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)

6 0

3 years ago

A population of salamanders lives near a stream. A severe drought dries up the flow of the stream. What is this effect on the sa

sertanlavr [38]

Answer:

limiting factor

Explanation:

In an ecosystem, certain factors hinder the growth or abundance of the population of organisms. These factors are called LIMITING FACTORS. Limiting factors, which can be biotic, food, drought, predation, disease etc, are factors that inhibits a population of organism from becoming enlarged. There are two types of limiting factors viz: density dependent (depends on size) and density independent (not dependent on size).

This is the case of a drought that dries up the stream that inhabits a population of salamanders. The drought causes the unavailability of water, which will ultimately have an effect on the growth of the salamander population. Hence, the DROUGHT is considered a LIMITING FACTOR.

7 0

2 years ago