DNA and Genes are linked because dna is made up of genes in one way or another
<u>Answer:</u>
Cyanobacteria start producing pure oxygen around 200 million years ago.
<u>Explanation:</u>
Many scientists believed that Earth did not have any oxygen. Cyanobacteria or the blue green algae are the microbes which produced oxygen for the first time with the help of photosynthesis. This was around 4.5 billion years ago: after Hadean eon.
They were very simple, but they produced oxygen in the early earth’s atmosphere. So, they brought evolution on earth. This “blue-green algae” exists in salt water, rocks and soils and play a major role in maintaining the ecosystem.
Answer:
1:1:1:1 walnut comb
Explanation:
If a cross is made between a female who is RRpp (rose comb) and a male who is rrPP (pea comb) then:
P: RRpp x rrPP
F1: RrPp RrPp RrPp RrPp
This means that all of the offspring in F1 generation will have heterozygous genotype (at both loci). Since it contains both dominant alleles, the phenotype is walnut comb.