The correct answer is - due to the law of segregation.
Explanation:
In the given case the genotype of Rr and as we know R is a dominant characteristic for round seeds and r represents the recessive allele for wrinkled seeds in a pea plant. So if a plant has Rr in its genotype it means it is a phenotypically round pea plant due to dominance in this heterozygous case.
The law of segregation states that two alleles of a gene of a specific trait will be distributed randomly and there is an equal chance of each allele to end up in the gametes, similarly in this case both alleles can be segregated to gametes and it is a random process.
Connective tissue serves to 'connect' or 'bind' the cells of other tissues in the body and gives them rigidity and support. Areolar connective tissue is of two types - white fibres (made of collagen) and yellow fibres (made of elastin).Tendon is made up of white fibres and connects muscles to bones
The organism previously used 15N for replication so all the DNA molecules were of 15N15N type. Then the organism is shifted to a medium where only 14N is available for replication.
According to semi conservative mode of replication, a newly synthesised DNA molecule consists of one new strand and one parental strand. So after the first round of replication, All the 15N strands will synthesise new DNA strands using 14N resulting into intermediate 15N14N DNA molecules. Hence, only one band would be observed (15N14N) above the original 15N15N band since 15N14N has lighter isotope too so it will be lighter than 15N15N molecules and will lie above it.
After second round of replication, 15N strand from 15N14N would synthesise another 14N strand. 14N strand from 15N14N molecules will also synthesise another 14N strand. So now, 50% of the DNA molecules will be of 15N14N intermediate type and 50% of them will be of 14N14N type.Two bands will be observed above the original 15N15N band. One band of 15N14N molecules will be right above it and other band of 14N14N molecules will be even higher because it is the lightest band since it has only the lighter isotope of nitrogen.
