CH2 Reproduction Flashcards
Oogenesis Steps
Unequal Cytokinesis?
What triggers Meiosis 2?
Germ cells are Oogonia are the supply given before birth
- Oogonia become a primary oocyte
- Primary Oocyte undergoes Meiosis 1 and forms 1 Secondary Oocyte and 1 polar body (cell with little cytoplasm and organelles)
- Sperm fertilizes Secondary Oocyte in the fallopian tube and Meiosis 2 occurs. and forms 1 Ovum and 1 polar body
- After the sperm nucleus fuses it becomes a Zygote
Sperm Pathway.
interstitial cells of Leydig role?
SEVE(N) UP
Seminiferous tubules
Epididymis
Vas deferences (or ductus deferens)
Ejaculatory duct
(Nothing)
Urethra
Penis
interstitial cells of Leydig: secrete testosterone and other male sex hormones (androgens)
Spermatogenesis Steps
Role of Sertoli cells? Interstitial Cells of Leydig? what promotes them
- Spermatogonium (undergoes mitosis) and one goes back as Spermatogonium
=
- Primary Spermatocyte (undergoes meiosis 1)
=
- two Secondary Spermatocyte (undergo meiosis 2)
=
- four non-identical immature spermatids (undergo changes)
- four spermatozoids
- FHS stimulates Sertoli cells and triggers sperm maturation
- LH causes interstitial cells of Leydig to produce testosterone (exerts negative feedback to the hypothalamus and Anterior P to maintain an appropriate range)
Interphase, MITOSIS: Prophase, Metaphase, Anaphase, Telophase and Cytokinesis
Interphase: Chromosomes (DNA) replicates making a pair and all that its called chromatin and centrosome replicates
1 cell with 46 chromosomes to split into 2 each with 46 chromosomes
Prophase: Chromosomes condense (chromatin into chromosome), microtubules (kinetochore fibers) begin to from. Nucleus still there
Metaphase: Microtubules are attached to the centromeres in the Chromosomes and line-up along the equatorial plate
Anaphase: sister chromatids are separated and pulled to opposite poles
Telophase: Nuclear membrane reforms, spindle disappears and the cell is cleaved by cytokinesis
XX and XY
what chromosome?
Role of Y and X chromosome
X only carried by eggs.
Sperm can carry either X or Y
after sex;
XX = Female
XY = Male
Y chromosom= little genetic info (is the one that determines testis differentiation.
X= a lot of info. therefore, males are more prone to exhibit a disease caused in the X chromosome (sex-linked disease comes from the X). While females can have 2 X but don’t show, therefore, they are carries
S Stage and G2 Stage
Synthesis of DNA: DNA is replicated. Each cell has chromosomes consisting of 2 identical chromatids bound together at eh centromere.
G2 Postsynthetic Gap: Makes sure there are enough organelles and cytoplasm. And if DNA was replicated correctly
(right before mitosis)
G0 and G1
G0: The cell is just living doing its functions
G1 (Presynthetic Gap): Cell creates organelles for energy and protein production (mitochondria, ER, Ribosomes) an increase in size. There is one restriction point to pass to S phase
Control of the Cell Cycle G1/S and G2/M and CDKs
G1/S: Makes sure DNA is good for synthesis. If not protein p53 will arrest the cycle until DNA is repaired
G2/M: Makes sure that organelles are replicated and the size is good. p53 also plays a role
Cyclin-dependent Kinase: With the presence of cyclins they can phosphorylate transcription factors and promote the different stages
Meiosis
Produces 4 nonidentical haploid (half of a full set of chromosomes) sex cells (gametes)
has one round of replication and 2 of division
Prophase 1: mother and dad chromosome (46) line on top of each other (form 4 chromatids) called crossover and they exchange DNA sections called recombination
Metaphase 1: Microtubules are attached to the centromeres in the Chromosomes and line-up on opposite sides of the equatorial plate. (not like mitosis (directly on the line))
Anaphase 1: chromosomes are separated and pulled to opposite poles (each pole with 23 chromosomes) haploid
Telophase 1: Nuclear membrane reforms, spindle disappears and the cell is cleaved by cytokinesis
Miosis 2: similar to mitosis
Prophase 2: no DNA replication
Metaphase 2: =
Anaphase 2: sister chromatids are pulled apart
Telophase 2: new nuclear membrane forms
The Menstrual Cycle/ pregnancy
Follicular Phase?
Luteal Phase?
Ovulation?
Menopause
Follicular Phase
- Follicle made of granulosa cells grows because FSH and LH (released from APG) levels rise. Granulosa cells secrete estrogen, inhibin, and progesterone. Secretes more estrogen because it’s getting bigger
Ovulation
- Follicle ruptures releasing the egg (day 14)
Luteal Phase
- Estrogen level drops = FSH drops, and ruptured follicle becomes Corpus Luteum = progesterone increases
- high levels of progesterone cause negative feedback and avoids GnRH, LH and FSH to keep secreting
if no egg is fertilized CL dies
Menopause: ovaries become less sensitive to FHS and LH
Female Puberty
FSH role, puberty, and adulthood
LH, corpus luteum?
what happens after 1st trimester?
FSH: promotes estrogen secretion which in puberty produce breast growth, widening of the hips, and changes in fat distribution
in adulthood to the thickening of the uterus each month
LH: promotes progesterone secretion from the corpus luteum, which helps maintain the endometrium (uterus for implantation)
after 1st-trimester corpus luteum dies and progesterone is supplied from the placenta
nondisjunction division
How do mitochondria get transport in a neuro cell
Sperm parts? Head, middle, tail?
Head: covered by acrosome (made in the Golgi apparatus and needed to penetrate the ovum) has little to no Cytoplasm
Middle: Has mitochondria that can form ATP from fructose
Tail: contains the flagella to move (made of microtubules)
Seminal Fluid? composed by what
Seminal Vesicles
Prostate gland
Bulbourethral (Cowper’s) glands
Seminal fluid made in:
- Seminal Vesicles = provide fructose to sperm
- Prostate gland = contributes to the alkaline environment
- Bulbourethral (Cowper’s) glands = provide precum to clean and lubricate the urethra
