I believe the answer would be D. If a plant were to have poisonous parts it could me the possibility that a child could become seriously ill.
The epiglottis is a flap in the back of your tongue that prevents food from entering the larynx. When your mouth is closed, the epiglottis is in place and blocks the larynx opening. If your mouth is open, the flap lifts and the larynx is no longer blocked so you can breathe. This is why it's important to not chew with your mouth open... if you do, then food can go down the larynx by mistake.
Answer;
Amino acid side chains have many carboxyl and amino groups.
Explanation;
-A buffer solution is a solution that resists changes in pH when small quantities of an acid or an alkali are added to it. It is a chemical substance that helps maintain a relatively constant pH in a solution, even in the face of addition of acids or bases.
-Buffering is important in living systems as a means of maintaining a fairly constant internal environment, also known as homeostasis.Small molecules such as bicarbonate and phosphate provide buffering capacity as do other substances, such as hemoglobin and other proteins.
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Protein buffer systems depend upon proteins, as opposed to nonprotein molecules, to act as buffers and consume small amounts of acid or base. Since amino acids have the capability of reacting with both acid and base, they naturally act as buffers.
Answer:
The correct answer would be d. thymus.
The thymus is a specialized lymphoid organ of an immune system.
It serves as the site for training and maturation of T-lymphocytes or T cells.
It is composed two identical lobes each containing outer region termed as cortex and inner region termed as medulla.
T-cells are first trained and selected in the cortex region via positive selection. In this, T cells which are able to bind to foreign antigens are selected and rest are degraded.
The selected T cells then move in the medulla region where they are selected by negative selection. In this, the T cells which binds to self-antigens are degraded and rest survive to become functional T cells.