Answer:
The white hair of a polar bear is an example of adaptation.
Explanation:
Adaptation allows organisms to adjust to their surroundings so that they can survive. Polar bears live in the Arctic region, which is one of the coldest places in our planet. They have sharp teeth and their ears are small to reduce the heat loss. They have a thick coat of insulated fur, which insulates their thick layer of body fat and keeps them warm. They have large paws, that are covered by fur which protects them from sinking in the snow and also provides a good grip on ice. Their coat of white fur helps them to hide from their prey by providing a camouflage in Arctic environments.
Answer:
<u>d. Transport proteins within the membrane serve as a tunnel for molecules to enter the cell.
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Explanation:
Solutes are typically moved across the cell through either passive or active transport. The cells, surrounded by a bilipid layer or plasma membrane is amphiphlic- its polar, hydrophilic lipid heads face outwards, while their non-polar hydrophobic lipid tails face inwards towards each other.
While lipid-soluble molecules move across the layer easily, it is also difficult for charged and also large molecules to move across its surface, into the cell. Transmembrane channels, <u>embedded within the membrane</u>, help to maintain selective permeability as transport proteins, pores and gated channels. Simple diffusion happens as a method of passive transport in cells through plasma membranes.
The solutes travel through the plasma membrane in the process of diffusion from regions of high concentration to regions of low concentration; this occurs without the use of energy. <u>Molecules moving against their concentration require active transport mechanism to cross the membrane</u>.
Answer:
<h2>Concentration Gradient </h2>
<h3>Hope it helps you </h3>
Q1- D
q2- C
q3- B
I am assuming you only need one answer for each, good luck!
