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Crossing over and random alignment of chromosomes
Wiki User
∙ 11y ago
Wiki User
∙ 12y agootherwise we would all be thE same
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What is meant by 'scrambling of allelic combinations?
Recombination, or crossing over, is the exchanging of DNA between homologous chromosomes at meiosis. It results in novel combinations of alleles in the gametes, that is, it scrambles the alleles into new combinations, Let's take an example of an individual that has genes A,B and C on one chromsome, and has the alleles a and c on the other chromosome of the pair: A---B---C a---B---c If crossing over occurs between the genes A and B (and not between B and C), then we can get the following genotypes in the gametes, in addition to the above two combinations: : A---B---c a---B---C Crossing over has scrambled the allelic combinations and given us two new additional ones in the gametes. If we allow recombination between B and C, then even more combinations are possible. One can easily see how recombination can add enormous amounts of genetic variation into a population. Also, note that if no recombination occurs, only the two original combinations of alleles will make it into the gametes.
Is it true or false that during meiosis the two alleles for each gene stay together?
False. During meiosis, the two alleles for each gene can separate and be distributed to different gametes. This is known as Mendel's law of independent assortment, which allows for new combinations of alleles to be formed in offspring.
Does sexual reproduction create new alleles or new combinations of alleles?
new combinations of alleles
When alleles on homologous chromosomes move into different gametes during meiosis this demonstrates?
Segregation
What creates different combinations of maternal and paternal chromosomes in gametes?
Independent assortment
What is meant by 'scrambling of allelic combinations?
Recombination, or crossing over, is the exchanging of DNA between homologous chromosomes at meiosis. It results in novel combinations of alleles in the gametes, that is, it scrambles the alleles into new combinations, Let's take an example of an individual that has genes A,B and C on one chromsome, and has the alleles a and c on the other chromosome of the pair: A---B---C a---B---c If crossing over occurs between the genes A and B (and not between B and C), then we can get the following genotypes in the gametes, in addition to the above two combinations: : A---B---c a---B---C Crossing over has scrambled the allelic combinations and given us two new additional ones in the gametes. If we allow recombination between B and C, then even more combinations are possible. One can easily see how recombination can add enormous amounts of genetic variation into a population. Also, note that if no recombination occurs, only the two original combinations of alleles will make it into the gametes.
Is it true or false that during meiosis the two alleles for each gene stay together?
False. During meiosis, the two alleles for each gene can separate and be distributed to different gametes. This is known as Mendel's law of independent assortment, which allows for new combinations of alleles to be formed in offspring.
Does sexual reproduction create new alleles or new combinations of alleles?
new combinations of alleles
When alleles on homologous chromosomes move into different gametes during meiosis this demonstrates?
Segregation
What creates different combinations of maternal and paternal chromosomes in gametes?
Independent assortment
Why would two sets of identical twins that marry not have children that look alike?
Even identical twins are heterozygous for many alleles. Recombination would produce gametes with many different combinations of those alleles in each individual. Their offspring, as a result, could have very different genotypes than either parent, and thus look different as well.
During the formation of gametes in a hybrid tall plantthe allele and the short allele stay together?
During the formation of gametes in a hybrid tall plant, the alleles for tall and short height do not stay together. They segregate and assort independently during meiosis, resulting in a random combination of alleles in the gametes. This allows for a variety of possible genetic combinations in the offspring.
Why do zygotes have different allele combinations from the gametes they result from?
When two gametes fuse to make a zygote, cross bridges form between the DNA from the two gametes. During cell division, the two gametes then separate, with some of the parts of gamete 1 being transferred to gamete 2 and vice versa. This recombination allows genetic diversity to occur. A gamete with ABCDE alleles will therefore "recombine" with a gamete with FGHIJ alleles to make, for example, ABHDJ cells. The new sequence will be replicated in subsequent cells.
What is it called when gametes randomly pair to produce different combinations?
sexual reproduction of genotypes
Which does sexual reproduction create new allels or new combinations of alleles?
new combinations of alleles
When alleles for different characteristics are on separate chromosomes they are distributed to gametes independetly this observation summariced the law of?
Segregation.
Skin color in a fish is inherited via a single gene with four different alleles How many different types of gametes would be possible in this system?
it's genotypes not gametes
