Text Chapters 6 and 25: Cellular Reproduction Flashcards
Interphase
chromatin is diffuse, individual chromosomes cannot be distinguished
Mitosis
nuclear division retaining the original chromosome number
Meiosis
nuclear division reducing the chromosome number, leading to sperm or eggs
Cytokinesis
cytoplasmic division
Prophase
chromosomes condense, spindle forms, nucleolus disappears, nuclear envelope breaks down, each chromosome appears as a pair of chromatids attached at their centromeres
Metaphase
chromatid pairs align at the cell equator
Anaphase
sister chromatids separate and are drawn to opposite poles by spindle fibers
Telophase
chromosomes have reached poles of a cell, spindle disperses, nuclear envelope surrounds chromosomes, chromosomes becomes diffuse, nucleolus forms
Chromosome
a packaged and organized structure containing most of the DNA of a living organism
Chromatid
one copy of a duplicated chromosome, which is generally joined to the other copy by a single centromere
Centromere
the part of a chromosome that links sister chromatids
Crossing Over
homologous pairs exchange genetic information (chromosomes with combinations of maternal and paternal traits)
Spindle
a group of parallel threads stretching across the cell between its two ends (poles), where they connect to each pole at the centriole
Homologous Pair
diploids have pairs of chromosomes, each homologous pair is genetically matched so that the genes are arranged in the same order
Meiosis I
reduction division, separation of homologous chromosomes into two different nuclei, chromosome number reduced to haploid, crossing over occurs
Meiosis II
equational division, duplicated chromosomes separate, no change in chromosome number
Three Sources of Genetic Variation Related to Sexual Reproduction
alleles come from two parents, crossing over, reassortment of homologues
Cell Type at Start (Mitosis)
diploid
Cell Type at End (Mitosis)
diploid
Are Products Identical? (Mitosis)
yes
Number of Chromosome Duplications Prior to (Mitosis)
one
Pairing of Homologues (Mitosis)
no
Crossing Over (Mitosis)
no
Number of Chromosome Divisions (Mitosis)
one
Cell Type at Start (Meiosis)
diploid
Cell Type at end (Meiosis)
haploid
Are Products Identical? (Meiosis)
no
Number of Chromosome Duplications Prior to (Meiosis)
four
Pairing of Homologues (Meiosis)
yes
Crossing Over (Meiosis)
yes
Number of Chromosome Divisions (Meiosis)
two
Haploid
one set of chromosomes (n)
Diploid
two sets of chromosomes (2n)
Sister Chromatids
two identical chromatids attached at a centromere
Non-Sister Chromatids
either of the two chromatids of any of the paired homologous chromosomes (a paternal chromosome and a maternal chromosome)- exchange genetic material during meiosis
Synapsis
pairing of homologous chromosomes that occurs during prophase 1 of meiosis
Chiasma(ta)
the point where two homologous chromatids exchange genetic material during chromosomal crossover during meiosis- sister chromatids form chiasmata, non-sister chromatids for chiasma
Sperm Production
equal divisions of cytoplasm, four function products per meiosis
Egg Production
unequal divisions of cytoplasm, small polar bodies formed, one functional product per meiosis
Bulbourethral Gland
mucus secretion, movement of sperm
Epididymis
7-meter-long coiled tube, stores sperm for up to three months
Penis
has three columns of tissue that can become engorged with blood and lead to an erection
Prostate Gland
contributes alkaline fluide to neutralize acidic female reproductive tract
Scrotum
sac containing the two testes
Seminal Vesicle
makes fructose (sperm energy), prostaglandins (local hormone, stimulates muscle contraction in women)
Seminiferous Tubules
produces gametes
Testes
site of sperm production
Urethra
runs from the bladder, through the prostate, and out the shaft of the penis
Vas Deferens
place where the sperm move through during intercourse
Acrosome
contains enzymes that break down protective layers surrounding an egg
Head
contains the nucleus with the DNA
Middle Piece (body)
contains many energy-generating mitochondria
Tail
flagellum which propels the sperm
Ovary
where eggs are produced- diploid cells undergo meiosis to produce haploid eggs
Fallopian Tube
connects to the top of the uterus on both sids, ovulated oocyte moves through it
Uterus
also called the womb, where an embryo develops throughout pregnancy
Vagina
tube-like chamber into which sperm are released during intercourse
Clitoris
provides pleasure
Follicle
the small structure in which and egg will form
Corpus Luteum
a yellowish mass composed of the follicular cells remaining in the ovary which secrete progesterone and estrogen
GnRH
from hypothalamus, stimulates the pituitary to release FSH and LH
FSH
follicle stimulating hormone, influences follicle maturation, egg is developed within follicle
LH
luteinizing hormone, stimulates ovulation
Testosterone
stimulates sperm production
Estrogen
causes the regeneration of the endometrium, when estrogen levels drop, the pituitary releases FSH
Progesterone
thickens the endometrium (lining of the uterus) in preparation for a embryo
Ovulation
Triggered by a sudden ovulatory surge of LH (which ruptures the
dominant follicle), the cell (oocyte) that will become the egg is released from the ovary
into the abdominal cavity
Fertilization
the process that fuses an ovum with a sperm, eventually leading to the development of an embryo
Implantation
the very early stage of pregnancy at which the conceptus (blastocyst) adheres to the wall of the uterus