertilization occurs or not

31
Q

If the fertilization does occur,

A

progesterone production by the corpus luteum persists and is essential for establishing and maintaining pregnancy by maintaining the thick lining of the endometrium

The continued inhibition of GnRH prevents oocyte maturation during pregnancy

32
Q

If fertilization does not occur,

A

the corpus luteum stops secreting progesterone and decays after approximately 10 days and the cycle starts again

33
Q

Oral contraceptives

A

Contain a combination of a synthetic estrogen and a synthetic progestin
They inhibit GnRH release by the hypothalamus and inhibit follicle maturation and ovulation
Progestin only pills are common

34
Q

What if fertilization does occur?

A

The fertilized egg must finish meiosis II before the two pronuclei fuse
First cleavage occurs about 24 to 30 hours after fertilization
The fertilized egg is carried down the oviduct to the uterus
Implantation in humans occurs about 7 days after fertilization

35
Q

Why do we maintain corpus luteum if fertilization occurs

A

6-10 days following fertilization, the embryonic cells called trophoblast start to produce the hormone human chorionic gonadotropin(hCG)
\
hCG has the same activity as LH and maintains the secretion of progesterone and smaller amounts of estradiol by the corpus luteum

36
Q

Mifepristone

A

In abortion pill
It is an antiprogesterone that will bind to and occupy progesterone receptors without activating them
This blocks endogenous progesterone from working

37
Q

As pregnancy progresses, the placenta starts to develop at about week 4

how are the mother and fetus connected

A

Maternal and fetal circulation are entirely different but there is a equivalent of exchange of capillaries
The placenta facilitates nutrient, gas, and waste exchange between the physically separate maternal and fetal circulations
Placenta connects to the fetus via the umbilical cord
Placenta is composed from both maternal and fetal tissues

38
Q

Start of labor

A

Uterine contractions
Something triggers it to begin
Placental degradation may be the cause
Estradiol will stimulate the presence of oxytocin receptors
Oxytocin will stimulate uterine contraction
Nerves in the uterine will stimulate more oxytocin
Prostaglandins hormones are being produced by the placenta which also stimulate uterine contraction

39
Q

Differences between spermatogenesis and oogenesis

A

Spermatogenesis is continuous in adult males

Oogenesis is a prolonged process in human females

In spermatogenesis the four products of meiosis develop into mature gametes\

In oogenesis meiosis produces unequal products with one daughter cell getting almost all the cytoplasm

Spermatogenesis occurs throughout adolescence and adulthood whereas oogenesis mitotic divisions occurs before birth and the production of mature gametes ceases at about 50

Spermatogenesis produces sperm in a continuous sequence whereas oogenesis has long interruptions

40
Q

Mammalian reproduction is governed by the coordinated actions of hormones from the

A

hypothalamus, anterior pituitary, and gonads

41
Q

Endocrine control of reproduction begins with the

A

Hypothalamus which secretes gonadotropin-releasing hormone (GnRH)

42
Q

GnRH directs the anterior pituitary to

A

Secrete the gonadotropins follicle-stimulating hormone(FSH) and luteinizing hormone(LH)

FSH and LH support gametogenesis by stimulating sex hormone production by the gonads

43
Q

What does the stimulation of FSH on sertoli cells do

A

It stimulates the cell located within the seminiferous tubules to nourish developing sperm

44
Q

What does the stimulation of LH on leydig cells do

A

LH causes leydig cells to produce testosterone and other androgens which promote spematogenesis in the tubules

45
Q

What two negative feedback mechanisms control sex hormone production in males

A

Testosterone regulates the blood concentration of GnRH, FSH, and LH through inhibitory effects on the hypothalamus and anterior pituitary

Inhibin , a hormone that is produced by sertoli cells in males, acts on the anterior pituitary gland to reduce FSH secretion

46
Q

There are two closely linked reproductive cycles in human females
Both are controlled by cyclic patterns of endocrine signaling

A

Ovarian cycle
uterine/menstrual cycle

47
Q

Ovarian cycle

A

Cyclic events in the ovaries
Once per cycle a follicle matures and an oocyte is released

changes in uterus

48
Q

In each menstrual cycle what occurs

A

The endometrium lining of the uterus thickens and develops a rich blood supply before being shed through the cervix and vagina if pregnancy doesn;t occur

mcdb1b (10 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions