Exam 5 Flashcards
What is mitosis?
Making identical daughter cells
What are the benefits of mitosis?
Good for growth and repair
How does mitosis divide?
Starts as one cell, then splits into 2, 4, 8, 16, etc
What is 2n?
Diploid, 2n means 2 times the number of chromosomes
What is meiosis?
The process where a single cell divides twice to produce 4 cells containing half the original amount of genetic information
How many rounds of cell division occurs in meisosis?
2 rounds
Are gametes haploid or diploid?
Gametes are haploid
What is 1n?
Haploid, 1n means half number of chromosomes
How many chromosomes do humans have?
46, 23 pairs
What is spermatogenesis?
The process of sperm cell development
What are the 3 parts of sperm and what are their functions?
Tail- for propulsion
Middle piece- motor, produces ATP
Head- plasma and chromosome, no golgi, no mitochondria. Just DNA
What is the role of the prostate gland?
To activate the sperm. When swollen it pinches urethra to avoid urination
Explain the hormonal regulation of testicular function.
Anterior pituitary releases LH and FSH
FSH enters blood, goes to testes, stimulates sertoli cells to produce more sperm
Inhibin is produced to lower production of sperm
LH travels to testes, stimulates interstitial cells to produce testosterone, testosterone stimulates sperm production
Negative feedback loops
Why are testes external to the body?
To be at a lower temperature to avoid cancers
Where does meiosis occur?
Testes to create sperm, ovary as oocyte development
What is it called when gametes fuse together?
Zygote
What happens in the seminiferous tubules?
Sperm production
What is acrosome?
Enzymes on the sperm that break down the surface of the egg
What does the seminal vesicle do?
Responsible for creating the semen/liquid component
What does the bulbourethral gland do?
Activates just before ejaculation and neutralizes urine
How many sperm are in one ejaculate?
200-300 million sperm
What are the other cells surrounding primary follicles in females?
Granulosa cells which produce estrogen
What happens when fertilization takes place?
HCG is released by embryo which signals CL to produce progesterone for the first trimester, then placenta takes over and produces progesterone and estrogen for rest of pregnancy
What hormone are pregnancy tests looking for?
HCG, which is excreted in urine
What are the stages of pregnancy in weeks?
Conception-2 weeks is pre embryo
Embryo- 3rd-8th week
Fetus 9th week-birth
What are outer cells of blastocyst called and what do they do?
Trophoblast cells, these become the placenta
Mass of cells inside blastocyst is called inner mass which becomes the embryo
What is viability of sperm?
48-72 hours
What is viability of oocyte?
12-24 hours
Where does fertilization have to occur to be a successful pregnancy?
In the ampulla
Why does implantation have to be successful for pregnancy to occur?
If HCG doesn’t show up, uterine wall will shed because progesterone won’t be released and fertilized thing will be lost and no pregnancy will happen
What is the one protein that’s common to all types of cancers?
P53
P53 is a checkpoint
What are the odds someone will be diagnosed with cancer?
1 in 3
What are the 4 phases of the menstrual cycle and what days do they occur?
Menstrual phase day 0-5
Proliferative phase day 6-13
Secretory phase day 14-26
Premenstrual phase day 27-28
What are the 2 phases in ovarian cycle? What causes the phase to switch?
Follicular phase switches to luteal phase on day 14/ovulation
Why does blood volume increase during pregnancy?
Increases 25-40% to accommodate extra need for nutrient delivery and gas exchange
What is a gene?
A gene is a segment of DNA thats the instructions for building a protein
Proteins give cells their function, genes dictate which proteins are present
What is a genome?
Genome is all of your DNA, every cell has the same DNA
What is gene pool?
Gene pool is the sum of all alleles in a population
What are alleles?
Variants of genes
Describe the ovarian events in order.
Begins as developing follicle, mature follicle, ovulation occurs at day 14, then corpus luteum, involution, and new follicles/corpus albicans
In females, what hormone surges just before ovulation?
LH has a large surge which triggers ovulation
What does LH do in males?
LH stimulates interstitial cells to produce more testosterone
What does FSH do in males?
FSH in male directly stimulates Sertoli cells to produce more sperm. When sufficient sperm is produced inhibin slows down sperm production
What are the germ layers and what will they become?
Ectoderm- Going to become skin and nervous system
Endoderm- Going to become lining of gut and most hollow organs- lungs, uterus, vagina
Mesoderm- Bones, muscle, heart
Describe the events of the menstrual/uterine cycle with days.
Day 1-5 beginning of menstrual flow
Day 6-14 endometrium rebuilds itself
Day 15-28 blood vessel growth built incase of pregnancy
Describe FSH role in females.
FSH - kicks everything off in development of follicles. Comes from pituitary
What is the role of granulosa cells in females?
Granulosa cells secrete low levels of estrogen to shut off FSH
What happens when estrogen levels reach their peak?
When estrogen levels reach peak, causes a surge of LH which triggers ovulation
What hormone shift occurs when fertilization doesn’t occur?
If fertilization doesn’t take place, corpus luteum secretes progesterone and estrogen
