Meiosis Chapter 19 Flashcards
Of your 46 chromosomes, 23 come from your mom and 23 come from your dad. The chromosomes from mom and the chromosomes from dad pair up in the nucleus of your cell. These pairs carry genes for the same traits. These pairs are called ________ ________
homologous chromosomes
When homologous chromosomes lines up side by side its called __________.
synapsis
The presence of a chromosome segment to another non-homologous chromosome is called ________ _______.
crossing over
A __________ occurs when an end of a chromosome breaks off
translocation
An _______ is when a segment of a chromosome is turned around 180 degrees
inversion
males taller than average, persistent acne, speech and reading problems, fertile, XYY
Jacob’s Syndrome
females are short, folds of skin on back and neck, do not undergo puberty, normal behavior, X
Turner Syndrome
females have no distinctive phenotype, may have delayed language/motor development, extra Barr bodies, XXX or XXXX
Poly-X
Males are infertile without medical help, speech/language delays, XXY or XXXY
Klinefelter Syndrome
Meiosis is necessary for _________ reproduction
sexual
Meiosis creates ____ daughter cells
4
Daughter cells have _ of each type of chromosome or _____ as many as the parent cell
1
half
This process reduces the number of chromosomes in daughter cells
reduction division
The process makes sure that each of the resulting daughter cells is not a genetic replicate of the parent cell, but have a new combination of genetic material
genetic division
Homologous chromosomes pair during synapsis allowing for crossing over to occur and introduces genetic diversity
prophase I
Independent assortment occurs when homologous chromosomes pair along the _________ plate in _______ __
metaphase
metaphase I
Homologous chromosomes sepreate, pull to opposite pole by centromeric spindle fibers
Anaphase I
Daughter cells have 1 chromosome from each homologous pair
Telophase I
Chromosomes still consist of 2 chromatids
cytokinesisWh
What does meiosis II result in?
4 haploid (single set of unpaired chromosomes) daughter cells
Cells have 1 chromosome from each homologous pair
prophase II
Chromosomes align at metaphase plate
Metaphase II
Daughter chromosomes move toward poles
Anaphase II
Spindle disappears, nuclei form, and cytokinesis takes place
Telophase II
Cytoplasmic division of cell that makes them seperate into 2 daughter cells
Cytokinesis
The exchange of genetic information between homologous chromosomes
crossing over
Homologous pairs align independently at the equator, there is no specific order in which they line up
independent assortment
Too few or too many ________ can create sever abnormalities
What checkpoint should catch this?
chromosomes
spindle checkpoint
When chromatids fail to separate from each other
nondisjunction
The absence of a chromosome
monosomy
Inheritance of an extra chromosome
Autosomal ___ are lethal with the exception of ___ 21
Trisomy
Extra protein causes developmental and intellectual disabilities in down syndrome or _____ ___
Trisomy 21
