True
DNA are cells that carry genetic codes and are passed down through generations of offspring. New cells can only arise from existing cells!
Answer:
The correct option is option A
Explanation:
Restriction enzymes are endocleases that cleave DNA fragment (<u>of usually four, five or six nucleotide long</u>) at <u>specific sites to produce blunt or sticky ends</u>. They <u>recognize palindromic sequences of host DNA when cleaving the specific sites</u>. The sequences below (on complementary strands) give an example of a palindromic sequences.
5'-CCC║GGG-3'
3'-GGG║CCC-5'
As can be seen above, when read from 5' to 3', the two sequences are the same despite being on opposing strands. And when cut between the guanine (G) and cytosine (C) (as shown above), it produces a blunt end. But when cut as shown below produces a sticky end.
5'- G║AATTC -3'
3'- CTTAA║G -5'
The explanation above shows options C and D are right while option A is wrong (hence the correct option).
Also, bacteria prevent their own DNA from been digested by restriction enzymes by adding methyl group to their restriction sites <u>which prevents restriction enzymes from recognizing restriction sites of their DNA;</u> this generally makes bacterial DNA to be highly methylated. This explanation makes option B right also.
Answer:
<h2>Recessive to
</h2>
Explanation:
1. As given here, both parents are black, and their 247 progeny out of 333 are black, it clearly indicates that 3/4 progeny is parental phenotype and 1/4 is different type.
2. This clearly show that both parents are heretogyzous, one allele is dominant and one is recessive.
3. Here black is dominant over blue.
4. Dominant allele express them-self in dominant homogyzous as well as heterogyzous condition.
