Ch. 46 - Animal Reproduction Flashcards
big ideas: male/female reproductive A&P, hormone effects, menstrual cycle, sperm can live for 5 days
what type of genetic offspring is produced by asexual reproduction?
a genetically identical clone
what type of genetic offspring is produced by sexual reproduction
a genetically unique offspring
what are some advantages of asexual reproduction?
-fast
-no mate needed
-good in a stable environment
what is parthenogenesis?
a form of asexual reproduction where an unfertilized haploid egg grows into a haploid adult
what is hermaphroditism?
a form of sexual reproduction where one individual produces both types of gametes
what is sequential hermaphroditism?
a form of sexual reproduction where one individual changes sex at some age
what is the function of the seminiferous tubules?
to produce sperm
what is the function of interstitial cells?
to surround the seminiferous tubules of the testes and secrete testosterone
what is the function of the sustentacular cells?
to secrete inhibin and ABP from within the seminiferous tubules
what three cells/structures are within the testes?
-seminiferous tubules
-sustentacular cells
-interstitial cells
what is the structure of a sperm?
-an acrosome with enzymes to break into egg
-head contains DNA
-a midpiece with mitochondria
-flagella made of microtubules for swimming
what is the epididymis?
the site of sperm maturation and storage until ejaculation
what is the vas deferens?
a muscular tube that moves sperm to the prostate gland during ejaculation
what are seminal vesicles?
two glands that secrete semen, secretions include fructose, clotting factors, and prostaglandins for uterine contractions
why do sperm cells need fructose in semen?
to allow them to undergo cellular respiration
what is the location of the prostate gland?
located just below the bladder & surrounds the urethra
what is the function of the prostate gland?
to secrete semen into the urethra, secretions include clotting factors, enzymes, and prostaglandins
what is the location of the bulbourethral gland?
under the prostate gland
what is the function of the bulbourethral gland?
to produce pre-ejaculate, which is a basic secretion to neutralize the acidity of the vagina
what is the function of the urethra? where does the urethra start?
to expel urine / ejaculate
urethra starts in the prostate gland
what is the structure of the ovary?
-the ovary contains follicles with immature eggs
what is the function of the ovary?
to produces eggs for ovulation and to secrete and produce estrogen and progesterone
what is a follicle?
cells surrounding the developing ovum
what are the uterine tubes?
oviducts lined with ciliated cells that move the egg towards the uterus
what are the two linings of the uterus?
endometrium: the inner lining which sloughs monthly
myometrium: smooth muscle that grows with pregnancy
what is the cervix?
the opening to the uterus, covered with a protective mucus plug
what is the corpus luteum?
a temporary collection of cells that secretes estrogens and progesterone during ovulation
how are sperm cells formed?
-a primary spermatocyte (2n) undergoes meiosis to produce four 1n sperm
what is spermatogenesis?
the production of sperm cells
what are the three main reproductive hormones used in the body?
GnRH - released from hypothalamus, which activates:
FSH and LH - released from anterior pituitary
what are the effects of LH in men?
-matures the male reproductive system & causes puberty by causing interstitial cells to secrete testosterone
what are the effects of LH in women?
-stimulates the endometrium to store nutrients by causing the corpus luteum to secrete progesterone
what are the effects of FSH in men?
-acts on sustentacular cells, which secrete inhibin and ABP, which activate testosterone and turn off FSH secretions
what are the characteristics of the menstrual cycle?
-occurs in primates; endometrium is sloughed monthly
-ovulation is “hidden”
what are the characteristics of the estrous cycle?
-occurs in non-primate mammals; overt ovulation and receptivity
-endometrium is not sloughed and occurs fewer times per year
what is the function of FSH in female reproduction?
acts on follicular cells to secrete estrogen. stimulating the endometrium to grow
what two components make up the sexual cycle?
the ovarian cycle + the menstrual cycle
what is the function of the follicular cells during pre-ovulation?
the follicle cells secrete estrogens and eventually become the corpus luteum once the ovum is released, which secretes progesterone post ovultation
where does fertilization occur?
in the uterine tube, near the ovary
what hormone is secreted by a fertilized zygote?
HCG / human chorionic gonadotropin
what is the function of human chorionic gonadotropin?
-takes over the role of LH to keep the corpus luteum and endometrium of the uterus alive and not sloughed
what occurs to the fertilized egg 1-2 weeks after fertilization?
the egg implants in the endometrium as a blastocyst
what is the role of the placenta?
to secrete estrogen and progesterone
what is the function of progesterone?
to suppress development of new follicles and support the endometrium
what is the function of estrogen?
to cause negative feedback of GnRH, as well as stimulate tissue growth in the fetus and mother
