Chapter 2-Reproduction Flashcards
What are the five stages of the cell cycle?
G1-Increase in Cell Size, Creation of Organelles, Restriction Point 1
S-DNA replication
G2-Replication of Organelles, FURTHER cell growth, Restriction point 2
M-Mitosis/Cytokinesis
G0-Normal cell processes. DOES NOT prepare for division.
What stages of the cell cycle are also known as interphase?
G1,S,G2
What is the role of P53?
Plays a role in the two major checkpoints in the cell cycle. (G1 to S and G2 to M)
What is the role of cyclones and cycling dependent kinases?
CDK requires the binding of cyclin. Together they aid in phosphorylating transcription factors that help with with the process of transcription. Transcription of genes is necessary for the stages of cell cycle.
What stage of meiosis does crossing over occur?
Prophase I
What is synapsis?
Synapsis is the pairing of homologous chromosomes that occurs during prophase one of meiosis.
What is Mendels first law?
The law of segregation. When homologous chromosomes are separated during telophase one of meiosis.
What is Mendels second law?
The law of independent assortment. Genetic material is diversified by crossing over which occurs in prophase one of meiosis.
What is interkinesis?
Interkinesis is the period of rest between meiosis one of meiosis two.
Mitosis yields haploid or diploid cells? How many cells does a yield?
Yields two identical daughter cells.
What is cytokinesis?
The splitting of a parent cell into two daughter cells during the final stage of mitosis (telophase)
What chromosome are the sex chromosomes?
Chromosome 23
What region of the Y chromosome causes the gonads to differentiate into testes?
SRY (Sex determining region Y)
Where do sperm develop?
In the semiferous tubules of the testes
What cells nourish the testes?
Sertoli
What cells of the male reproductive system secrete testosterone and other male sex hormones?
Interstitial cells of Leydig
Where do the sperm gain mobility?
Epididymis
Where are sperm stored until ejaculation?
Epididymis
What is the pathway of sperm?
Seminal Vesicles Epididymis Vas Deferens Ejaculatory Duct N Urethra Penis
What is the function of the seminal vesicles?
Contribute fructose to nourish sperm and produces alkaline fluid.
What is the purpose of the prostate gland?
Produces alkaline fluid.
What is the purpose of the bulbourethral glands?
Produces a clear viscous fluid that cleans out any remnants of urine and lubricates the urethra during sexual arousal.
What glands produce seminal fluid?
Seminal vesicles, prostate gland, bulbourethral gland.
What are male germ cells called after the S stage?
Primary spermatocytes
What are male germ cells called after meiosis one?
Secondary spermatocytes
What are male germ cells called after meiosis two?
Spermatids
What are male germ cells called after maturation?
Spermatozoa
Describe the process of spermatogenesis.
Spermatogonium Primary spermatocytes, secondary spermatocyte, spermatid, spermatozoa.
What are the three parts of the sperm?
Head, mid piece, flagellum
Where is the genetic information stored in the sperm?
In the head. Which is surrounded by acrosome.
What part of the acrosome helps sperm fuse and penetrate the oven?
Golgi Apparatus of the head
What is the purpose of the mid piece of the sperm?
Produces ATP using fructose from the semen. Contains many mitochondria.
What is the purpose of the flagellum of the sperm?
Motility
Where is the site of ova production in females?
Ovaries
During ovulation where are eggs ovulated into?
Peritoneal sac
Where are ova drawn into?
Oviduct/Fallopian tube
Where is the site of fetal development?
The uterus
Site of sperm deposit during intercourse. Site of natural childbirth.
Vaginal canal
Completion of meiosis two results in what type of germ cell in females?
Ovum
At birth female germ cells are arrested at what phase of meiosis?
Prophase I
At puberty female germ cells are arrested at what phase of meiosis?
Metaphase II
At fertilization, female germ cells are arrested at what phase of meiosis?
Completes Meiosis II and becomes an ovum
What are the stages of oogenesis?
Oogonium > Primary Oocyte > Secondary Oocyte > Ovum
What surrounds the ovum and protects the oocyte?
Zona Pellucida
What is the corona radiata?
Layer of cells that adhere to the oocyte during ovulation.
One oogonium yields how many ovum?
1 ovum and 1 polar body
Where is gonadotropin releasing hormone GnRH produced and released from?
Produced in the Hypothalamus
Released from the pituitary gland
What is the purpose of gonadotropin releasing hormone?
Stimulates the release of FSH and LH.
What is the role of follicle-stimulating hormone in males?
It stimulates the Sertoli cells and triggers spermatogenesis.
What is the role of leutenizing hormone in males?
Causes the interstitial cells to produce testosterone
What is the role of FSH and females?
It stimulates development of the ovarian follicles. Stimulates the production of estrogen and progesterone.
What is the role of Leutinizing hormone in females?
Stimulates ovulation. Stimulates the production of estrogen and progesterone.
What are the stages of the menstrual cycle?
Follicular phase, Ovulation, luteal phase, menstruation.
What hormones are associated with the follicular phase?
GnRH stimulates FSH and LH secretion which promotes follicle maturation. Estrogen is released stimulating vascularization and glandularization of the decidua.
What hormones are associated with ovulation?
Ovulation is stimulated by a sudden surge and LH. The surge is triggered when estrogen levels reach a threshold and switch from negative to positive feedback effects.
What hormones are associated with the luteal phase?
Elevated LH causes ruptured follicles to become corpus luteum. Corpus luteum then secretes progesterone which maintains the uterine lining.
High estrogen and progesterone levels cause negative feedback on GnRH LH and FSH.
What hormones are associated with menstruation?
Estrogen and progesterone levels drop causing the endometrial lining to be sloughed off. GnRH begins to rise again.
During what phase of the menstrual cycle is estrogen positive feedback?
Ovulation
During what phase of the menstrual cycle is estrogen negative feedback?
Luteal Phase
What is the decidua?
A thick layer of modified mucous membrane which lines the uterus during pregnancy and is shed with after birth.
What hormone does the blastula produce upon fertilization?
HCG or human chorionic gonadotropin. (An analog of LH)
What does the hormone hCG do?
It maintains the corpus luteum by producing progesterone towards the beginning stages of pregnancy. Placenta takes over progesterone production later on in pregnancy.
When does menopause occur?
Between ages 45-55.
What hormones are associated with menopause?
Since menstruations stops FSH and LH levels rise.
Following ovulation, which structure releases progesterone?
Corpus luteum (remains of the ovarian follicle)
What structure produces progesterone by the end of the first semester of pregnancy?
Placenta
