Answer:
Please find the expected genotypes and phenotypes of the progenies of each cross below.
Explanation:
In the MN blood-group locus of the gene, alleles LM and LN exhibit codominance i.e one allele is not dominant or recessive to the other, hence, they are both expressed when they occur in a heterozygous state (MN).
Considering the following crosses (find the punnet square attached);
a)LMLM x LMLN - The progeny are LMLM and LMLN in the genotypic ratio 1:1. Phenotypic ratio is Blood type M (1) : blood type MN (1)
b) LNLN x LNLN - The progeny are all LNLN offsprings with a phenotypic and genotypic ratio 4:0. All offsprings will have a blood type N (4)
c) LMLN x LMLN - The progenies are LMLM, LMLN and LNLN in the genotypic ratio 1:2:1 respectively. The phenotypic ratio is Blood type M (1) : L
Blood type MN (2) : Blood type N (1)
d) LMLN x LNLN - The progeny are LMLN and LNLN with genotypic ratio 1:1 and phenotypic ratio blood type MN (1) : blood type N (1)
e) LMLM x LNLN - The progeny are all LMLN offsprings with penotypic ratio blood type MN (4)
Answer:
12:3:1
Explanation:
<em>The typical F2 ratio in cases of dominant epistasis is 12:3:1.</em>
<u>The epistasis is a form of gene interaction in which an allele in one locus interacts with and modifies the effects of alleles in another locus</u>. There are different types of epistasis depending on the type of alleles that are interacting. These include:
- Dominant/simple epistasis: Here, a dominant allele on one locus suppresses the expression of both alleles on another locus irrespective of whether they are dominant or recessive. Instead of the Mendelian dihybrid F2 ratio of 9:3:3:1, what is obtained is 12:3:1. Examples of this type of gene interaction are found in seed coat color in barley, skin color in mice, etc.
- Other types of epistasis include <em>recessive epistasis (9:3:4), dominant inhibitory epistasis (13:3), duplicate recessive epistasis (9:7), duplicate dominant epistasis (15:1), and polymeric gene interaction (9:6:1).</em>
I think its called glacier. Hope I helped
Reproductive system and it's functions