Answer: The correct answer is - 3) olfactory receptors neurons that detect smell. 4) photoreceptors neurons that detect light .
1) and 2) statements are correctly matched in the question..
Olfactory receptors are also called odorant receptors. The olfactory receptor neurons detect smell and thus give a sense of smell to the organism. They are present in the nasal cavity.
Photoreceptor neurons are those that detect light and they are present in the retina of eye.
Answer:
B. The membrane lets certain substances move across it freely, while others must move through a “gate”.
Explanation:
Selective permeability is a property of cellular membranes that only allows certain molecules to enter or exit the cell. This is important for the cell to maintain its internal order irrespective of the changes to the environment. For example, water, ions, glucose and carbon dioxide may need to be imported or exported from the cell depending on its metabolic activity. Similarly, signaling molecules may need to enter the cell and proteins may need to be released into the extracellular matrix. The presence of a selectively permeable membrane allows the cell to exercise control over the quantum, timing and rate of movement of these molecules.
The answer is <span>B. immune cells that are destroyed by HIV
CD4+ are immune cells (white blood cells) and are an important part of the immune system. Their name comes from the presence of CD4 glycoprotein on their surface. HIV uses CD4 glycoproteins on the surface of CD4+ cells to entry into the cells. The consequence is a reduced number of those cells. Therefore, CD4+ immune cells are destroyed by HIV.</span>
Interphase and cytokinesis are preparing the cell to go through mitosis and multiply
