A scientist is studying a field of sunflowers. Which of the following observations is an example of variation within this sunflower population?

All the sunflowers turn to face the sun during the day.

Some sunflowers naturally grow taller than others.

Bees visit the sunflowers to collect pollen.

The sunflowers require water to grow.

Which of the following groups of organisms best represents a population?

All the squirrels, birds, and insects in a single backyard.

All the gray squirrels living in Central Park.

A mother bear and her two cubs.

All the different species of trees in the Amazon rainforest.

All the different kinds of plants and animals living together in a forest.

A group of organisms of the same species that live in the same geographic area.

A single organism and all of its immediate offspring.

All the living things found on the entire planet Earth.

It ensures that all individuals are identical.

It allows the population to adapt to changing conditions.

It prevents the population from growing too large.

It guarantees that every individual will survive.