Question

3. What is crossing over? When does it occur during meiosis? Why did you have difficulty modeling this element of meiosis using your “chromosomes?”

Answer 1

Crossing-over is when tetrads cross over. Parts of the genes mix with each other, and separate again to form two completely different chromosomes. This is what allows for genetic diversity.

Answer 2

1. Crossing over is when two chromosomes exchange their genetic materials in a process called synapsis.
2. It occurs in meiosis 1 during prophase 1.
3. One example: Your chromosomes may end up crossing over with wrong chromosomes due to mutation in one of the chromosome or both.

Answer 3

Thank you so much!!

Answer 4

@bpaulorg could you help me with a couple more?
4. Think about your modeling. Visually, what is the major difference between the separation of chromosomes between anaphase I and anaphase II
5. What is independent assortment? When does it occur during meiosis? How did you model this element of meiosis?

Answer 5

4. Major difference will be your number of chromosomes. Let say, in anaphase 1 you can have 4 chromosomes pairs while in anaphase II, this will be reduce to only 2 chromosomes pairs.
5. Independent assortment is Mendel's 2nd law which stated that gene pairs will separate independently during gamete formation. It occurs in meiosis 1 during anaphase 1 while genetic informations are being exchange. You can click on the website link below to see the animation itself.
http://www.sumanasinc.com/webcontent/animations/content/independentassortment.html