What created oxygen in the early atmosphere

Photosynthetic bacteria

Asteroids hitting the earth

plankton

Volcanic eruptions

forests

About how many years old is earth

The Seneca Falls Convention addressed the issue of A. women s rights. B. slavery in the Southern states. C. religious participation in schools. D. unequal education among children

What makes up the protein component of a nucleosome core? a. Histone H1 protein b. Two tetramers of histone proteins c. One tetramer of histone proteins d. Eight different histone proteins

Sound energy is transmitted through vibrations. a. True b. False

A "mystery molecule" was isolated in a laboratory and scientists found that the molecule readily crossed artificial membranes. Which of the following molecules can be ruled out as the "mystery molecule?"

Coal is used to produce energy. The harmful gases produced by coal are cleaned up by a method which needs a large amount of limestone. Predict and explain the long term effect on the environment of obtaining and using limestone.

True or false two genes may not segregate independently if they are on the same chromosmoe

Blood pressure rises and falls in a pattern corresponding to the phases of the

Immune system cells enter a resting phase after undergoing mitosis. when activated-for example, by an infection-they can reenter the sequence of events in the cell cycle that leads to cell division.

How does a muti-celluar organisms organise