D: needs to be present on both chromosomes to be expressed
Why: Because if there was a dominant trait present, then the dominant trait would overpower the recessive trait regardless of the matter.
The terrestrial gastropods are the only mollusks that have adapted to all the habitats of the Earth. They dwell in areas of high altitude, mountainous regions, hot and cold places. Land snails live and perform their vital functions on the ground and not in the sea or bodies of fresh water.
Answer:
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Explanation:
Many of these diseases can be prevented by the use of viral vaccines, which stimulate protective immunity against the virus without causing major disease. Viral vaccines may also be used in active viral infections, boosting the ability of the immune system to control or destroy the virus.
Robert Hooke observed the thin slice of cork cells present in the plant cells. In 1665, Robert Hooke referred these empty tiny box-like cavities as cork cells.
<h3>What is Robert Hooke's Observation?</h3>
In 1665, Robert Hooke used a microscope to examine a tiny box-like empty cavities which are referred to as cork cells. He observed that the cork was made up of tiny units that looked like a honeycomb. He referred to them as cells, and he was the first to find a dead cell. This observation has a major contribution in the cell theory.
Hooke published his results under the title Micrographia, about his microscopic observations on several plant tissues. He is remembered as the coiner of the word “cell,” referring to the cavities he observed in thin slices of cork. The cork cells protect the tree from bacterial or fungal infection. It prevents water loss through the bark.
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