Biology: Chapter 2: Reproduction Flashcards
Diploid vs Haploid
Diploid (2n) –> two copies of each chromosome
Haploid (n) –> one copy of each chromosome
What are the stages of the cell cycle
G1, S, G2 (Interphase) and M
what is the G1 phase
cells create organelles for energy and protein production + increase their size (normal cell function)
what is the restriction point
between G1 and S where DNA is checked for quality
what is S phase
DNA replication
what is G2 phase
further cell growth, organelles are copied, cell prepping for mitosis
what are the phases of mitosis
prophase, metaphase, anaphase, telophase
what is cytokinesis
after telophase; division of the cytoplasm
what is p53
protein that plays major roles in checkpoints between G1/S and G2/M
How are cyclins and CDK related to the cell cycle
Cyclins bind to CDKs which then phosphorylates/activates transcription factors
what is cancer
uninhibited division of damaged cells without regard to quality or quantity
Cell cycle of somatic vs gametes
somatic –> mitosis
gametes –> meiosis
What is prophase
chromosomes condense, the nuclear envelope dissolves, centrioles migrate to opposite sides and the spindle apparatus forms; kinetochore of each chromosome is contacted by a spindle fiber
what is metaphase
chromosomes line up along metaphase plate
what is anaphase
sister chromatids are pulled to opposite sites of cell
what is telophase
nuclear membrane reforms, spindle apparatus. disappears
what are the stages of meiosis
meiosis I –> prophase I, metaphase I, anaphase I, telophase I
Meiosis II –>. prophase II, metaphase II, anaphase II, telophase II
what are the two rounds of division in meiosis
reductional division and equational divison
what is prophase I
same as prophase except homologues come together and intertwine during synapsis; crossing over exchanges genetic material (Mendels second law)
what are homologues
chromosomes given same number but opposite parental origins (NOT IDENTICAL); form a tetrad
what is metaphase I
homologous chromosomes line up on opposite sites of metaphase plate
what is anaphase I
homologous chromosomes are pulled to opposite poles (Mendels first law of segregation)
what is telophase I
chromosomes may or may not decondense; and cell may enter interkinesis after cytokinesis
what is meiosis II
functionally similar to stages of mitosis
what is hemizygous
males are XY meaning they will express sex linked diseases more frequently
what is important about the Y chromosome
carries the SRY (sex determining region Y) which causes the release of androgen so the gonads develop into testes
where does sperm develop
in the seminiferous tubules in the testes
what are sertoli cells
located in the seminiferous tubules that nourish sperm cells
what are the interstitial cells of leydig
located in the testes; secrete testosterone and other sex hormones
where are the testes located
scrotum
what is the epididymis
located on top of testes; store sperm until ejaculation; where sperm gain motility
what is the path of ejaculation (SEVE(N) UP)
S –> Seminiferous tubules
E –> Epididymis
V –> Vas Deferens
E –> Ejaculatory duct
U –> Urethra
P –> Penis
what are the seminal vesicles
contribute fructose to nourish sperm and produce alkaline fluid
What is the function of the prostate gland
produces alkaline fluid
what is the bulbourethral glands
produce pre-ejaculation that cleans out remnants of urine and lubricates the urethra during sexual arousal
what is the stages of development of a mature sperm cell (spermatogenesis)
spermatogonium –> Primary spermatocyte –> secondary spermatocyte –> spermatid –> spermatozoa
what is the structure of a sperm cell
head –> acrosome (modified golgi with enzymes to penetrate the ovum)
midpiece –> generates ATP from fructose and contains many mitochondira
Flagellum
where are OVA produced
follicles and ovaries
what is oogenesis
one haploid ovum and variable number of polar bodies are formed from oogonium
what is a primary oocyte
undergone replication and arrested in prophase I
what is a secondary oocyte
ovulated egg which is arrested in metaphase II
what happens when oocyte is fertilized
completed meiosis II and becomes and ovum
what is the structure of an oocyte
oocytes are surrounded by zona pellucida and the corona radiata
what is gonadotropin releasing hormone
released from the hypothalamus and causes the release of follicle stimulating hormone and luteinizing hormone
what does FSH and LH do in males
stimulates the sertoli cells and triggers spermatogenesis while LH causes interstitial cells to release testosterone
what does FSH and LH do in females
FSH stimulates development of ovarian follicles while LH causes ovulation; also stimulates production of estrogen and progesterone
what is the follicular phase of the menstrual cycle
GnRH secretion causes FSH and LH secretion which promotes follicle development; Estrogen is released stimulation vasculatization and glandularization of the decidua
what is ovulation
stimulated by surge of LH which is triggered by estrogen levels reaching a threshold in the follicular phase causing a positive feedback loop
what is the luteal phase
LH causes the ruptured follicle to become the corpus luteum which secrete progesterone that maintains the uterine lining; High estrogen and progesterone levels cause negative feedback on GnRH, LH, and FSH
what is menstration
occurs with no fertilization; estrogen and progesterone levels drop and block on GnRH production is removed
what happens during menstrual cycle if fertilization happens
the blastula produces human chorionic gonadtropin (hCG) which maintains corpus luteum; near end of first trimester hCG levels drop as the placenta takes over progesterone production
what happens during menopause
ovaries stop producing estrogen and progesterone; menstruation stops and FSH and LH levels rise
