chapter 9 Flashcards
What are two differences between sexual and asexual reproduction?
sexual: between 2 organisms, and produces a lot of diversity
asexual: requires only 1 organism, and produces no diversity
What are diploid cells?
2 set of chromosomes
What are haploid cells?
1 set of chromosomes
What are autosomes and sex chromosomes?
autosomes: a non sex chromosomes
sex chromosomes: The x and Y chromosomes
What are homologous pairs ?
2 chromosomes that have the same sequence of genes
What are alleles?
Different version of genes
What are somatic cells and germ cells?
somatic: body cells (diploids)
germ: found in reproductive structures (produces Gametes)
What are gametes?
Sperm and egg (haploids)
What general events occur during prophase I?
nucleus disapears, and chromosomes condense
What general events occur during metaphase I
the pairs of chromosomes line up
What general events occur during anaphase I
homologous chromosomes seperate
What general events occur during telophase I?
new nucleus forms and chromosomes unravel
What general events occur during prophase II
when chromosomes condense and become visible
What general events occur during metaphase II?
Chromosomes line up and the cells equator
What general events occur during anaphase II?
sister chromatids begin to seperate
What general events occur during telophase II?
The nucleus reforms and chromosome unravel
What are two similarities between mitosis and meiosis II?
1) they undergo the same phases (prophase, metaphase, anaphase, teleophase)
2) they start with one cell and end with 2
What is crossing over and when does it occur during meiosis?
Its when genetic material is exchanged between homologous chromosomes and occurs during prophase 1.
What is synapsis
when homologous pairs become one
what are chiasmata?
the X thats formed to swap information
What is random alignment and when does it occur during meiosis?
how homologous pairs line up across the cells equator in metaphase 1
How is the expression, 2n, used to determine the amount of variation produced by random alignment?
to calculate the potential number of different genetic combinations produced by random alignment
What are four differences between mitotic division and meiotic division?
1) mitosis only has 1 division, meiosis has 2
2) mitosis creates 2 daughter cells, meiosis creates 4
3) mitosis has identical daughter cells, meiosis doesnt
4) mitosis doesnt have crossing over/ independent assortment, meiosis does
What is nondisjunction?
an improper seperation of chromosomes
What are polyploid cells and aneuploid cells?
polypoid: cell with extra chromosome sets
aneuploid: cells with 1 more or 1 less chromosome set
What are chromosomal deletion
some genes on the chromosomes are eliminated
What are chromosomal duplication?
some genes on the chromosomes are duplicated and added
