Answer:
c. ¼ heavy, ¾ light
Explanation:
DNA replication follows semi conservative model which means that both the strands separate during replication and the newly formed DNA molecule has one old and one new strand. If instead of semi conservative, conservative mechanism is used, old strands will not separate from each other and the two newly synthesised DNA strands will come together to form a DNA molecule.
Here the cells were first grown in heavy 15N medium so all the DNA molecules had 15N and thus were heavy. Then the cells were transferred to 14N medium where only lighter 14N were available for replication process.
In first generation, 14N DNA molecules were synthesised from 15N DNA molecules so 1/2 DNA molecules were 15N and other half were 14N. In the second generation, 14N molecules will give rise to new 14N molecules and 15N molecules will also give rise to 14N molecules hence 1/4 molecules will be 15N (heavy) and 3/4 will be 14N (light).
Genetic variation is an important force in evolution as it allows natural selection to increase or decrease frequency of alleles already in the population. ... Genetic variation is advantageous to a population because it enables some individuals to adapt to the environment while maintaining the survival of the population.
It would be d because you could get it again but it would be a different kind
Filtered blood leaves the kidney through the renal vein and flows back to the heart. Pee leaves the kidneys and travels through the ureters to the bladder. The bladder expands as it fills.
Answer:
a variety of genes are involved in the control of cell growth and division. the cell replicates itself in an organized, step by step fashion known as the cell cycle.
Explanation:
tight regulation of this process ensures a dividing cell's DNA is copied properly, any errors in the DNA are repaired and each daughter cell receives a full set of chromosomes.