Answer:
the fundamental unit of heredity
Explanation:
DNA is a double stranded helix structure. Each strand is made up of a string of nucleotides.
A gene is a region of DNA, usually tens of thousands of nucleotides long. At the simplest level, one gene encodes for one trait. Therefore, the gene can be described as the fundamental unit of heredity.
Genes work by coding for specific proteins, which carry out essentially all the functions in the cell.
The answer is <span>d. homologous structures.
Homologous structures are </span><span>similar structures shared by different species. For example, the anatomy of joints in bones of birds and dinosaurs, support the idea that these two groups have a common ancestor. But since these two groups are different enough to be separated into different classes, it can be concluded that they evolved from the common ancestor.</span>
The connection between them is Vitamin D.
Vitamin D can be obtained from food and supplements, or synthesized by our bodies when we receive UV radiation in our skin, which is our major source. However, this vitamin comes <span>inactivated</span> and the only way to activate it is through enzymatic conversion (hydroxylation) in the liver and later in the kidneys.
This vitamin is necessary in the intestines because allows calcium and phosphorus to be observed, leading to normal growth and development of bones and teeth. Without enough vit D, bones become fragile, causing osteoporosis.
Echinoderms have radial symmetry.
Answer:
chloroplasts
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