UTSA BIO 1404 Biosciences I Midterm Exam (Units 1-7) -
Questions with Correct Answers (Verified Update)
50 questions
1. Which subatomic particle determines how an atom bonds with other atoms?
A. Neutrons
B. Protons in the nucleus
C. The nucleus as a whole
D. Valence electrons
Correct Answer: D. Valence electrons
Rationale: Bonding depends on electrons in the outermost shell.
2. Sodium (Na) gives an electron to chlorine (Cl). The resulting attraction is a(n):
A. Hydrogen bond
B. Nonpolar covalent bond
C. Ionic bond
D. Peptide bond
Correct Answer: C. Ionic bond
Rationale: Na+ and Cl- are held together by electrostatic attraction.
3. Coastal cities have milder climates than inland cities mainly because of water's:
A. Low cohesion
B. High specific heat
C. Ability to ionize
D. Nonpolar nature
Correct Answer: B. High specific heat
Rationale: Oceans absorb and release heat slowly, moderating nearby temperatures.
4. Oil and water do not mix because oil molecules are:
A. Charged
B. Nonpolar and cannot hydrogen-bond with water
C. Polar
D. Made of ions
Correct Answer: B. Nonpolar and cannot hydrogen-bond with water
Rationale: Hydrophobic molecules are excluded as water molecules hydrogen-bond with each other.
5. Which functional group is found in ATP and DNA and gives them a negative charge?
A. Phosphate group
B. Methyl group
C. Hydroxyl group
D. Sulfhydryl group
Correct Answer: A. Phosphate group
Rationale: Phosphate groups ionize to carry negative charges.
6. Ocean acidification occurs as seawater absorbs CO2. The pH of seawater therefore:
A. Increases
B. Stays exactly 7
C. Decreases
D. Becomes basic
Correct Answer: C. Decreases
Rationale: CO2 forms carbonic acid, which releases H+ and lowers pH, harming shell-forming organisms.
, 7. A molecule with the formula C6H12O6 is most likely a:
A. Fatty acid
B. Amino acid
C. Monosaccharide
D. Nucleotide
Correct Answer: C. Monosaccharide
Rationale: Carbohydrates follow roughly a (CH2O)n ratio; glucose is C6H12O6.
8. Which polysaccharide is used by plants for energy storage?
A. Cellulose
B. Chitin
C. Glycogen
D. Starch
Correct Answer: D. Starch
Rationale: Plants store glucose as starch (amylose and amylopectin).
9. Why do fats store more energy per gram than carbohydrates?
A. They have more C-H bonds and fewer oxygen atoms
B. They are polymers of glucose
C. They contain nitrogen
D. They dissolve in water
Correct Answer: A. They have more C-H bonds and fewer oxygen atoms
Rationale: Fats are more reduced, releasing about 9 kcal/g vs. about 4 kcal/g for carbohydrates.
10. Hydrophobic interactions among R groups that cluster away from water mainly contribute to
a protein's:
A. Primary structure
B. Peptide bonds
C. Tertiary structure
D. Quaternary structure only
Correct Answer: C. Tertiary structure
Rationale: R-group interactions (hydrophobic, ionic, hydrogen, disulfide) fold the protein in 3D.
11. Molecular chaperones help proteins:
A. Form peptide bonds
B. Fold correctly
C. Be transcribed
D. Leave the nucleus
Correct Answer: B. Fold correctly
Rationale: Chaperonins provide a protected environment for proper folding.
12. Which pair is correctly matched?
A. Nucleic acid - stores hereditary information
B. Lipid - enzyme catalysis
C. Carbohydrate - genetic code
D. Protein - long-term energy storage only
Correct Answer: A. Nucleic acid - stores hereditary information
Rationale: DNA and RNA store and transmit genetic information.
Questions with Correct Answers (Verified Update)
50 questions
1. Which subatomic particle determines how an atom bonds with other atoms?
A. Neutrons
B. Protons in the nucleus
C. The nucleus as a whole
D. Valence electrons
Correct Answer: D. Valence electrons
Rationale: Bonding depends on electrons in the outermost shell.
2. Sodium (Na) gives an electron to chlorine (Cl). The resulting attraction is a(n):
A. Hydrogen bond
B. Nonpolar covalent bond
C. Ionic bond
D. Peptide bond
Correct Answer: C. Ionic bond
Rationale: Na+ and Cl- are held together by electrostatic attraction.
3. Coastal cities have milder climates than inland cities mainly because of water's:
A. Low cohesion
B. High specific heat
C. Ability to ionize
D. Nonpolar nature
Correct Answer: B. High specific heat
Rationale: Oceans absorb and release heat slowly, moderating nearby temperatures.
4. Oil and water do not mix because oil molecules are:
A. Charged
B. Nonpolar and cannot hydrogen-bond with water
C. Polar
D. Made of ions
Correct Answer: B. Nonpolar and cannot hydrogen-bond with water
Rationale: Hydrophobic molecules are excluded as water molecules hydrogen-bond with each other.
5. Which functional group is found in ATP and DNA and gives them a negative charge?
A. Phosphate group
B. Methyl group
C. Hydroxyl group
D. Sulfhydryl group
Correct Answer: A. Phosphate group
Rationale: Phosphate groups ionize to carry negative charges.
6. Ocean acidification occurs as seawater absorbs CO2. The pH of seawater therefore:
A. Increases
B. Stays exactly 7
C. Decreases
D. Becomes basic
Correct Answer: C. Decreases
Rationale: CO2 forms carbonic acid, which releases H+ and lowers pH, harming shell-forming organisms.
, 7. A molecule with the formula C6H12O6 is most likely a:
A. Fatty acid
B. Amino acid
C. Monosaccharide
D. Nucleotide
Correct Answer: C. Monosaccharide
Rationale: Carbohydrates follow roughly a (CH2O)n ratio; glucose is C6H12O6.
8. Which polysaccharide is used by plants for energy storage?
A. Cellulose
B. Chitin
C. Glycogen
D. Starch
Correct Answer: D. Starch
Rationale: Plants store glucose as starch (amylose and amylopectin).
9. Why do fats store more energy per gram than carbohydrates?
A. They have more C-H bonds and fewer oxygen atoms
B. They are polymers of glucose
C. They contain nitrogen
D. They dissolve in water
Correct Answer: A. They have more C-H bonds and fewer oxygen atoms
Rationale: Fats are more reduced, releasing about 9 kcal/g vs. about 4 kcal/g for carbohydrates.
10. Hydrophobic interactions among R groups that cluster away from water mainly contribute to
a protein's:
A. Primary structure
B. Peptide bonds
C. Tertiary structure
D. Quaternary structure only
Correct Answer: C. Tertiary structure
Rationale: R-group interactions (hydrophobic, ionic, hydrogen, disulfide) fold the protein in 3D.
11. Molecular chaperones help proteins:
A. Form peptide bonds
B. Fold correctly
C. Be transcribed
D. Leave the nucleus
Correct Answer: B. Fold correctly
Rationale: Chaperonins provide a protected environment for proper folding.
12. Which pair is correctly matched?
A. Nucleic acid - stores hereditary information
B. Lipid - enzyme catalysis
C. Carbohydrate - genetic code
D. Protein - long-term energy storage only
Correct Answer: A. Nucleic acid - stores hereditary information
Rationale: DNA and RNA store and transmit genetic information.
