Answer:
D. the dynamic regulation of an organism's internal environment to maintain conditions suitable for survival.
Explanation:
it can show us our history and may help us discover relatives we never new we had or lot contact with.
Always start with the genotypic ratios, because they'll be the same. Since hidden variation is popping out, you can assume that both of the parents are heterozygous. The problems you get will be the F2 ratio of the cross between two homozygous individuals.
1:2:1 is the genotypic ratio for one locus. AA:Aa:aa.
1:2:1 is the phenotypic ratio for incomplete dominance. Incomplete dominance means that the heterozygote expresses differently from either homozygote.
3:1 is the phenotypic ratio for complete dominance.
2:1 is the phenotypic ratio for lethal recessive.
Answer:
The correct answer will be option-A.
Explanation:
Lac operon is a set of genes arranged sequentially for lactose metabolism in E.coli. The lac operon gets activated in the presence of lactose as the lac operon consists of three enzyme coding genes called lacZ which codes for the β-galactosidase enzyme, lacY which codes for lactose permease, lacA which codes for acetyltransferase along with a regulatory gene called lacI which codes for repressor proteins.
The repressor proteins bind to the operator and control the transcription. When it binds to operator its huts off the transcription. If a mutation occurs in the laci gene then the protein will lose the machinery which will turn off the activity of enzymes and will lead to the constitutive expression of the genes irrespective of the inducer present or not.
Thus, option-A is the correct answer.
