the cell membrane is selectively permeable. o2 diffuses across the phospholipid bilayer. k+ must cross the cell membrane using a membrane protein. which property of the cell membrane prevents the diffusion of k+?

a) the membrane proteins are attracted to the charged ions.

b) only very small particles are able to diffuse across the cell membrane.

c) the lipid tails are hydrophobic, repelling charged ions such as k+.

d) the phosphate heads are hydrophobic and prevent the passage of polar substances.

The answer is C.The lipid tails are hydrophobic, repelling charged ions such as K+.

Option C is correct

Explanation:

The phospholipids layer of plasma membranes consists of both water attracting and fearing regions due to which some elements easily pass through this membrane while some face obstruction. All charged molecules (such as metal ions) and polar molecules like water are not allowed through the lipid tail. Water interacts with the hydrophilic head effectively but does face issues in passing through the hydrophobic head region. Also all metal ions like potassium, calcium, sodium etc. and non-metallic ions such as chlorine cannot pass through the membrane.  

Hence, option C  is correct

well, that's easy; the answer's c, "it reduces contamination of the water and substrate of the estuary."

1: most common garden plants prefer loam — soils with a balance of different-sized mineral particles (approximately 40% sand, 40% silt, and 20% clay) with ample organic matter and pore space. however, some plants grow better in sandy soils, while others are well-adapted to clay soils.

2: available water capacity is the maximum amount of plant available water a soil can provide. it is an indicator of a soil's ability to retain water and make it sufficiently available for plant use. available water capacity is the water held in soil between its field capacity and permanent wilting point.

3: it is the same for all living things (plants and animals). it also includes very tiny organisms that our eyes cannot see. they are known as microorganisms, and include viruses, bacteria and fungi.