Which cell structure is referred to as the gatekeeper because it directs substances to move into and out of the cell? a cell wall b nucleus c vacuole d cell membrane?

What is ethical controversy over using human embryonic stem cells for research

Temperate rainforests are always located near the equator

49. When materials move in and out of a cell correctly and the cell functions to its ability this is called a qualitative c. adaptation b. binomial nomenclature d. homeostasis

Which are protostomes? A. Worms B. Horses C. Flowering plants D. Humans

Bottom trawling is a destructive fishing practice that destroys ocean habitats. true or false?

Which statements are true of heterogeneous mixtures? 1) they settle out. 2) the proportions of solute to solvent may vary. 3) the solute is evenly distributed throughout. 4) they are composed of two solvents and two solutes. a. 1 and 2 b. 2 and 4 c.

Why do plants not need heterotrophs

During development, individual cells of the same organism begin to produce different proteins because A) not all cells can synthesize proteins. B) specific genes are activated in the cells. C) the cells have different numbers of chromosomes.

Most scientists believe earth's early archean atmosphere was formed primarily by gases released from:

Choose the words to finish the sentence A strand of DNA is a polymer of Choose ... joins by covalent bonds between the Choose ... of one monomer and the Choose ... of the next monomer A strand ...