All of the following were likely present on the early Earth during the evolution of self-replicating molecules except

amino acids

nucleotides

lipids

free oxygen

What is vegetative propagation

We can represent atoms by listing the number of protons, neutrons, and electrons - for example 2P+, 2no, 2e - for helium. Which of the following represents the 18O isotope of oxygen? a. 7P+, 2no, 9e- b. 8P+, 10no, 8e- c. 9P+, 9no, 9e- d.

What happens to water once it reaches Earth's surface

Explain why it is important that scientists only test one independent variable at a time in an experiment.

What is the trait and what are the physical characteristics of hair?

A) What are the bases of mRNA coded for by this section of DNA before the mutation? Hint in RNA A pairs with U.

How does secondary succession differ from primary succession? It begins where no plants have grown. It begins on bare rock or land. Soil nutrients are already in place. Lichens and mosses form soil first.

True of False? The structure of the cell membrane is what allows water and other molecules to move in and out of cells.

Dolphins and fish have similar body shapes. isthis feature more likely a homologous or analogoustrait?

Which of the following is not a phase of gastric secretion? A. cephalic B. gastric C. intestinal D. enterogastric