Answer:
Invertebrates have a very quick life cycle and die very easily, as a result, they evolve very quickly into many different types of animals. also, they are often very small and their ecosystems are subject to much quicker change than that of vertebrates, meaning that mutations in their genes become relevant more often. Many invertebrates span very large areas (sea animals span most of the oceans, insects span entire continents) and so they evolve to be different species in different places.
Or
They do not have bones, they live on water or land, they can have soft bodies or exoskeletons, and others are parasites.
The correct answer in multicellular
This process is called Denitrification. The process is undertaken by the denitrifying bacteria, whose action is converting nitrates in the soil to free atmospheric nitrogen and therefore, depleting soil fertility and reducing agricultural productivity. Examples of denitrifying bacteria are thiobacillus denitrificans, micrococcus denitrificans among others.
Answer:
There will be 12 chromosomes
Explanation:
We have given that The epithelial cells in the skin of an animal have 24 chromosomes
We have to find the number of chromosomes present in the gametes of this animal
We know that number of chromosomes present in the gametes is given by
So number of chromosomes in gametes 
