Which of the following sentences is the best example of a hypothesis

a. UV radiation does not cause skin cancer.

b. chickens lay more eggs when they are happy.

c. why does the earth orbit around the sun?

d. how many types of organisms are there?

Is a teaspoon of salt dissolving an example of chemical change?

The red lines represent dna. true the model shows the correct polarity between the orange and red strands. the 5' labels refer to the end of the strand with a nitrogenous base. the model correctly shows an arrowhead on the 3' ends of the strands.

All living things use nitrogen to A) reproduce. B) make sugar. C) make proteins. D) transport water.

The small flap of cartilage that folds over the windpipe when you swallow.

An organism that breaks down dead organisms and wastes

which of the following fossil is best described as forming when minerals replace all of the organisms

Why does a block of metal sink in water but the same size block of wood float? The molecules in the metal are closer together than the molecules of the wood. The metal is more compact.

Do eukaryotic have membrane-bound organelles?

Your chances of developing breast cancer dramatically increase with age. at what age do doctors recommend getting a yearly mammogram?

A mineral can be scratched by calcite but not by a fingernail. what is its approximate hardness?