What must be present for natural selection to occur?

Which part of the central nerves system causes you to move your body when hurt?

Why do developed countries have lower growth rates than less-developed countries? a.) lower death rates b.) higher birth rates c.) lower birth rates d.) higher death rates

Which statement best explains why Earth's outer core is in liquid form? The iron-nickel alloy melts due to hot temperatures. The outer core has a tarry consistency. This region is less dense when compared to the mantle.

What kind of factors are light, temperature, and soil composition? A. ecological B. biotic C. abiotic D. habitat

Human bone, muscle, and nerve ceils all contain the same number of chromosomes with the same complement of genes. What enables these cells to perform specialized activities?

When you look out the window, you can see constantly moving air. air is cycled in order to reach equilibrium. B) since these change the density of air and we know the air flows from the region of high density to the region of low density.

What effects do deforestation have on the animals?

Which best defines a diploid cell during meiosis? a cell that has double the number of chromosomes as the parent cell a cell that has half the number of chromosomes as the parent cell a cell that has double the number of chromosomes as the daughter

What is the best definitionof magnetosphere? a. a magnetosphere is a magnetic field around earth. b. a magnetosphere is the groups of atoms that are lined up inside a magnet. c.

True or false: tertiary sources can draw from, or summarize, a secondary source.