Reproductive Flashcards
English physiologist who founded experimental physiology and published a treatise on reproduction
William Harvey
What is the indivation of william harvey regarding life
All life developed from the egg
Reproduction is not restricted to eggs and sperm but can also be by
Fission, budding, fragmentation
Two modes of reproduction
Asexual and sexual reproduction
enhances long-term survival for the species.
Reproduction
Reproduction is one of the ______ properties of life
Ubiquitous
Is the production of new individuals without gametes.
Asexual Reproduction
How many parents does asexual reproduction need?
One parent
Genetically identical offspring are produced
Clones
Asexual reproduction is widespread in?
Bacteria, unicellular eukaryotes, invertebrae phyla
Common among bacteria and protozoa where the parent divides by mitosis into two parts
Binary fission
Offspring of binary fission?
Clone
Binary fission can be in what directions?
lengthwise or transverse
Cytoplasmic division then produces many daughter cells simultaneously
Multiple fission
Nucleus divides repeatedly
schizogony
Is a type of schizogony found in some parasitic unicellular
eukaryotes
Sporogony
Unequal division of an organism where bud is outgrowth of the parent
budding
New individual arises from cell aggregation surrounded by a resistant
capsule
Gemmulation
resistant capsule
gemmule
What animal does gemmulation commonly occur
freshwater sponges
What animal does budding commonly occur?
Cnidarians and animal phyla
Multicellular animal breaking into many fragments that become a new
animal
fragmentation
What animal does fragmentation commonly occur?
anemones, hydroids
is the production of new individuals from
gametes.
sexual reproduction
how many parents in sexual reproduction?
2
What unites in sexual reproduction at what is its outcome?
germ cells, zygote
Produces offspring from union of gametes from two genetically different
parents
Bisexual Reproduction
Organs that produce germ cells called gametes
gonads
Individuals are male or female
dioecious
is large with stored yolk and generally nonmotile— made in the ovary.
ovum
usually small, motile, and more numerous— made in the testis.
Spermatozoa
Occurs in the gonads and has double cell division
meiosis
What does meiosis produces?
4 haploid cells
Two haploid cells combine and restores the diploid chromosome number in the zygote
fertilization
how does zygote divides?
mitosis
Special type of sexual reproduction since it occurs in unicellular creatures that can do both sexual and asexual
types of reproduction
conjugation
Conjugation occurs in unicellular creatures that can do both sexual and asexual types of reproduction like like
Paramecium
Conjugation has no gametes used but exchange nuclear material is via?
cytoplasmic merger or connection tubes
Does conjugation has distinct sex/gender in the population
no
which has many offspring, dioecious or monoecious?
monoecious
occurs when one individual has both male and female organs.
hermaphroditism
other term for having both female and male?
monoecious
what doe hermaphroditism prefers when being fertilized
exchange gametes with other members of the same species
Same organism with both male and female sex organs
simultaneous hermaphroditism
A genetically programmed sex change occurs with an individual organism
sequential hermaphroditism
is the development of an embryo from
unfertilized egg
parthenogenesis
is a variant of meiotic parthenogenesis.
haploidiploidy
type of hermaphroditism where life begins as either male or female then changes to become the
opposite sex/gender
sequential hermaphroditism
occur when development proceeds after male and female nuclei fail to unite after fertilization.
parthenogenesis
Two types of parthenogenesis
ameiotic parthenogenesis
meiotic parthenogenesis
What type of cell division occurs in ameiotic parthenogenesis?
mitosis
What type of cell division occurs in meiotic parthenogenesis?
meiosis
what animals does haploidiploidy occurs?
bees, wasps, and ants
Describe the activation of the sperm in ameiotic parthenogenesis
NO fusion of sperm to the egg
but activates it
Describe the activation of the sperm in meiotic parthenogenesis
no fusion, no activation
In some species, the haploid egg returns to a diploid condition by chromosomal duplication or autogamy
Meiotic parthenogenesis
who controls whether the eggs are fertilized or unfertilized
queen
in haploidiploidy fertilized eggs become
female workers / queen
In haploidiploidy unfertilized eggs develop into
drones (males)
What do you call rejoining of haploid nuclei?
Autogamy
In crowded habitats, _____________ is intense and ____________ prevents extinction.
natural selection, diversity
Nonreproductive body cells, become differentiated, function, and die before or with the animal
somatic cells
Form gametes, provides a continuity of life between generations
germ cells
What are gametes?
sperm and egg cells
In many invertebrates, germ cells develop directly from?
somatic cells
Male determining gene
sex-determining region Y
A gene activated by sex determining region where it drives production of
Sertoli cells .
SOX9
necessary for the support, protection, and nourishment of developing sperm
sertoli cells
Secretes testosterone which, with dihydrotestosterone (DHT), masculinizes the fetus
Testis
is indirectly responsible for masculinization of the brain
testosterone
determines brain organization for male-typical behavior
estrogen
what does testis secretes to masculinized the fetus
testosterone and dihydrotestosterone
Testosterone is enzymatically converted to ____ in the brain
estrogen
In rats a _________ binds to estrogen and prevents it from reaching the
developed brain
blood protein
In humans, there may be a ________ of estrogen receptors in the female brain
low concentration
Determined by chromosomes in most vertebrates like mammals and fish
gonadal sex
gonadal sex is _________
gene dosage dependent
Depends on hormones that is affected by nongenetic factors
phenotypic and behavioral sex
What are non genetic factors
temperature of incubation and
social behavior
Production of mature gametes
gametogenesis
Formation of sperm or male gametes
spermatogenesis
Types of gametogenesis
spermatogenesis and oogenesis
where does the formation of sperm occurs?
Seminiferous tubules of the
testis
Formation of eggs or female gametes
oogenesis
where does the formation of egg occurs?
within the follicles of the ovaries
provide nourishment to the sperm cells
sertoli cells
Undergoes the first meiotic division and what is its outcome?
primary spermatocytes, secondary spermatocytes
Found in the outermost layer of the seminiferous tubules
spermatogonia
Spermatogonia:How does it divide and what its outcome?
mitosis, primary spermatocytes
The four spermatids are transformed into _____
4 spermatozoa
Undergoes the second meiotic division and what is its outcome?
secondary spermatocytes, 2 spermatids
Most are very small—size varies from 50 µm to 2 mm
spermatozoa
true or false: All sexually reproducing animals have more eggs than sperm to increase chances of fertilization rates and maximize survival
false
diploid / haploid? secondary spermatocytes
haploid
diploid / haploid? spermatogonia
diploid
diploid / haploid? spermatozoa
haploid
diploid / haploid? primary spermatocytes
diploid
diploid / haploid? spermatids
haploid
When spermatid is modified as it transforms to spermatozoa, what happens to cytoplasm?
lost
When spermatid is modified as it transforms to spermatozoa, what happens to haploid nuclei
condenses to head
When spermatid is modified as it transforms to spermatozoa, what is formed and added to power the tail
midpiece, mitochondria
provides locomotion for the sperm
whip-like flagella tail
enzyme that allows sperm to penetrate
follicular cells around the egg
hyaluronidase
Sperm head of nearly all metazoans contain an
acrosome
Initially diploid and increase in number by mitosis
oogonia
is the production of gametes in the ovaries.
oogenesis
oogonia stop dividing and then increase in size to form?
primary oocytes
Before first meiosis, parental chromosomes meet in pairs forming
homologues
primary oocytes
Primary oocytes undergoes first meiotic division producing
secondary oocytes, polar bodies (nonfunctional cells)
diploid / haploid? ootid
haploid
Each primary oocyte only forms
one ovum
Develops into a functional haploid ovum
ootid
secondary oocytes undergoes second meiotic division producing
one large ootid and a
second polar body
diploid / haploid? secondary oocytes
haploid
diploid / haploid? oogonia
diploid
diploid / haploid? primary oocytes
diploid
Development is arrested in in what phase of meiosis as in the primary oocyte phase
prophase I
meiosis resumes when?
ovulation or after fertilization
what develops during each menstrual cycle
secondary oocytes
Meiosis II completed after fertilization when
sperm penetrates the ovum
Egg maturation in animals involves the deposition of
yolk
Accumulation of ________ and ________ cause eggs to grow massively beyond normal cell size.
yolk granules and nutrients
Lay eggs outside the body, –some animals abandon eggs; others provide extensive care
oviparous animals
type of fertilization in oviparous
internal or external
Retain eggs in their body and essentially all nourishment derived from the yolk
Ovoviviparous animals
type of fertilization in ovoviviparous
internal
Give birth to young in a more advanced stage of development
viviparous animals
in viviparous animals where does embryos continuously derive nourishment from
mother
type of fertilization in viviparous
internal
Primary organ of reproductive system and what it produces
gonads - sperm cells, egg cells, and sex hormones
What includes in the accessory organs
Gonoducts, storage organs, transfer systems, yolk glands, and
placenta
this type of organ assist gonads in formation and delivery of gametes and may support embryos
accessory organ
Components of sexual systems
primary organs and acessory organs
Sperm from the _____ pass through ____ and is stored in _________ until ___________
testes, sperm ducts, seminal vesicles, ejaculation via penis
Ovaries form from ____; release __________ through ________
egg tubes, mature ova, oviducts
Ova stay in ________ connected to _____ until release by __________
genital chamber, genital bursa, ovipositor
Invertebrates with external fertilization
has gametes arise from cells that proliferate along _________
body cavity linings
have no permanent organs but can release mature gametes through different coelomic openings, nephridial
ducts, and various body wall ruptures
polychaete annelids
reproductive and excretory systems form the
urogenital system
In male fishes and amphibians the ____________ drains the kidney and transports sperm
opisthonephric duct
In male reptiles, birds, and mammals the kidney develops its own independent duct
ureter
is a common chamber for all intestinal, reproductive, and excretory product
cloaca
Sperm develop within the
seminiferous tubules
in females, the _____ is an independent duct
oviduct
between lobules of testis secrete
testosterone
leydig cells
nourish the developing sperm
sustentacular cells (sertoli cells)
Testes are located in a _________
saclike scrotum
____ temperature of scrotum vital to normal sperm production
lower
pathway of sperm
Seminiferous tubules, vasa efferentia, epididymis, vas deferens, urtehra
Small tubes connected to the epididymis
vas efferentia
coiled region where sperm maturation occurs
epididymis
Carries sperm from the epididymis to the urethra also known as ejaculatory duct
vas deferens
Can carry urine and sperm through the penis
urethra
the male copulatory organ
penis
Secrete a thick fluid containing nutrients for sperm
seminal vesicles
Some mammals have a bony structure called __________ to help with
rigidity and sperm transfer
baculum
add secretions to male duct system to
form seminal fluid
accessory sex glands
Secretes a milky, slightly alkaline solution that counters acidity of vagina
prostate gland
Secretions provide lubrication and remove traces of urine from urethra
bulbourethral gland
what does ovaries produce?
ova
Mature ova from ovaries enter funnel-like
fallopian tube
female sex hormones—
estrogen and progesterone
Terminal portion of oviduct expands into a
muscular uterus
__________ enlarges and ruptures through the _______ to release ________
mature follicles, wall of ovary, secondary oocytes
Walls of uterus establish close vascular association with embryonic
membranes through a ____
placenta
Average of _______ per year with each ovary alternating the release
of eggs
13 oocytes
Ovum then released into the
pelvic cavity
oviducts is lined with?
cilia
Propel the ovum away from the ovary and into the uterus
oviduct
Site of implantation
uterus
Specialized lining with highly vascular tissues of the uterus
endometrium
Thick smooth muscle layer of the uterus
myometrium
Muscular tube that receives the penis and serves as birth canal
vagina
Region of the uterus that extends and connects into the vagina
cervix
External female genitalia
vulva
enclose urethral and vaginal openings
Labia majora and labia minora
is a small erectile organ and homologous to the penis of males
clitoris
regulates release of anterior pituitary gland hormones
Hypothalamus region of the forebrain
Vertebrate reproduction is usually a
seasonal or cyclic activity
Cyclic reproductive patterns of female mammals
estrous cycle and menstrual cycle
anterior pituitary gland hormones
stimulate the following
gonadal tissues, accessory sex organs, and secondary sexual characteristics
Females receptive to males only during brief periods of “in heat”
estrous cycle
—characteristic only of anthropoid primates like monkeys, apes, and humans
menstrual cycle
Females are receptive to males throughout the cycle with increased
receptivity during ____
ovulation
At the end of the menstrual cycle, the outer layer of __________ breaks down and is discharged into _____
endometrium, menstruation
True or false? estrous cycle has menstruation
false
Development of female accessory sex structures:
oviducts, uterus, and
vagina
Both function to prepare uterus for developing embryo
estrogen and progesterone.
Estrogen and Secondary Sex Characteristics
- Skin or feather coloration
– Bone development
– Body size
– Initial development of mammary glands
2 Anterior pituitary gonadotropins:
- Follicle-stimulating hormone (FSH)
- Luteinizing hormone (LH)
Hypothalamus secretes ________ which governs release of FSH and LH
gonadotropin releasing hormone
Environmental factors like______,____ and _____ that may affect reproductive cycles
light, nutrition, and stress
Estrogens and progesterone provide feedback to
hypothalamus and anterior pituitary
In male vertebrates the testes produce
testosterone and dihydrotestosterone
Secondary sex characteristics in male
- Male plumage and pelage coloration
- Bone and muscle growth
- Antlers in deer and other mammals
- Thickening of the vocal cords and deepening of voice in humans
- Male sexual behavior
Male Sertoli cells and female ovaries secrete a protein called
inhibin
Testosterone and DHT feed back to the
hypothalamus and anterior pituitary
Regulates FSH secretion by negative feedback
inhibin
zygote divides by _____ to form a ______
mitosis, blastocyst
In birds and some mammals ____ may be discovered
gonadotropin-inhibiting hormone (GnIH)
Forms a zygote and travels to uterus
fertilization
Implantation in about
6 days
Blastocyst reaches uterus and embeds in the
endometrium
Implanted embryo now has many layers:
trophoblast, amnion, embryo cell mass, chorion
Surrounding cell layer that produced enzymes to allow for implantation
Trophoblast cells
Cells forming a sac that is used for protection
amnion
Actively dividing cells of the zygote
embryo cell mass
Becomes placenta (partly)
chorion
During pregnancy, elevated ____ and ________ depress inhibitory signal and this appears in the blood
progesterone and estrogen
Two hormones needed for mammary glands to secrete milk
Prolactin and human placental lactogen
PRL also secreted by ______ during pregnancy
placenta
what produces prolactin
anterior pituitary
other term of Human placental lactogen
human choronic somatomammotropin
aids PRL in preparing the mammary glands for secretion
human placental lactogen
HPLt ogether with_________, stimulates increase in nutrients in the mother to provide for embryo
maternal growth hormone
The placenta also secretes ______ and ______
b-endorphin and endogenous opioids
The placenta also synthesizes the peptide hormone
relaxin
Dilates the _____ in preparation for delivery
cervix
Allows expansion of pelvis by increasing the flexibility of
pubic symphysis
Three Stages of Childbirth
dilation, expulsion, placental delivery
Baby is forced out of the _______ and through the _________
uterus, vaginal birth canal
In the first stage ____ enlarges and ____ruptures due to pressure from baby
cervix, amniotic sac
_________is normally expelled within __ minutes after baby was born
placenta, 10
other term for birth
parturition
