DNA - Option C.
Gene - Option A.
Chromosomes - Option B.
<h3><u>Explanation:</u></h3>
DNA is described here as the instructions that governs all the characters of an organism. Its actually a macro molecule which is a polymer of different thousands of nucleotides which is present in all cells and contain genetic information for running the characters of an organism.
Genes are described here as series of nitrogen bases governing a particular character or trait. Gene is actually a functional part of DNA which codes for a protein that governs a particular character of an organism.
Enzymes are proteins in nature. They are produced as a result of transcription and translation from DNA, and hastens different chemical processes of a metabolic activity.
The chromosomes are the condensed form of DNA. They are seen in the cells prior to cell division, either mitosis or meiosis. They are half obtained from father and the other half from mother, leading to variations among the offsprings.
It helps scientists improve on research and tests/examinations to understand the object a little more. For Example: The newer modified microscope helps zoom into harder to see microrganisms. So if technology changed then most of our scientific knowledge wouldve been mistaken this whole time. We wouldnt know many things if technology didnt exist.
B. Density has been decreased Or D.
Radiometric dating depends on radiation from carbon atoms which means only carbon based things can be dated. And life is based on carbon so basically only living things can be dated.
Sample Response:
Bacteria are helpful because they produce oxygen, which our bodies need to breathe, and they help us to digest the food we eat. Bacteria are also helpful because they are used in medicine to help us overcome disease. Bacteria are harmful because they can cause tooth decay and illnesses that can be either common or quite serious.
This is a sample response, so it's 100% correct. Peace!