I believe that D is the answer to your question, even though this is a complicated one.
Enzymes are also known as Biological catalysts. An enzyme working at its maximum possible rate, where the substrate concentration is in excess is <span>V max.
</span><span>The reaction is slow because the molecules are moving slowly and they will not often collide with the active site of an enzyme, so the binding of an enzyme and substrate is rare.</span>
Mussels are molluscans and are freshwater animals. The change in the environment led to new traits of mussels, it underwent natural selection and the thick shells have high chances of survival.
<h3>What is natural selection?</h3>
Natural selection is a process of nature that eliminates the organism with less survival and unfit traits while selecting the organisms with better traits of survival in the altered conditions.
The arrival or the introduction of the crabs in the environment altered the previous habitat of the mussels and led to the adaptation of the better trait quality in the mussel species.
The trait of the thick shells underwent natural selection as they were favoured for the changed conditions. The mussel having thick shells have high chances of survival over thin-shelled mussels as the crab will find it hard to attack the thick-shelled mussels.
Therefore, option A. change in environment, option B. natural selection and option E. chances of survival are the correct statements.
Learn more about the natural selection here:
brainly.com/question/10715606
The fir tree can be found in the coniferous forest biome, and the cactus can be found in the desert biome.
Option C.
<h3><u>Explanation:</u></h3>
Both the cactus and fir trees are having modified tree leaves due to the same purpose - saving water.
The fir trees are found in the coniferous forests which are mainly seen in mountains or in the temperate region. Both the regions face very cold climates and frequent snowfalls in every years. This is why there's a lack of water in the surroundings. This is why they need to save water and minimize transpiration.
Whereas the cacti are found in desert or semi arid regions where water is itself very scarce and temperature is either very high or very low. So they have their leaves converted into spines which help to reduce transpiration.