M8: Meiosis Flashcards
Meiosis in males is called ________________ and produces sperms.
spermatogenesis
Meiosis in females is called __________ and produces ova.
oogenesis
Two MAJOR stages in meiosis (meiosis __ and meiosis ___).
meiosis I and meiosis II
fertilization
23 egg cell + 23 sperm cell = 46 _________
zygote
cell division that produces gametes
meiosis
differences of mitosis and meiosis
mitosis
- ___ cell division
- __ daughter cells
- _______ = 2n
- __ chromosomes
meiosis
- __ cell division
- __ cell product
- _________ = n
- ___ chromosomes
differences of mitosis and meiosis
mitosis
- 1 cell division
- 2 daughter cells
- diploid = 2n
- 46 chromosomes
meiosis
- 2 cell division
- 4 cell product
- haploid = n
- 23 chromosomes
top of the chromatid - ____ color
bottom of chromatid - ____ color
top of the chromatid - eye color
bottom of chromatid - hair color
location where you can find gene
locus
Phases of Cell Division of Gametes
Same in mitotic division (G1. S- phase, G2)
Replication of DNA
Homologous chromosomes
interphasw
Same gene sequence
Same loci
Centromere location
Chromosomal length
Homologous chromosomes
Prophase I
Divided into 5 stages;
l________
Z__________
P___________
D_________
d_____________
Divided into 5 stages;
Leptotene
Zygotene
Pachytene
Diplotene
Diakinesis
chromosomes begin to condense and attain a compact structure.
leptotene
Chromosomal synapsis - pairing of chromosomes.
zygotene
connects and pairs the two homologous chromosomes
Synaptonemal complex
Forms a bivalent/ tetrad.
Homologous pairs
zygotene
a continuation of what happens in gap 2
leptotene
Synaptonemal complex
zygotene
crossing over of non-sister chromatids of homologous chromosomes.
pachytene
Cross - linked of one arm of non - sister chromatids at the Recombination nodule
pachytene
Formation of chiasmapachytene
pachytene
crossing over of genes - exchange of gene
pachytene
one of the most important processes wherein variation of cells happen
pachytene
a break in one of the sister chromatids
chiasma
marks the dissolution of the synaptonemal complex
diplotene
separation of the homologous chromosomes of the bivalents except at the sites of cross-over.
diplotene
diplotene
The X-shaped structures formed during separation are known as ___________
chiasmata
Termination of chiasmata
diakinesis
assembly of the meiotic spindle to separate the homologous chromosomes.
diakinesis
nucleolus disappears and the nuclear envelope breaks down.
diakinesis
Longest and most complex phase (90%).
prophase 1
Chromosomes condense.
prophase 1
Synapsis occurs: homologous chromosomes come together to form a tetrad.
prophase 1
prophase 1
______- is two chromosomes or four chromatids (sister and nonsister chromatids).
tetrad
Shortest phase
Metaphase I
Alignment of chromosomes at the center.
Metaphase I
Independent Assortment: Variation
Metaphase I
Random pairing of chromosomes in the middle
Formula: 2^n
8,____,608 combinations (humans)
8,388,608 combinations
s a tool used by scientists to identify, organize, and study human chromosomes
Karyotyping
CHROMOSOMAL DISORDERS
PROBLEM DURING __- PHASE (REPLICATION) > Structure of c____________ > Deletion, d__________, Inversion, t_________
PROBLEM DURING S- PHASE (REPLICATION) > Structure of chromosomes > Deletion, duplication, Inversion, translocation
CHROMOSOMAL DISORDERS
PROBLEM DURING METAPHASE, METAPHASE 1 OR 2 >
Number of chromosomes
> non_____________> eu____
and an______
CHROMOSOMAL DISORDERS
PROBLEM DURING METAPHASE, METAPHASE 1 OR 2 >
Number of chromosomes
> nondisjunction > Euploidy
and Aneuploidy
removes a chromosomal segment
deletion
AKA 5p- syndrome or cat cry syndrome
Cri du chat syndrome
is a rare genetic condition that is caused by the deletion of genetic material on the small arm (the p arm) of chromosome 5.
Cri du chat syndrome
high-pitched cat-like cry
Cri du chat syndrome - Symptoms
mental retardation
Cri du chat syndrome - Symptoms
delayed development
Cri du chat syndrome - Symptoms
distinctive facial features, small head size (microcephaly)
Cri du chat syndrome - Symptoms
widely-spaced eyes (hypertelorism)
Cri du chat syndrome - Symptoms
low birth weight
Cri du chat syndrome - Symptoms
weak muscle tone (hypotonia) in infancy.
Cri du chat syndrome - Symptoms
repeats a segment
duplication
duplication of chromosomal material on the long arm (q) of one of the chromosomes
Partial Trisomy 13q Syndrome
abnormal facial features
Partial Trisomy 13q Syndrome
growth and developmental delays, and birth abnormalities.
Partial Trisomy 13q Syndrome
also a mental health retardation
Partial Trisomy 13q Syndrome
X -Chromosome defect
Do not produce factor VIII
Excessive bleeding
Hemophilia A
reverses a segments within a chromosome
inversion
moves a segment from one chromosome to another non homologous one
translocation
Infertility and Cancer
translocation
occurs when homologous chromosomes (meiosis I) or sister chromatids (meiosis II) fail to separate during meiosis.
Nondisjunction
refers to the state of having a chromosome number that is an exact multiple of a chromosome number.
Euploidy
Euploidy
haploid > diploid (2) > T_______ (3) > t_________ (4)
Euploidy
haploid > diploid (2) > triploid (3) > tetraploid (4)
refers to the state of having a chromosome number that is an exact multiple of a chromosome number common in plants.
Euploidy
Common in plants, rarely in animals.
Causes formation of new species
Euploidy
Refers to a condition in which one or a few chromosomes are added or deleted from the normal chromosome number.
Aneuploidy
Aneuploidy
- N__________
- Monosomy
- t___________
- tetrasomy
- Nullisomy
- Monosomy
- Trisomy
- tetrasomy
Very lethal in humans
Nullisomy Disorder
Turner’s Syndrome
results from
Monosomy
signs of what syndrome from monosomy
short stature
low hairline
shield shaped thorax
widely spread nipples
shortened metacarpal IV
small fingernails
brown spots (nevi)
Turner’s Syndrome
signs of what syndrome from monosomy
characteristic facial features
fold of skin
constriction of aorta
poor breast development
elbow deformity
redimentary ovaries gonadal streak (underdeveloped gonadal structures)
no menstruation
Turner’s Syndrome
syndromes because of trisomy
Trisomy 21 Syndrome
Down’s Syndrome
what syndrome from trisomy has this signs and symptoms
growth failure, mental retardation
flat back of head
abnormal ears
many “loops” on fingertips
palm crease
special skin ridge patterns
unilateral or bilateral absence of one rib
intestinal blockage
umbilical hernia
abnormal pelvis
diminished muscle tone
Down’s Syndrome
what syndrome from trisomy has this signs and symptoms
broad flat face slanting eyes epicanthic eyefold
short nose
short and broad hands
small and arched palate
big wrinkled tongue
dental anomalies
congenital heart disease
enlarged colon
big toes widely spaced
Down’s Syndrome
syndrome because of tetrasomy
48,XXXX syndrome
what syndrome from tetrasomy has this signs and symptoms
Mild to moderate speech and learning difficulties;
developmental delay;
distinctive facial features;
dental abnormalities;
hypotonia and joint laxity;
48,XXXX syndrome
what syndrome from tetrasomy has this signs and symptoms
radioulnar synostosis;
heart defects;
hip dysplasia;
problems with ovarian function.
48,XXXX syndrome
