In the the fruit fly drosophila, there is a dominant gene for normal wings and its recessive allele for vestigial wings. at another gene locus on the same chromosome, there is a dominant gene for red eyes and its recessive allele for purple eyes. a male that was heterozygous at both gene loci was mated with a female that was homozygous for both recessive alleles and the following results were observed among the offspring:

normal wings and red eyes - 420
vestigial wings and red eyes - 80
normal wings and purple eyes - 70
vestigial wings and purple eyes - 430

according to these data, what is the distance, in centimorgans, between these 2 gene loci? (enter the number only without the units. for example, 100 cm would be entered as 100)

15

Explanation:

According to linkage theory, two genes present on the same chromosome tend to get inherited together. So the gametes produced are not equal in number and parental type offspring are observed more in number than the new recombinant types.

Here, normal wings, red eyes (420) and vestigial wings, purple eyes (430) are most in number hence they are the parental type offspring.

Vestigial wings, red eyes = 80 : recombinant

Normal wings, purple eyes = 70 : recombinant

Distance between two genes in cM = recombination frequency = (total number of recombinants / total progeny)*100

= [(80+70)/(420+80+70+430)]*100

= (150/1000)*100

= 0.15*100 = 15cM

estuaries are the partially enclosed coastal bodies of brackish water formed at the mouth of sea where river meets an ocean. it is a transition zone between river and sea water so estuaries are influenced to both marine environment such as tides, waves and to riverine such as flow of fresh water and sediments. the mixing of sea and fresh water provide high level of nutrients, making estuaries a high product habitats.

many estuaries suffers degradation from a variety of human activities like erosion from deforestation, overgrazing, overfishing, drainage and eutrophication.

so from the above statement answers will be

1. false as estuaries are formed due to both brackish and freshwater.

2.true, due to high productivity estuaries are breeding ground for many marine species.

3. direct and indirect activities of man that contribute to pollution and deposition of sediments.