Meiosis Mechanics
What type of cells are produced through meiosis?
What are gametes? (Sperm and Egg Cells)
What is crossing over?
Exchange of DNA between homologous chromosomes.
What is a mutation?
A change in DNA sequence
Which process produces genetically identical daughter cells?
Mitosis
If a cell has 46 chromosomes, how many will each gamete have after meiosis?
23
How many daughter cells are produced at the end of meiosis?
What are 4 daughter cells.
What is independent assortment?
Random alignment of homologous chromosomes leading to different gamete combinations during meiosis.
Which mutation changes only one amino acid?
Missense Mutation
Which process produces haploid cells?
Meiosis
True or False: Crossing over happens in metaphase I of meiosis.
False, it occurs in prophase I.
Are cells produced by meiosis haploid or diploid?
What are haploid.
During which phase does crossing over occur?
Prophase I
Which mutation creates a premature stop codon?
Nonsense Mutation
True or False: Interphase occurs in both meiosis & mitosis.
True, BUT in meiosis, it only occurs before meiosis I, not before meiosis II.
A mutation occurs in a skin cell. Will it be passed to offspring? Why or why not?
No, because it is not in a gamete.
During which phase do homologous chromosomes separate?
What is Anaphase I.
How do crossing over AND independent assortment increase variation?
Crossing over swaps DNA between chromosomes; independent assortment creates different combinations of chromosomes in gametes
What is a chromosomal mutation and how is it different than a gene-level mutation?
Chromosomal mutations are mutations that affect entire segments of the chromosome (many genes) while gene-level mutations only affect one gene and therefore, one protein.
This process occurs in somatic cells.
Mitosis
Explain how genetic variation helps populations adapt to climate change.
Some individuals may have traits that improve survival in new conditions. More traits= more options for survival.
Explain how meiosis I and meiosis II are different.
Meiosis I separates homologous chromosomes (and crossing over, independent assortment happens) and Meiosis II separates sister chromatids (much like mitosis).
BEST ANSWER WINS! Explain how TWO different processes during meiosis create genetic variation. Then explain why this variation matters for a population.
Crossing over + independent assortment create new allele combinations. This variation increases differences among individuals, helping populations survive environmental changes and increasing chances of adaptation.
BEST ANSWER WINS: List as many examples of chromosomal mutations as you can and briefly describe each.
Nondisjunction- Homologous chromosomes or sister chromatids fail to separate in anaphase I or II so gametes are either +1 or -1 chromosomes.
Deletion- Entire segments of chromosome are missing
Insertion- Entire segments of chromosome are duplicated.
Inversion- A pieces of the chromosome is flipped around.
Translocation- A piece of one nonhomologous chromosome breaks off and attaches to another.
Why would it be problematic if gametes were produced by mitosis instead of meiosis?
Chromosome number would double each generation, leading to genetic instability.
Which creates MORE genetic variation?
A) Crossing Over
B) Independent Assortment
C) Mutation
Mutation creates new alleles (ultimate source), but meiosis processes create new combinations — Because meiosis cannot shuffle new alleles if there are none, mutation is most impactful long-term