Why is the Hertzsprung-Russell (H-R) diagram an important tool for astronomers? Select the best answer.

A: it helps them classify stars.

B: it helps them study the life cycle phases of stars.

C: both A and B

D: neither A nor B

Works together in the synthesis, modification, packaging, and transport of lipids and proteins

Jason, a dog breeder, decides to mate a poodle with a golden labrador retriever. he wants to get puppies with the curly hair of the poodle and the color of the labrador. what concept is shown in this example? question 6 options: artificial selection adaptation evolution natural selection

What is it called when part of a cell membrane closes around a molecule to allow the molecule to enter the cell? a. passive transport b.diffusion c. endocytosis d. exocytosisc. endocytosis