The answer is <span>insect and pest populations decreased.
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DDT (dichlorodiphenyltrichloroethane) was used as an insecticide which is a substance used to kill insects. That resulted in decrease in insect and pest populations. It is a persistent and non-degradable insecticide, but as well organic pollutant readily accumulated to soils and consequently affects organisms.
Had to look for the options and here is my answer. The answer that fits the blank is SPATIAL NEARNESS. When we say spatial nearness, this refers to small distance or closeness and marital homogamy becomes a choice in marriage. <span>Marital homogamy refers to the relationship wherein someone marries another who are of the same sociological status.</span>
Answer:
The correct answer would be - 50%.
Explanation:
Hemophilia is a sex-linked recessive disorder that takes place in males more than in females as females have two X chromosomes so if one is affected other still able to make clotting factors but in males, there are only one x chromosome.
If a hemophilic man XhY marries with a carrier women XHXh then the chances of their son for normal blooding would be :
Gametes:
Male: Xh and Y
Female: XH and Xh
Then cross:
Xh Y
XH XHXh XHY
(carrier daughter) (normal son)
Xh XhXh XhY
(hemophilic daughter) (hemophilic son)
Thus, the chances of normal son is 50% among sons
<span>The correct answer is Yes. more than two possible alleles for a single gene type is called multiple allelism. the alleles for the abo blood types are an example.</span>
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It is possible to exist more than two alleles for a single gene within the population, but individuals have only two of those alleles (each from one parent).</span>