Which substance is considered a building block for all living things?

About __ of the mass of the cell is water

Which of the following best describes a human sperm cell? A haploid cell formed in the male testes A diploid cell formed in the male testes A haploid cell formed in the male penis A diploid cell formed in the male penis

Which of the following is a terrestrial biome? A. tundra B. benthic zone C. estuary

How do members of phylum annelida differ from other worm phyla?

Black lung disease was a common illness among coal miners in the 1950s, but it is almost unheard of in miners today. a. True b. False

Why don't absorptive surfaces of the small intestine get damaged by the acids from the stomach?

For any gene, when there are two alleles, and the frequency of one of the alleles is 0.5, then the frequency of the other one is:

Suppose a large number of dead fish are found floating in a lake. how would you determine whether they died from cultural eutrophication or from exposure to toxic chemicals?

Which best explains how gravity contributes to the formation of layers in protoplanets? Gravity attracts materials and causes compaction, which produces heat and leads to the melting, sinking, and rising of materials.

1. As an object moves towards another object the sound waves bunch up. True Or False 2. As an object moves toward another object the sound waves have lower frequency. True or False. 3.