A population of mussels was observed in a particular ecosystem. It was found that crabs preferred these mussels as their favorite food. Few mussels developed a thicker shell to protect themselves from crabs found in the region. Which three statements does this adaptation suggest? A change in the environment led to a new distribution of traits in a population. The trait of shell thickening underwent natural selection. The trait for shell thickening will not be selected by future mussel generations. Half of the mussel population developed the trait while the other half did not. Mussels with the shell thickening trait had a greater chance of survival.

Option-1, 2 and 5

Explanation:

In the given question, the evolution of Muscles in response to natural selection pressure that is crabs has been given.

In the given question, since the Mussels produced the thick crabs, therefore, the Mussels adapted to the natural pressure and increased their reproductive rate.

These Mussels now reproductively isolated grew to a larger number and a new trait is distributed in the population.  

The Mussels with the thicker shell has higher reproductive rate as the crabs are unable to eat them.

Thus, the selected options are correct.

answer: the blood-brain barrier is a layer of specialized membranes and cell processes designed to keep undesirable substances from passing from the bloodstream into the precious tissues of the brain. while the blood-brain barrier does keep most bad things out of the central nervous system, it is not impermeable.

explanation:

it has to be understood that the sea water contains a huge amount of sodium and chlorine ions and if they enter the cell of the atlantic cod fish, the cell will shrivel and the fish will die. to avoid such a condition, the fish uses active transport for the purpose of removing the ions against the gradient.

explanation:

the atlantic cod is not a maritime osmoconformer. its native application of salts is less than that of the seawater it lives in. it is continually falling water from the gills to the ocean via osmosis.

countering that, the fish is going to be swallowing seawater. but since its internal collection of salts is lower than seawater, the fish will want to go free of excess salt, and since that's going upon a gradient, then active transport, requiring energy, must be used to pump out the salt. much marine fish use the organs to filter out the salt and these fish discharge very straight urine.