But it was not until 1928 that penicillin, the first true antibiotic, was discovered by Alexander Fleming, Professor of Bacteriology at St. Mary's Hospital in London.
Answer:
B
Explanation:
I believe it is meiosis because there are two parts in which it helps to increase genetic variety. In prophase 1, the genes cross over, which increases the variety. Also, the chromosomes are assigned randomly in Metaphase 1.
Hope this helps:)
Answer:
37.5%
Explanation:
These here are
Black (AA or Aa) and albino (aa)
Agouti (Bb or BB)
Thus, a cross between
AaBb and aaBb
The percent of the progeny which are likely to be agouti would be
A. a. B. b
a. Aa. aa. B. BB. Bb
a. Aa. aa. b. Bb. bb
The probability of agouti would be
1/2 (Aa) * 3/4 (BB or Bb)
= 3/8
= 37.5%
Answer:
A. Yes, because the %A approximately equals the %T and the %G approximately equals the %C in both species.
Explanation:
According to Chargaff's rule, in all cellular DNAs, the number of adenosine residues (A) is equal to the number of thymidine residues (T). And the number of guanosine residues (G) is equal to the number of cytidine residues (C). Therefore, the sum of the purine residues equals the sum of the pyrimidine residues (A+ G= C+ T). It is based on the fact that a purine base always pairs with a pyrimidine base in a double helix DNA.
Chargaff’s rule is followed in all the double-helical DNA molecules irrespective of the species. In DNAs of sea urchin and salmon, the percentage of adenine is equal to that of the thymine and the percentage of guanine is equal to that of the cytosine. Therefore, Chargaff's rule is followed.
Answer:
25%
Explanation:
One out of 4 boxes will have a large B, 25 x 4 = 100, thus your answer is 25%.