How do two alleles of the CFTR gene in a lung cell differ?
How do the two alleles of the CFTR gene in a lung cell differ? They are inherited from different parents. … The genotype includes two mutant CFTR genes, one each on the homologous chromosomes for chromosome 7. A diploid cell of baker’s yeast has 32 chromosomes.
Which processes lead to genetic variation?
Genetic variation can be caused by mutation (which can create entirely new alleles in a population), random mating, random fertilization, and recombination between homologous chromosomes during meiosis (which reshuffles alleles within an organism’s offspring).
How does crossing over increase variation in a population?
How does crossing over increase variation in a population? It produces offspring with [combinations of alleles] that neither parent carried. … Sometimes mistakes happen, and crossing over occurs between nonhomologous regions of homologous chromosomes, resulting in duplications and deletions.
Is the DNA replicated after meiosis I Why or why not?
No, because DNA is replicated in Interphase first and no interphase stage exists after after Meiosis 1. Describe the main difference between Metaphase 1 and Metaphase 2. In Metaphase 1, paired homologous chromosomes line up along the equator of the cell. … It is a regular mitosis when chromosomes are not duplicated.
How is genetic diversity created in meiosis?
During prophase of meiosis I, the double-chromatid homologous pairs of chromosomes cross over with each other and often exchange chromosome segments. This recombination creates genetic diversity by allowing genes from each parent to intermix, resulting in chromosomes with a different genetic complement.
What is crossing over and recombination?
During meiosis I homologous chromosomes often exchange chromosome tips in a process called recombination (crossing over). Crossing over re-arranges the combination of alleles within a chromosome, thus adding to the potential genetic variation found between individuals. …
What are the 5 sources of genetic variation?
Genetic variation is caused by:
- random mating between organisms.
- random fertilization.
- crossing over (or recombination) between chromatids of homologous chromosomes during meiosis.
What are the 3 types of genetic variation?
There are three sources of genetic variation: mutation, gene flow, and sexual reproduction.
What are the three ways meiosis increases genetic variation?
We have seen that meiosis creates variation three ways: crossing over, mutations caused during crossing over, and independent assortment.
Does crossing over increase genetic variation?
Crossing over is a process that happens between homologous chromosomes in order to increase genetic diversity. During crossing over, part of one chromosome is exchanged with another. … Gametes gain the ability to be genetically different from their neighboring gametes after crossing over occurs.
Which separates sister chromatids during meiosis?
Meiosis II separates sister chromatids.
Why are there two stages in meiosis?
These goals are accomplished in meiosis using a two-step division process. … Since cell division occurs twice during meiosis, one starting cell can produce four gametes (eggs or sperm). In each round of division, cells go through four stages: prophase, metaphase, anaphase, and telophase.
What is the main difference between meiosis 1 and 2?
Answer and Explanation:
The difference between meiosis 1 and meiosis 2 is that in meiosis 1 homologous chromosomes separate. Whereas in meiosis 2 sister chromatids separate. Meiosis 1 produces diploid daughter cells, while meiosis 2 produces haploid daughter cells. Additionally, crossing over occurs only in meiosis 1.
What is the difference between DNA replication and mitosis?
The difference between DNA Replication and cell division is that DNA Replication is passing down genetic material, while Cell Division is when a parent cell divides to form two daughter cells.