The correct answer is the second option. Animals have two major types: vertebrates and invertebrates. Vertebrates are animals that have backbone while the invertebrates do not have one. Examples for vertebrates are birds and mammals while the latter are insects and squid.
Nucleosus is the correct answer to the question
I believe glycogen is an example of a complex carbohydrate or polysaccharide.
Answer: C. competition for nest sites between beetles and owls
