B. White petal colour is a recessive trait.
Explanation:
In Mendelian genetics, the alleles depicted in small letters are recessive traits.
Since both alleles are same and in lower case they are homozygous recessive alleles for a white coloured petal gene.
The genotype of the trait will be tt because if it is crossed either with heterozygous or homozygous P alleles it will appear as tt to have phenotypic trait of white colour.
So the genotype will be tt.
Answer:
The correct answer is option B. favorable change in DNA of the insect.
Explanation:
At the point when a pesticide is first utilized, a little extent of the pest population may survive to introduction to the material because of their particular hereditary or genetic makeup. These surviving individuals pass along the gene resistance to particular insecticide or pesticide to next generation.
Upon introduction to pesticides, insects that don't have the resistance die eventually, in this manner permitting the insects with the resistance genes to endure and reproduce,creates more resistance insects.
Thus, the correct answer is option B. favorable change in DNA of the insect.
The answer is <span>-Only the few bacteria that were immune to the antibiotic survived and reproduced, making all their offspring immune to it as well.
Bacteria (or any other organism) are not able to make changes to their DNA in order to protect themselves or to learn to remove the receptors on their cell surfaces. If they were able to produce toxins against the antibiotics, they would all survive.
These leave the second choice as the correct answer. This is the real situation, and is a good example of natural selection.</span>
Answer:
(i)
x= nucleus
y= chloroplasts
z= vacuole
(ii)
1) an animal cell does not contain a vacuole but a plant cell does
2) a plant cell contains chloroplasts but an animal cell does not
