A phospholipid molecule has
1. a hydrophilic head that is repelled by water.
2. hydrophilic tails that are repelled by water.
3. a hydrophilic head that is attracted to water.
4. a hydrophobic head that is repelled by water.
5. hydrophobic tails that are attracted to water. - a hydrophilic head that is attracted to water.
A cell membrane is not
1. a fluid structure.
2. a rigid structure.
3. a mosaic structure.
4. a bilayered structure.
5. composed of phospholipid molecules. - a rigid structure
"The most restrictive taxon" and "the ability to breed only among themselves" reference
1. members of the same species.
2. members of the same domain.
3. members of the same genus.
4. members of the same family.
5. members of the same kingdom. - members of the same species.
A base
1. has a value of 7 on the pH scale.
2. is a chemical that adds hydrogen ions to a solution.
3. is a chemical that absorbs hydrogen ions from a solution.
,4. has a value below 7 on the pH scale. - is a chemical that absorbs hydrogen ions from a solution.
A cytoskeleton is
1. a structure that aids in the process of cell division.
2. found in the cytoplasm of eukaryotic cells.
3. a system of tracks used for intracellular transport.
4. composed of microtubules, microfilaments, and intermediate filaments.
5. All of these answers are correct. - all of these answers are correct
A eukaryotic cell
1. has a cell wall with peptidoglycan.
2. is usually smaller than a prokaryotic cell.
3. does not have membrane-bounded organelles.
4. has membrane-bounded organelles.
5. does not usually have a nucleus. - has membrane-bounded organelles.
A hydrogen bond
1. is a strong bond.
2. does not occur within a molecule.
3. may occur between molecules.
4. is not important to living cells.
5. usually has a hydrogen atom with a partial negative charge. - may occur between molecules
A major difference between bacteria and eukaryotes is that bacteria
1. have cell walls and eukaryotes do not.
2. do not have a nucleus in their cells and eukaryotes do.
3. have a nucleus in their cells and eukaryotes do not.
4. are autotrophs and eukaryotes are not.
, 5. do not have cell walls and eukaryotes do. - do not have a nucleus in their cells and eukaryotes
do.
A peptide bond is a(an)
1. ionic bond in proteins.
2. covalent bond in carbohydrates.
3. covalent bond in proteins.
4. ionic bond in carbohydrates. - covalent bond in proteins
A process by which cells break polymers down into smaller units is
1. hydrolysis.
2. dehydration synthesis.
3. reproduction.
4. All of these answers are correct. - hydrolysis
A process by which cells build large molecules from monomers is
1. hydrolysis.
2. reproduction.
3. dehydration synthesis.
4. All of these answers are correct. - dehydration synthesis
A prokaryotic cell
1. has a nucleus.
2. does not have a nucleus.
3. has a cell wall made of chitin.
4. is at least ten micrometers in diameter.
5. has membrane-bounded organelles. - does not have a nucleus