Answer:
A)The limb bones are similar across these species because they share a common ancestor.
Explanation:
The forelimb of humans, horses, goats, and mice are homologous organs. Homologous organs are those which are similar in origin but dissimilar in function. These organs are made of the same bones humerus, ulna, and radius. The above for limb in the given animals perform different functions as they live in different habitats. The homologous structures indicates divergent evolution.
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.
The thyroid is a butterfly-shaped gland that lies in front of the windpipe (trachea), just below the voice box. The parathyroid glands are four tiny glands located behind the thyroid gland. The parathyroid glands produce a substance (parathyroid hormone) that helps control the amount of calcium in the blood.
The substance is called DNA.