Answer:
Gene mutations provide new alleles, making these mutations the ultimate source of variation. A gene mutation is an alteration in the DNA nucleotide sequence, producing an alternate sequence, termed an allele. Mutations occur at random, and can be beneficial, neutral, or harmful.
Explanation:
The four most abundant elements needed by the human body are carbon, hydrogen, oxygen, and nitrogen because these are needed in large amounts to support our cells, these are referred to as bulk elements.
Oxygen is the most essential element required by our body. The body requires oxygen in the form of gas which is inhaled by the air around us. All the cells in a human body require oxygen which is transported by the blood inside.
Cell is the most basic and fundamental unit of life. It can be of two types: prokaryotic and eukaryotic. Prokaryotic cell is the primitive one with no true nucleus and eukaryotic cell has a true nucleus and all the cell organelles. Generally eukaryotic cells require abundant amount of oxygen.
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It pushes its stomach outside its body.
Natural killer (NK) cells are also called cytotoxic T cells (Option A).
<h3>What are NK cells?</h3>
The NK (Natural killer) cells are cytotoxic lymphocytes that trigger responses from the innate immune system.
Natural killer cells are one of the most important types of lymphocytes (white blood cells) in human cells.
These cells have cytotoxic properties because they produce cytotoxic granules and different cytokines.
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