Which event can directly produce one chromosome containing both maternal and paternal genes?
This process is called recombination, or crossover, and it is a common genetic process. Because the genes are aligned during recombination, the gene order is not altered. Instead, the result of recombination is that maternal and paternal alleles are combined onto the same chromosome.
What is the probability of these heterozygous parents producing an offspring who carries an allele for albinism?
Autosomal recessive inheritance
This means a child has to get 2 copies of the gene that causes albinism (1 from each parent) to have the condition. If both parents carry the gene, there’s a 1 in 4 chance that their child will have albinism and a 1 in 2 chance that their child will be a carrier.
What is the probability of heterozygous parents carrying the recessive allele for albinism producing an offspring who expresses the albino phenotype?
Using the information provided in this figure, what is the probability of these heterozygous parents producing an offspring who carries an allele for albinism? In this Punnett square, 75% of the possible offspring will carry the recessive allele a in the genotype.
Which form of inheritance most often results in a recessive trait being expressed more often in males than in females?
Patterns of inheritance
Second, X-linked recessive traits are more commonly expressed in males than females. This is due to the fact that males possess only a single X chromosome, and therefore require only one mutated X in order to be affected.
Why is crossing over important?
Crossing over is important for the normal segregation of chromosomes during meiosis. Crossing over also accounts for genetic variation, because due to the swapping of genetic material during crossing over, the chromatids held together by the centromere are no longer identical.
What is the term for the breeding of parents when only one trait is being investigated?
This technique, which involves looking at a single trait, is today called a monohybrid cross. The resulting F2 generation had seeds that were either round or wrinkled.
What is the probability that they will have an offspring who is heterozygous for both traits?
Offspring heterozygous for both traits
There are 4 out of 16 possible combinations of gametes from an SsYy x SsYy cross with the genotype of SsYy. We would therefore predict that 4/16 (or 1/4) of the offspring of the cross would be heterozygous for both traits.
What is the probability of two heterozygous parents having a heterozygous offspring?
The chance of either parent being a heterozygote is 1/4, as calculated above. Then, the probability that both parents are heterozygotes, and the probability that two heterozygotes will have a heterozygous child, is 1/4 x 1/4 x 1/2 = 1/32.
What is the probability of having offspring that are homozygous dominant for both traits?
If two homozygous dominants are crossed, the probability that an offspring will be homozygous dominant is 100% or 1.00.
What happens when both parents have recessive genes?
When both parents are carriers for a recessive disorder, each child has a 1 in 4 (25 percent) chance of inheriting the two changed gene copies. A child who inherits two changed gene copies will be “affected,” meaning the child has the disorder.
Can two parents with dominant traits produce an offspring with recessive trait Why?
Only individuals with an aa genotype will express a recessive trait; therefore, offspring must receive one recessive allele from each parent to exhibit a recessive trait. One example of a recessive inherited trait is a smooth chin, as opposed to a dominant cleft chin.
What is the difference between heterozygous and homozygous individuals?
Homozygous: You inherit the same version of the gene from each parent, so you have two matching genes. Heterozygous: You inherit a different version of a gene from each parent. They do not match.
What type of allele will be expressed if both dominant and recessive alleles are present for a given trait?
If both alleles are dominant, it is called codominance?. The resulting characteristic is due to both alleles being expressed equally. An example of this is the blood group AB which is the result of codominance of the A and B dominant alleles.
Why are some genes dominant and others recessive?
Dominant refers to the relationship between two versions of a gene. Individuals receive two versions of each gene, known as alleles, from each parent. If the alleles of a gene are different, one allele will be expressed; it is the dominant gene. The effect of the other allele, called recessive, is masked.
Can recessive genes become dominant?
Many recessive traits could become dominant with the right DNA tweak. This kind of dominant gene version is called a dominant negative.