Organisms must have variation within a population in order for natural selection to occur. Which situation is an example of this variation?

1. A frog living in a pond is eaten by a predator, while others in the same population survive.

2. A snake living in a desert produces more offspring than other snakes in the same population.

3. Some rabbits living in a forest have short, spotted ears, while others have long white ears.

4. Some birds living in a grassland eat less than other birds who eat the same food.

Read this summary of a scientific theory: "cells are the most basic structural and functional units of life. all living organisms are made up of one or more cells. all cells that are alive in the world today came from pre-existing cells." which of the following would require this theory to be modified? -a.) a survey finds that a majority of people believe viruses carry out the basic processes of life. -b.) a prominent scientist says she feels strongly that one day the theory will be challenged by life on other planets. -c.) the dna of unicellular and multi-cellular organisms is shown to have many fundamental similarities. -d.) scientific observations show that microscopic organisms living in the deep ocean are not made up of cells.