In biological systems, the catalyst for a chemical reaction is usually proteins called

What must happen before meiosis can begin?

Dandruff is caused by the shedding of excess cells from the outer layer of the skin

Which of the following is incorrectly matched with its description? a. Carrier Protein: binds specifically to molecules it assists Ion b. Channel: allows passage of ions c. Osmosis: diffusion of water d.

The most diverse and prevalent organisms on earth are? a. insects b. vertebrates c. mammals d. bacteria

Sperm are created through meiosis in an area of the testes called the seminiferous tubules. Through which structure do the sperm travel to exit the testes?

Which of the following is a biotic factor? a. Parasites b. Sun c. Soil d. Temperature

When nucleotide sequence of the cell's DNA becomes altered it causes what

Factors that can alter the level of expression of a gene include Check All That Apply an increase in l temperature. an increase in salinity. exposure to UV radiation. presence of particular energy substrate.

What did Virchow observe that led him to determine one of the main components of cell theory?

Discuss the social and biological construction of race in the United states.