What causes diffusion? i have a test to study for in biology and the only thing i dont get is what causes diffusion.?

Put the planets in order based on the length of time it takes them to orbit the Sun

What is the probability that a cross between a true-breeding pea plant with spherical seeds and a true-breeding pea plant with wrinkled seeds will produce f1 progeny with spherical seeds?

What can be concluded about a tropical storm as it moves away from the equator?

A population of 8,250 mice occupies the sand dunes in a coastal area. A severe hurricane washes out several miles of sand dunes. As a result, only 50 mice remain. The population has experienced A. horizontal gene transfer. B. gene flow. C.

Which of the subunits, when activated, associates with adenylyl cyclase (adenylate cyclase) and enables it to assume a more catalytically active conformation?

In muscle the source of a "phosphate molecule needed to recharge an adp molecule to an atp molecule" is

5. What would occur if ... a ... the wildflower population decreased?

Most crimes involve some evidence relating to the human body; for that reason, what related science is frequently used in forensic investigations? a) psychiatry b) physics c) botany d) biology

When evaluating your resources for authority, which of these question would you ask? A. Is the material too general, too technical, or just right for my needs? B. How recent is the information? C. Has this author been cited in other resources?

Which of these pairs is in Kingdom Fungi? A. mushrooms and bacteria B. diatoms and water molds C. mushrooms and yeast D. protist and virus