The purpose of a presumptive test is to see which substance the sample is.
The correct answer is stabilizing selection reduces the amount of variation in a trait. disruptive selection increases the amount of variation in a trait.
Stabilizing selection is a type of natural selection in which genetic diversity decreases because natural selection favours an average phenotype and selects against extreme variations.
<span>
Disruptive selection is a type of natural selection in which extreme values for a trait are favoured over intermediate values, thus it increases genetic variance.</span>
Answer:
In all organisms, the instructions for specifying the characteristics of the organism are carried in DNA, a large polymer formed from subunits of four kinds (A, G, C, and T). ...
Most of the cells in a human contain two copies of each of 22 different chromosomes. ...
Changes in DNA (mutations) occur spontaneously at low rates.
Answer:
Some mutagens strip DNA nucleotides (bases) of essential modifications—for example, they deaminate the bases—such that these bases resemble different nucleotides and confuse the DNA replication machinery. Subsequent rounds of DNA replication then permanently incorporate such changes.
Explanation: