Bio 30 Final review unit B/C1 Flashcards
What is present in semen?
-Sperm: Male gonads
-Fructose solution: secreted from the seminal vesicles to nourish sperm
-Alkaline buffer: secreted from the prostate to protect sperm from the acidic vagina
-mucous fluid: secreted from Cowpers gland prior to ejaculation to clear urethra
What produces each part of the semen
-Cowpers gland: mucous
-Prostate: alkaline buffer
-Seminal vesicles: Fructose solution/ prostaglandin(stimulates uterine contractions O
-Testes: sperm
What are the four phases of the menstrual cycle?
-Flow phase: the beginning of the cycle, shedding of the endometrium lining(menstruation), progesterone/estrogen levels are low.
-Follicular phase: FSH stimulates the development of the follicle, Development of follicles within the ovary, follicle will secret estrogen
-ovulatory phase: LH will stimulate ovulation, secondary oocyte bursts from the ovary and follicular cell will become the corpus luteum, estrogen levels will drop
-luteal phase: corpus luteum forms and the endometrium lining thickens, corpus luteum secretes progesterone and estrogen, if fertilization does not occur the corpus luteum will dissolve and the cycle will repeat
What days correspond to the four phases?
Days 1-5: Flow phase
Days 6-13: follicular phase
Day 14: Ovulatory phase
Day 15-28: Luteal Phase
What are the hormones doing in each of the four phases?
-Flow phase: low progesterone and estrogen levels signal the brain to secrete FSH and begin menstruation
-Follicular phase: FSH causes follicles to develop and secrete estrogen, estrogen will cause a decrease in LH and FSH levels until days 10-12 when it will cause LH and FSH production to ramp up (positive feedback)
-Ovulatory phase: A spike in LH will cause ovulation, the follicle will no longer secrete estrogen so estrogen levels will drop
-Luteal phase: Corpus luteum will secrete progesterone and estrogen, causing those levels to rise
What are the male hormones and where are they secreted from? What is the function of these hormones and where do they target?
-Testosterone: Produced in the interstitial cells of the testes, targets most cells, responsible for stimulating spermatogenesis, causing muscle growth, increasing sex drive, and developing male secondary sex characteristics
-FSH: produced by the pituitary, targets the testes, stimulates the Sertoli cells in the testes to help produce sperm in the seminiferous tubules
-LH: produced by the pituitary, targets the testes, stimulates the production of testosterone in the interstitial cells of the testes
What is the function of the placenta?
-Act as the lungs, kidneys and small intestine of the fetus. This is done via diffusion of important nutrients and gasses, along with wastes, from the maternal to the fetal blood across the placenta
What is the function of the amniotic sac?
The fluid-filled sac that insulates and protects the developing fetus
What is the function of the umbilical cord?
allows the diffusion between the maternal blood and fetal blood to take place
What is the general order of events in fetal development?
fertilization - zygote -3 to 6 days- blastocyst - implantation - gastrulation - embryonic development - Formation of Amnion, Chorion layers, yolk sac, and allantois - formation of placenta and umbilical cord - fetal development(CNS, Heart, Limbs, Ear, eyes, palet, teeth, genitals
What is the function of the chorion layer, and what two hormones does it secrete?
The chorion layer secretes HGC which supports the corpus luteum until the placenta develops. This keeps progesterone levels high
What two hormones does the placenta secrete and why?
The placenta secretes progesterone and estrogen to prevent uterine contractions, keeping the pregnancy
What do the two rounds of meiosis do?
Round 1: This is considered a reduction division because during this stage the chromosome number is halved (2n-46)-(2n=23)
Round 2: This round is considered an equational division because the chromosome number does not change. This stage serves to separate the sister chromatids of the daughter cells in phase one so that final products are single-stranded (2n=23)-(n=23)
What is produced from the ectoderm?
Skin, Hair, fingernails, sweat glands, nervous system, brain, lens, retina, cornea, inner ear, cochlea, semi-circular canals, teeth, the inner lining of the mouth
what is produced from the endoderm?
Liver, pancreas, thyroid, parathyroid, bladder, the lining of the digestive system, the lining of the respiratory system
what is produced from the mesoderm?
Muscles, blood vessels and blood, kidneys and reproductive structures, connective tissues, cartilage, bones
When a zygote turns into a blastocyst, what type of cell division is used?
Mitosis
What is a teratogen, and when do they have the biggest impact? What causes teratogens (environmental or genetic factors)?
A teratogen is an agent that produces malformations in a fetus. their destructive power is directly related to the critical growth periods of the fetus. they can be both environmental and genetic and include things like: German measles, drug/alcohol use, hypertension and many more
What are the female hormones, and what are their functions?
-Estrogen: produced in the follicle of the ovaries, targets most cells, initiates secondary sex characteristics in females at the start of puberty, and Thickens/develops the endometrium lining.
-Progesterone: produced by the corpus luteum, targets most cells, firms the cervix, prevents ovulation, prevents uterine contractions
-FSH: produced by the pituitary, targets the follicle, stimulates the follicle to develop in the ovary
LH: produced by the pituitary, targets ovaries, stimulates ovulation, maintains the corpus luteum
How do you identify sex on a karyotype? Nondisjunction? trisomy or monosomy?
To identify sex, you must look at the x and y chromosomes; if there are 2 x chromosomes the person is female, if there’s an x and a y they are male. To identify nondisjunction, look at all the chromosome pairs, if any have an extra trisomy has occurred, if any are missing monosomy has occurred
What are the general phases of meiosis and mitosis?
IP-MAT
Interphase, prophase, metaphase, anaphase, telophase, cytokinesis
(miosis will have I or II following the phase)
What is spermatogenesis?
A process in which sperm develop from a diploid germ cell (2n=46) in the seminiferous tubules of the testes. beginning with a primary spermatocyte that will go through two rounds of meiosis to produce four haploid daughter cells (spermatids) which will continue to develop
what is oogenesis
A process in which a germ cell called a primary oocyte will go through two rounds of meiosis. this will produce four haploid daughter cells(n=23)- one egg and three polar bodies
What are the differences between spermatogenesis and oogenesis
-Spermatogenesis is the formation of sperm whereas oogenesis is the formation of the ova
-Spermatogenesis occurs in the testes whereas oogenesis occurs in the ovaries
-Spermatogenesis is a continuous process, oogenesis is a finite process
-Spermatogenesis produces mobile gametes, oogenesis does not
-Spermatogenesis divides cytoplasm equally, oogenesis does not
What are the female sex organs and their functions
-Ovary’s: Secrete hormones, protect and release eggs
-Fallopian tubes: connect ovaries to the uterus, site of fertilisation, fertilized eggs pass to the uterus
-Uterus: Hollow muscular organ located between the bladder and rectum, Fertilised eggs attach to the lining of the uterus
-Endometrium: Innermost lining of the uterus, Shedding of this lining happens during the menstrual cycle, site of implantation
-Cervix: cylinder-shaped neck of tissue that connects the vagina to the uterus
-Vagina: Connects the uterus to the outside of the body
What path does semen leave the body?
1.Testes/epididymis
2. Vas deferens: carries sperm from the testes to the ejaculatory duct
3. Seminal vesicles: secrete fructose solution into semen
4. prostate: secretes alkaline buffer
5. Ejaculatory duct
6. Urethra
What diffuses from the maternal blood to the fetal blood across the placenta
Vital gasses: Mother to fetus/fetus to mother
Waste materials: Fetus to mother
Nutrients: Mother to fetus
What hormones are involved in birth, what are their functions?
Oxycontin: stimulates uterine contractions
relaxin: relaxation of the pelvic ligaments allowing the cervix to widen/dilate
What are the general steps of IVF
- Egg production stimulated by hormone therapy
- eggs retrieved from the ovary
- sperm sample provided
- Eggs and sperm combine to allow fertilization
- fertilized eggs introduced into the uterus
How does nondisjunction occur?
Nondisjunction occurs when two homologous chromosomes move to the same pole during anaphase I or when two sister chromatids move to the same pole in anaphase II
What are the male secondary sex characteristics
Body/facial hair, pubic hair, enlarged larynx(Adam’s apple), enlarged stature, heavier skull and bone structure
What are the female secondary sex characteristics?
enlargement of breasts, body hair, widening of the hips, beginning of menstrual cycle
What parts make up a sperm cell
Flagella(tail): propels sperm cell
Midpeice: contains mitochondria which provide energy for movement
Head: Acrosome enzyme helps the sperm move through the outer layer of the egg
What is the progression of a sperm cell
Spermagatogonia—-spermatocyte—-spermitide—imature sperm—–mature sperm
How do Male and female sterilization work
Female: Fallopian tubes are cut, tied or blocked to prevent the sperm from meeting the egg
male: vasdefrans are cut tied or blocked to prevent sperm from leaving the male body
What are sister chromatids
The name given to each component of a chromosome (the lines)
What is a haploid cell
a cell containing half the number of chromosomes(sex cells)
What are diploid cells
A cell containing 2 copies of each chromosome (somatic cells)
What is polyploidy
cells containing more than 2 sets of chromosomes
What are the stages of the cell life cycle?
INTERPHASE:
-growth phase 1: Phase of rapid growth
-synthesis phase: DNA replication of chromosomes (single-stranded to double-stranded)
-growth phase 2: preparation for cell division
DIVISION PHASE:
m phase: mitosis/ miosis takes place
cycle continues
