Meiosis, Karyotyping, Non-Disjunction Flashcards
A human somatic cell has ______ (how many autosomes and sex chromosomes?)
22 pairs of autosomes
1 pair of sex chromosomes
What is the most common chromosome in the human body?
autosomes
On what type of chromosomes are the same sequence of genes found?
homologous chromosomes
Human somatic cells are ________, gametes are ______.
somatic cells are diploid
gametes are haploid
True/False:
the cells entering mitosis have the same amount of DNA as cells entering meiosis
true
When do the chromosomes in gametes replicate?
before meiosis I
Before crossing over, sister chromosomes are _______.
identical
Name a difference between meiosis and mitosis.
- varying answers
ex. single cell is divided into two cells in mitosis and four cells in meiosis.
The two daughter cells produced by meiosis I do undergo __________ before meiosis II.
cytokinesis
In which processes are sister chromatids separated?
both mitosis and meiosis
Define independent assortment.
random segregation of one member of each homologous pair of chromosomes into gametes
What is the site where crossing over takes place called?
chiasma
The nondisjunction of sex chromosomes causes ________.
chromosomal abnormalities
An organisms haploid number is ________.
1/2 of its diploid number
What type of cell has one allele for each gene?
gamete
During which phase do chromosomes form tetrads?
Prophase I of meiosis
Define tetrad.
two homologous chromosomes
What kind of cells does meiosis result in?
four genetically different cells
True/False:
genes on the same chromosome assort independently
true
Somatic cells contain _____ the number of chromosomes found in gametes.
twice
If an organism contains genetic information from two parents, what is it said to be?
diploid
What are homologous chromosomes?
two genetically similar chromosomes, one from each parent
True/False:
sister chromatids transfer DNA between each other
false
Which phase in meiosis does not contribute to genetic diversity?
metaphase of meiosis II
