What is dominant epistasis in summer squash?
A dominant epistasis is a condition when a dominant gene masks the effect of the other non-allelic gene. In summer squash, the fruit colour may be white, yellow or green. White fruits are produced by a domain epistatic allele ‘W’. At another locus, Y for yellow fruits is dominant to its allele y for green fruits.
What color in squash is dominant?
1. In summer squash, white fruit color is dominant over yellow. If a plant homozygous for white fruit color is crossed with a plant homozygous for yellow fruit color, what will the F1 generation be like?
What would the phenotype of a WwYy squash be?
However, if a dominant copy of the W gene is present in a homozygous or heterozygous form, the summer squash will produce white fruit irrespective of the Y alleles. The phenotypes will be WwYy and Wwyy will be white because the white gene is dominant and the W gene is epistatic.
What is recessive epistasis?
Recessive epistasis is the phenomena in which the expression of one gene pair is dependent on another gene pair (OpenStax College, 2013). In other words, one gene must be turned on for another gene to be expressed. Three phenotypes result from recessive epistasis in a 9:3:4 ratio (Miko, 2008).
What is epistatic and hypostatic explain the dominant epistasis with an example?
The gene that suppresses or masks the phenotypic expression of a gene at another locus is known as epistatic. ‘W’ allele is dominant that masks the expression of any colour. Dominant epistasis in summer squash In another locus hypostatic allele ‘G’ is for yellow fruit and its recessive allele ‘g’ for green fruit.
Which set of parents can most likely produce a child with blood type O?
Question 3. Remember, because type O blood results from the homozygous recessive genotype (i i ), the only way to produce a type O child is if both parents provide an O allele (i ). Since the father has blood type A, he must be heterozygous (IA i ).
How can you tell if a epistasis is dominant or recessive?
Dominant epistasis is when only one allele of the gene that shows epistasis can mask alleles of the other gene. Recessive epistasis is where two alleles have to be inherited in order for the phenotype of the second gene to be masked.
What is a recessive epistasis?
What is the genotype for disc shape squash?
The possible gametes are WD and wd. Thus, a cross between these two gametes would result in a F1 progeny having a genotype of WwDd, and phenotype of white colour with disk-shaped fruit.
What’s the difference between recessive and dominant epistasis?
The interactions between genes are antagonistic in epistasis, one gene masking the expression of another. In dominant epistasis, the dominant allele of one gene masks the expression of all alleles of another gene, whereas, in recessive epistasis, the recessive alleles of one gene mask the expression of all alleles of another gene.
Is there a Punnett square for recessive epistasis?
This is a Punnett square for recessive epistasis. GeneA shows epistasis over GeneB; however, GeneA can only mask the phenotype of Gene B when two recessive copies are inherited. Like bullies that travel in packs, genes that show recessive epistasis are powerless when they are alone.
When does a dominant gene MASK a recessive gene?
When a dominant allele at one locus can mask the expression of both alleles (dominant and recessive) at another locus, it is known as dominant epistasis. In other words, the expression of one dominant or recessive allele is masked by another dominant gene. This is also referred to as simple epistasis.
Which is the dominant phenotype of yellow squash?
Three individuals will show the dominant (AA, Aa) yellow phenotype, and one individual will show the recessive (aa) green phenotype. Remember that yellow and green squash are always have a bb phenotype because GeneB shows dominant epistasis.