Chapter 2.2 Flashcards
1
Q
What is the purpose of Meiosis 1 and Meiosis 2
A
Meiosis 1
- > results in homologous chromosomes being seperated
- > generates haploid daughter cells
- > this is referred to as reductional division
Meiosis 2
- > separation of sister chromatids
- > known as equational division
2
Q
What is the difference between sister chromatids and homologous chromosomes
A
- sister chromatids
- > identical strands of DNA
- > connected at the centromere
- homologous chromosomes
- > considered separate chromosomes
3
Q
What are the major components of prophase 1
A
- homologous chromosomes come together
- > they intertwine in a process called synapsis
- chromatids of homologous chromosomes may break at the point of contact(chiasma)
- > exchange equivalent pieces of DNA
- > this exchange of DNA is referred to as crossing over
4
Q
Do sister chromatids cross over or do homologous chromosomes cross over? What is the advantage of crossing over?
A
- only homologous chromosomes cross over
- > sister chromatids do not cross over
- the advantage of crossing over is that it can unlink linked genes
- > increases the variability within the genetics of the offspring
5
Q
How does gene linkage determine whether a gene is inherited with another gene?
A
- linkage refers to the tendency for genes to be inherited together
- > genes that are located farther from each other are less likely to be inherited together
- > more likely to undergo crossing over relative to one another
6
Q
What Mendel law does crossing over relate to?
A
- Mendel’s second law
- > law of independent assortment
- > it states the inheritance of one allele does not have an effect on the likelihood of inheriting certain alleles for other genes
7
Q
What occurs during metaphase 1? What part is different from that of metaphase during prophase
A
- homologous pairs(tetrads) line up at the metaphase plate
- unlike mitosis
- > there is only spindle fiber going through the chromosomes
- in mitosis
- > there are two spindle fibers going through the chromosomes
8
Q
What Mendel’s law does anaphase 1 relate to?
A
- it accounts for Mendel’s fist law
- > the law of segregation
- during anaphase 1
- > each chromosome of paternal origin seperates from its homologue of maternal origin
-the separation of homologous chromosomes is referred to as segregation
9
Q
What happens in anaphase 2?
A
- centromeres divide
- >separating the chromosomes into sister chromatids
