Answer: B, C and, D
It allows nutrients to enter the cell.
It provides a barrier against disease-causing agents.
It enables cells to interact with their environment.
Answer: <u>B. They signal phagocytes
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Explanation: Complement proteins are a part of immune system of the body. These are plasma proteins which help in the process of marking and killing the pathogens. These are not involved in the fever causing mechanism, so option D is incorrect. Also, these are not carrier proteins, and are not associated with hormones, thus option C is also incorrect. Since these proteins bind with the pathogens and make them easily recognized by the phagocytes, option B is the right answer.
The correct answer is (D) Penguins and ducks develop in a more similar way since their common ancestor is more recent than the common ancestor of penguins and bats or ducks and bats.
The birds such as penguins and ducks develops in a similar way since their common ancestors are more recent as compared to the common ancestors in case of penguins and bats or in case of ducks and bats. The birds and bats do not share any recent common ancestors according to the phylogenetic tree.
In an atom, the nucleus is composed of protons and neutrons, while the electrons orbit very quickly around the nucleus.
