LAB Final Part 1 (Reproductive) Flashcards
what types of sexual reproduction occur in the animal kingdom?
both sexual and asexual
the creation of offspring by fusion of male gamete (sperm) and female gamete (egg) to form a zygote
sexual reproduction
creation of offspring without the fusion of egg and sperm
asexual reproduction
what is an example of animal reproduction taking many forms?
sea slugs are both male and female, each one producing both eggs and sperm
how does a population only live out its members?
by reproduction, the generation of new individuals from existing ones
a simple form of asexual reproduction found only among invertebrates
budding
how do new individuals arise with budding?
from outgrowths of existing ones
a way many invertebrates reproduce asexually where the separation of a parent into two or more individuals of about the same size
fission
characteristics of budding (3) (OOS)
1) offspring grow from parents body
2) once a certain size offspring are released from parents
3) some species offspring remain attached
steps with fragmentation (2) (PE)
1) the parent’s body is broken into more than one piece
2) each piece regenerates to form new individuals is
does fragmentation happen on purpose?
no always
what must fragmentation be accompanied by?
regeneration
regrowth of lost body parts
regeneration
when an unfertilized egg produces an individual
parthogenesis
what do sexual females have compared to asexual females and what is that?
half as many daughters, it’s the “twofold cost” of sexual reproduction
despite the twofold cost of sexual reproduction, how do most eukarayotic species reproduce?
sexually
by producing offspring of varied phenotypes what may enhance reproductive success when environmental factors change rapidly?
sexual reproduction
what type of reproduction is expected to be most advantageous in stable, favorable environments
asexual
what do most animals exhibit reproductive cycles related to?
changing seasons
what are reproductive cycles controlled by?
hormones and environmental cues
the release of mature eggs at the midpoint of a female cycel
ovulation
since seasonal temperature is often an important cue in reproduction what can decrease reproductive success?
climate change
how can some oraganism produce depending on conditions?
sexually or asexually
what do several genera of fishes, amphibians and lizards reproduce only by a complex form of?
parthegenosis
what does parthenogenesis involve?
the doubling of chromosomes after meiosis
what do many animals find challenging?
finding a partner for sexual reproduction
a solution to finding a partner for sexual reproduction where each individual has male and female reproductive systems
hermaphroditism
how do hermaphrodites reproduce ?
two hermaphrodites can mate and some can self fertilize
what do individuals of some species undergo
sex reversals
what type of sex reversals do some species exhibit?
male to female reversals (certain oysters) and female to male reversals (coral reef fish)
the union of the egg and sperm play an important part in sexual reproduction
fertilization
when eggs shed by the female are fertilized by sperm in the external environment
external fertilization
what is required of external fertilization and why?
a moist environment so that the sperm can swim to the egg and prevent the gametes from drying out
in external fertilization when individuals cluster in the same area to release their gametes into the water at the same time
spawning
in some cases what’s responsible for external fertilization?
chemical signals trigger spawning in other environmental cues are respsonsible
sperm are deposited in or near the female reproductive tract and fertilization occurs within the tract
internal fertilization
what does internal fertilization require?
behavorial interactions and compatible copulatory organs
what does ALL fertilization require? (2) (CB)
1) critical timing
2) behaviorial interactions and compatable copulatory organs
what is fertilization often mediated by? (3) (EPC)
1) environmental cues
2) pheremones
3) courtship behavior
characteristics of ensuring survival of offsrping in internal fertilization? (4) (FHMP)
1) fewer gametes
2) higher surivial rate
3) mechanisms to provide protection of embryos
4) parental care for young
where do embryos of some terrestrial animals develop in? (3) (EPS)
1) egg with calcium
2) protein containing shells
3) several internal membranes
what do some other animals retain in internal fertilization?
the embryo, which develops inside the female
what does parental care ensure in many animals?
surivival of offspring
what must animals produce to produce sexually?
gametes
some species have these organs that produce gametes
gonads
what do some simple systems not have?
gonads but gametes form from undifferentiaed tissue
what do more elaborate systems include sets of?
accesory tubes and gland
what do accessory tubes and glands do in more elaborate systems?
nourish and protect gametes and developing embryos
what do most insects have?
separate sexes with complex reproductive systems
many female insects have this, when a sperm is store during copulation
spermatheca
a common opening between the external environment and the digestive, excretory and reproductive systems
cloaca
what is a cloaca common in?
nonmammalian verterberates
what do mammals usually have?
a separate opening
what is relatively rare among animals?
monogamy
what do males and/or females of some species have to decrease the chance of their mate mating with another individual?
evolved mechanisms
what can females sometimes influence with their mates?
the relative reproductive success
one male mates with many females
polygamy
one female mates with many males (sandpiper)
polyandry
males and females mate with multiple partners
promiscuous
each individual has both male and female reproductive systems
hermaphroditc
what are example of hermaphrodotic animals?
clams, seas slugs and barnacles
in humans what are the male external reproductive organs?
scrotum and penis
in humans what are male internal reproductive organs? (3) (GAD)
1) gonads (produce sperm and horomes)
2) accessory glands (secrete products needed for sperm movement)
3) ducts (carry sperm and glandular secretions)
male gonads that consist of highly coiled tubes surrounded by connective tissue
testes
where does sperm form in human males?
in these semineferous tubules
in human males what produces hormones and are scattered between the tubules?
leydig cells
what can the production of normal sperms NOT occur at?
the body temperature of most mammals
where the testes of may mammals are held outside the abdominal cavity, where the temperature is lower than in the abdominal cavity
scrotum
where does sperm pass into from the semifernous tubules in the testes in human males?
the epididymis
during ejaculation in human males what is sperm propelled through and where does it exit?
the muscular vas deferens and the ejaculatory duct and then exits the penis through the uretha
what is semen composed of?
sperm plus secretions from three sets of accessory glands
what contributes to about 60% of the total volume of semen?
two seminal vesicles
secretes its products directly into the urethra through several small ducts
prostate gland
secretes a clear mucus before ejaculation that neutralizes acidic urine remaining in the urethra
bulbourethral glands
in female humans what are the internal organs that carry the gametes and house the embryo and fetus?
a pair of gonads and a system of ducts and chambers that carry gametes and house the embryo and fetus
the female gonads that lie in the abdominal cavity
ovaries
what does each ovary contain?
follicles
what does the follicles consist of?
an oocyte surrounded by support cells
a partially developed egg
oocyte
how does the egg travel from the ovary to the uterus?
via an oviduct or fallopian tube
what conveys the egg to the uterus?
cilia in the oviduct
what else is the uterus called?
the womb
the uterus lining with many blood vessels
endometrium
where the uterus narrows and opens into the vagina
cervix
a muscular but elastic chamber
vagina
functions of the vagina (2) (RB)
1) repository for sperm during copulation
2) birth canal
where does the vagina open to the outside at?
the vulva
what does the vulva consist of?
1) labia majora
2) labia minora
3) hymen
4) clitoris
what is not part of the reproductive system but are important to mammalian reporoduction?
mammary glands
what are within the mammary glands?
sacs of epithelial tissue secrete milk
production of gametes
gametogenesis
the formation of sperm and is continous and prolific
spermatogenesis
how many sperm are produced per day and how long does it take for them to develop?
hundreds of million and takes about 7 weeks to develop
the development of a mature egg. is a prolonged process
oogenesis
what forms in the female embryo but don’t complete their development until years or decades later
immature eggs
3 ways spermatogenesis differs from oogenesis (ASS)
1 )all four products of meiosis develop into sperm while only one of four become an egg
2) spetmatogenesis occurs throughout adolescence and adulthood
3) sperm are produced continously without the prolonged interuprtion in oogenesis
what is human reproduction coordinated by? (3) (HAG)
1) hormones from the hypothalamus
2) anterior pituitary
3) gonads
secreted by the hypothalamus and directss the release of FSH and LH from the anterior pituitary
Gonodotropin-releasing hormone (GnRH)
what regulates processes in the gonads and the production of sex hormones?
FSH and LH
what are the main sex hormones?
steroid hormones
what is the main androgen?
testrosterone
what does estrogens consist mainly of?
estradiol and progesterone
what are some of the functions that sex hormones serve in addition to gamete production? (2) (SD)
1) sexual behavior
2) the development of primary and secondary sex characteritsitcs
in male humans what promotes activity in sertoli cells which nourish developing sperm?
FSH
in male humans what regulates leydig cells, which secretes testosterone and other androgens which in turn promote spermatogenesise events
LH
in female humans what are the secretion of hormones and the reproductive event they regulate?
cyclic
what happens prior to ovulation?
the endometrium thickens with blood vesseles in preperation for the embryo implantation
if an embryo does not implant in the endometrium, what happens?
menstruation occurs where the endometirum sheds
what closely links the two cycles of female reproduction?
hormones
what are the changes asscoiated with female reproduction?
1) changes in the uterus define the menstrual cycle (also called uterine cycle)
2) changes in the ovaries define the ovarian cycle
during the ovarian cycle what is there a sequential release of that stimulates follicle growth?
GnRH and FSH and LH
what characterizes the follicular phase of the ovarian cycle?
follicle growth and an increase in the hormone estradiol
what does the follicular phase end and what happens after?
at ovulation, the secondary oocyte is released
what is occuring during the luteal phase in human females after ovulation?
the follicular tissue left behind is stimulated to transform into the corpus luteum
what does the corpus luteum secrete that exert negative feedback on the hypothalamus and pituatary?
progesterone and estradiol
what happens if no embryo implants the endometrium>
a new cycle begins
what type of location can cells of the uterine lining sometimes migrate to?
an abnormal or ectopic location
a disorder where swelling of cells in repsonse to hormone stimulation
endometriosis
after about 500 cycles, it occurs where the cessation of ovulation and menstruation occur
menopause
what is very unsual among animals?
menopause
what may menopause have evolved for?
to allow a mother to provide better care for her children and grandchildren
menstrual cycle characteristics (2) (ES)
1) the endometrium is shed from the uteris in a bleeding called mensturation
2) sexual receptivity is not limited to a time frame
estrous cycles of most mammals (3) (ESL)
1) the endometirum is reabsorbed by the uterus
2 )sexual receptivity is limite to a “heat” period called estrus
3) the length and frequency of estrbous cycles vary from species to species
in placental animals what develops fully withi the mother’s uterus?
the embryo
fertlization of an egg by a sperm in the oviduct
conception
the resulting zygote begins to divide by mitosis
cleavage
a ball of cells with a central cavity given rise from a disvision of cells
blastocyst
after blastocyst formation what happens/
the embryo implants into the endometrium
the condition of carrying one or more embryos in the uterus
pregnancy or gestation
during pregnancy in other species what correlate?
with body size and maturity of young at birth
what are the roughly nine months of human gestation divided into?
3 trimesters of equal length
are all embryos capable of completing development?
no
what do many embryos spontaneously stop development due to
chromosomal or other developmental abnormalities
what happens rarely where a fertilizied egg lodes in the fallopian tube?
ectopic pregnancy
what does the splitting of the embryo during the first month of development result in?
genetically identical (monozygotic) twins
what does the release and fertilization of two eggs result in?
fraternal and genetically distinct (dizyogtic) twins
the deliberate prevention of pregnancy
contraception
3 methods of contraception (PKP)
1) preventing release of egg and sperm
2) keeping sperm and egg apart
3) preventing implantation of an embryo
when one refrains from intercourse when contreception is most likely and has a pregancy rate of 10-20%
rhythm method or neutral family planning
what is an unrealiable method to interupt coitus?
the withdraw of the penis before ejaculation
what are some barrier methods which has a pregnancy rate of less than 10% (CD)
1) a condom that fits over the penis
2) a diaphragm insterted into the vagina before intercourse
inserted into the uterus and interfere with fertilization and implantation, the pregnancy rate is less than 1%
intauterine devices (IUDs)
horonal contraceptive with a pregnancy rate of less than 1%
female birth control pills
permanent prevention of the release of gametes
sterilization
2 types of sterilization
1) tubal ligation that ties off the oviducts
2) vasectomy that ties off the vas deferns
termination of pregnancy
abortion
what occurs in one-third of all pregancies?
spontaneous abortion or miscarriage
what does the drug RU486 and when?
it terminates a pregnancy nonsurgically within the first 7 weeks
ways to detect disorders during pregancny (2) (AU)
1) amniocentesis and chronic villus sampling (invasive)
2) ultrasound (non-invasive)
what does genetic testing of the fetus pose?
ethical questions and can present parents with difficult decisions
where are almost all detectable disorders untreatable?
in the uterusand many cannot be corrected afterbirth
among the preventable causes of infertility what are most significant?
STDs
mixes eggs with sperm in culture dishes and returns the embryo to the uterus at the eight-cell stage
In vitro fertilization (IVF)
what can also be injected difrectly into the oocyte?
sperm or sperm nuclei
