When do scientists believe life originated on Earth?

A.

3 to 4 billion years ago

B.

600 million years ago

C.

less than 6,000 years ago

D.

over 5 billion years ago

Wich uses of iron are due to its chemical properties? Select two options

Moving molecules in and out of the cell is an important role of what?

What is a punnet square

These mighty birds are really rather interesting. What do you call an infant swan?

6. (3 pts) After transformation, 40 colonies were present on the plate. What is the transformation efficiency of the competent cells if 100 ng of DNA was used for transformation of 100 ul competent cells

Why might a water table drop

How did the 1898 discovery of blood types affect society?

Which of the following is a feeding source for fens? aquifers dexfoliants exfoliants nitrates

What system includes oceans, lakes, rivers, and groundwater? a. geosphere b. hydrosphere c. atmosphere d. biosphere

Fungal spores a. are only asexually produced. b. cannot be seen in a light microscope. c. are used to identify fungi. d. are produced by molds but not by yeasts. e. are only produced under harmful environmental conditions