Loss of habitat from any number of causes is the main reason for species endangerment currently.
All the cells don't have all of the intracellular structures because each and every cell do not need each and every intracellular structure. The plant cells have chloroplasts because they need to convert the light energy into chemical energy via the process of photosynthesis, the animal cells, however, have no such need, therefore, the animal cells do not have chloroplasts. Also, the erythrocytes do not have the cellular organelles in them which are present in the other body cells, because there is no need for the cellular organelles in them. The large vacuoles in plant cells is also a great example. The plants need the vacuoles for the metabolic processes, while most animal cells have no need for them.
Answer:
answer a is trash answer b add a vertical line
Explanation:
<span>The gene sequence containing an operator, promoter and repressor is known as an operon. These genes are called as structural genes. the operon is regulated by the presence/absence of the inducer such as glucose/lactose. It may also be a constitutive operon, which works all the time.</span>
