During meiosis, the cells divide two successive times to produce gametes with half the chromosomes found in the parent cell. To a large extent, this process includes the construction of the chromosomes prior to their division into other cells. There are now homologous pairs, one member of which is a gene of each parent, which are free to move around independently of the manner in which other pairs are arranged. The arrangement is quite crucial to sexually reproducing animals since it assists in maintaining the variety of their genes.
Let’s explore the full answer to the question:
“Homologous pairs of chromosomes are lined up independently of other such pairs during _____.”
A) Prophase I
B) Metaphase I
C) Anaphase II
D) Telophase I
Correct Answer: B) Metaphase I
Explanation
During meiosis I, similar pairs of chromosomes are grouped together in a line-up-away fashion with respect to other similar pairs at the Metaphase I. Inferred chromosomes at this stage, line up pairwise in the equatorial plane of the cell. The orientation of each pair is not based on the others and varies from each other. One important way that gametes have different types of genes is through “independent assortment.”
Examples include
- Under the formation of human gametes, at Metaphase I, there are 23 pairs of chromosomes that can align in excess of 8 million arrangements.
- The independent assortment made the features of Gregor Mendel in pea plants different.
What is Independent Assortment?
During Metaphase I, the chromosome pairs are not in any particular order. In other words, the maternal and male chromosomes are spread out into gametes without changing the order of the other chromosomes.
Key features:
- This only happens during meiosis and not mitosis.
- Makes children have more genetic diversity.
- Works alongside crossing over to create unique genetic combinations.
Key Elements
- Stage: This is the first stage of meiosis.
- Process: At the metaphase plate, identical pairs are lined up randomly.
- Outcome: Different mixes of genes in gametes.
- Significance: Important for differences in species that reproduce sexually.
FAQs
Q1: Does independent assortment occur in mitosis?
No, it’s only a part of meiosis I.
Q2: How does independent assortment differ from crossing over?
Crossing over is when genetically identical chromosomes share DNA, and independent sorting is when whole chromosomes are spread out at random.
Q3: Why is Metaphase I important for evolution?
It creates genetic variation, which is required to enable living things to adapt and survive.
Q4: How many possible chromosome combinations can humans produce through independent assortment?
Without counting cross-over versions, there are over 8 million different ways to arrange these cards.
