A tan or a sunburn is the result of exposure to ultraviolet light.

O True

O False

Only substances that are filtered by the kidneys can be excreted by them. a. true b. false

Neuroscientists, psychologists, and educators generally believe that teenagers need firm and consistent home and school environments that support learning and development.

The majority of Earth's atmosphere is nitrogen, N2. The percentage of nitrogen in Earth's atmosphere remains constant as prescribed by the law of conservation of matter and because it is a reasonably non-reactive gas.

A change in the nucleotide-base sequence of a gene or dna molecule is a

In a population of beetles, about 1 in every 6 beetles is slightly smaller and lighter in color than the others. the small, lighter beetles are a little better at evading predators and this increases the chances of survival and reproduction.

In the Bohr model of an atom, an electron's path is not known exactly.

How are mitosis and meiosis similar? a. they both have prophase and metaphase. b. they both produce gametes. c. they both produce tetrads. d. they both reduce the chromosome number?

Blank is between the times when a cell is dividing

Magnetometers revealed that the basalt rocks along the mid-ocean ridges are aligned in alternating, symmetrical patters.

A scientist wants to find the percent of teens that like the taste of "brand X"lemonade over "brand Y" lemonade. She conducts a taste test of 500 teenagers. She gives each teen a bottle of lemonade with the labels showing the brand of each lemonade.