B. Increased exposure to UV light increases the risk of mutation occurring.
Circulatory system
The circulatory system is the transport system for endocrine information. While the nervous system uses neurons, the endocrine chemicals and hormones must circulate through the body via blood vessels. Many glands in your body secrete hormones into the blood.
The correct answer is d. morula.
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A morula is a stage in early development, formed 3–4 days after fertilization. It is a 16-cell mass which forms a solid ball contained within the zona pellucida. A morula develops into a blastocyst.</span>
Generally, epithelial cells serve the function of protection of the inner layers of the structure they are on. The fact that these columbar epithelium and transitional epithelium cells have smooth walls and are dome shaped allows them to stretch. This stretching helps the bladder retain more urine than it would be able to if the epithelial cells were rigid.
