Answer:
c. A bacterial cell that lacked receptors on its surface for that antibiotic
Explanation:
If the bacteria lacks the receptors on its surface meant for that antibiotic then it will be best defense for the survival of that bacteria. It is receptors which interact with the antibiotic so as to permit it inside the cell. Therefore, in the absence of receptors, it doesn't matter how much antibiotic is lying in the external environment of that bacteria, the antibiotic will not be able to enter the bacterial cell to kill it. Hence, the bacteria will be able to survive easily.
Answer:
Option B, Rr pp × rr Pp
Explanation:
Given
Walnut Comb is produces when one dominant allele R is present at one gene locus and at least one dominant allele P is present at a second gene locus - R* P*
Rose Comb - at least one dominant allele is present at the first locus and two recessive alleles are present at the second locus - R* pp
Pea comb - two recessive alleles are present at the first locus and at least one dominant allele is present at the second - rr P*
Single comb - two recessive alleles are present at the first and the second locus - rrpp
Parent are rose combed and pea combed
For being rose genotype must be R* pp
and for being pea combed genotype must be rr P*
Rr pp x rr Pp
will produce
Walnut comb with genotype Rr Pp
Single comb with genotype rrpp
and pea comb with genotype rrPp
Hence, option B is correct
