Which cell part controls the cell's activities and contains its DNA?
a) Mitochondria
b) Cell membrane
c) Ribosome
d) Nucleus
nucleus
Two pea plants that are both heterozygous for height (Tt) are crossed. T (tall) is dominant. What fraction of the offspring is expected to be short (tt)?
a) 0
b) 1/4
c) 1/2
d) 3/4
1/4
An element is a substance that…
a) can be separated into its parts by filtering.
b) cannot be broken down into simpler substances by chemical means.
c) is always a shiny metal.
d) is made of two or more different kinds of atoms.
cannot be broken down into simpler substances by chemical means
What does an alpha particle consist of?
a) One electron
b) One proton
c) A high-energy photon
d) Two protons and two neutrons
Two protons and two neutrons
Which of these is a renewable energy resource?
a) Coal
b) Solar energy
c) Natural gas
d) Uranium
Solar energy
Table salt (NaCl) dissolves in water but not in oil. What is the best explanation?
a) Oil is denser than water.
b) Water molecules are polar and attract the charged ions in salt.
c) Salt is a nonpolar compound.
d) Oil is colder than water.
Water molecules are polar and attract the charged ions in salt.
A wave travels through the same medium at a constant speed. If its frequency doubles, what happens to its wavelength?
a) It doubles.
b) It stays the same.
c) It becomes four times longer.
d) It is halved.
d) It is halved.
How does sedimentary rock form?
a) By compaction and cementation of sediments
b) By the cooling of magma
c) By heat and pressure deep underground
d) By the melting of existing rock
By compaction and cementation of sediments