Answer:
c. The harmless bacteria had been transformed.
Explanation:
Fredrick Griffith carried out the first experiment that showed bacteria can get DNA by transformation in 1928.
He used two different strains of the bacteria Streptococcus pneumoniae a)type-III-S or smooth strain-Covered by a protective polysaccharide capsule hence lethal
b) type II-R or rough strain-Lacked the polysaccharide hence non-lethal
In his experiment he observed heat killed Type-III-S strain was not able to kill the mice. However, when its remains was added with rough strain then the blend was able to kill the mice.
When he collected blood from the dead mice it had live strains of both smooth and rough type.
He came to a conclusion that non-lethal type II-R strain was transformed into lethal type II-S strain by a "transforming principle" that was supposed to be the part of dead III-S strain bacteria.
50 percent of the offspring would be expected to have the ability to roll their tongues If a heterozygous male is crossed with a homozygous recessive female.
Explanation:
Information given:
the ability to roll tongue is dominant, the genotype would be RR, Rr
the inability to roll tongue is recessive trait the genotype = rr
Given that heterozygous male is crossed with homozygous recessive female, the genotype is
Rr X rr
Punnet square shows that:
R r
r Rr rr
r Rr rr The genotype ratio is 1:1
phenotype ratio is 1:1
There are chances of 50 % offspring having the ability to roll their tongues as they are heterozygous and have the dominant allele for rolling of tongues.
Waxing gibbous Moon is correct
