BIOL 1441 Lecture Final Exam, UTA Questions and Answers Latest Update 2025/2026
About 25 of the 92 natural elements are known to be essential to life. Which four of these 25
elements make up approximately 96% of living matter? - Answers carbon, hydrogen, nitrogen,
oxygen
Knowing just the atomic mass of an element allows inferences about which of the following? -
Answers the number of protons plus neutrons in the element
In what way are elements in the same column of the periodic table the same? - Answers They
have the same number of electrons in their valence shell.
Two atoms appear to have the same mass number. These atoms - Answers must have the
same number of protons + neutrons.
Nitrogen (N) is much more electronegative than hydrogen (H). Which of the following
statements is correct about the atoms in ammonia (NH3)?
A) Each hydrogen atom has a partial positive charge; the nitrogen atom has a partial negative
charge.
B) The nitrogen atom has a strong positive charge; each hydrogen atom has a strong positive
charge.
C) Each hydrogen atom has a slight negative charge; the nitrogen atom has a strong positive
charge.
D) The nitrogen atom has a slight positive charge; each hydrogen atom has a slight negative
charge.
E) There are covalent bonds between the hydrogen atoms and polar bonds between each
hydrogen atom and the nitrogen atom. - Answers A) Each hydrogen atom has a partial positive
charge; the nitrogen atom has a partial negative charge.
When two atoms are equally electronegative, they will interact to form - Answers nonpolar
covalent bonds.
What results from an unequal sharing of electrons between atoms? - Answers a polar covalent
bond
A covalent bond is likely to be polar when - Answers one of the atoms sharing electrons is much
more electronegative than the other atom.
Which type of bond must be broken for water to vaporize? - Answers hydrogen bonds
Temperature usually increases when water condenses. Which behavior of water is most directly
responsible for this phenomenon? - Answers the release of heat by the formation of hydrogen
, bonds
One liter of a solution of pH 2 has how many more hydrogen ions (H+) than 1 L of a solution of
pH 6? - Answers 10,000 times more
One liter of a solution of pH 9 has how many more hydroxyl ions (OH-) than 1 L of a solution of
pH 4? - Answers 100,000 times more
Buffers are substances that help resist shifts in pH by - Answers both donating H+ to a solution
when bases are added, and accepting H+ when acids are added.
One of the buffers that contribute to pH stability in human blood is carbonic acid (H2CO3).
Carbonic acid is a weak acid that dissociates into a bicarbonate ion (HCO3-) and a hydrogen ion
(H+). Thus,
H2CO3 ↔ HCO3- + H+
If the pH of the blood drops, one would expect - Answers the HCO3- to act as a base and
remove excess H+ with the formation of H2CO3.
The element present in all organic molecules is - Answers carbon.
Differences among organisms are caused by - Answers differences in the types and relative
amounts of organic molecules synthesized by each organism
Hermann Kolbe's synthesis of an organic compound, acetic acid, from inorganic substances
that had been prepared directly from pure elements was a significant milestone for what reason?
- Answers It proved that organic compounds could be synthesized from inorganic compounds
and disproved the concept of vitalism.
Large organic molecules are usually assembled by polymerization of a few kinds of simple
subunits. Which of the following is an exception to this statement? - Answers a steroid
Why are human sex hormones considered to be lipids? - Answers They are not soluble in water.
All of the following contain amino acids except
A) hemoglobin.
B) cholesterol.
C) antibodies.
D) enzymes.
About 25 of the 92 natural elements are known to be essential to life. Which four of these 25
elements make up approximately 96% of living matter? - Answers carbon, hydrogen, nitrogen,
oxygen
Knowing just the atomic mass of an element allows inferences about which of the following? -
Answers the number of protons plus neutrons in the element
In what way are elements in the same column of the periodic table the same? - Answers They
have the same number of electrons in their valence shell.
Two atoms appear to have the same mass number. These atoms - Answers must have the
same number of protons + neutrons.
Nitrogen (N) is much more electronegative than hydrogen (H). Which of the following
statements is correct about the atoms in ammonia (NH3)?
A) Each hydrogen atom has a partial positive charge; the nitrogen atom has a partial negative
charge.
B) The nitrogen atom has a strong positive charge; each hydrogen atom has a strong positive
charge.
C) Each hydrogen atom has a slight negative charge; the nitrogen atom has a strong positive
charge.
D) The nitrogen atom has a slight positive charge; each hydrogen atom has a slight negative
charge.
E) There are covalent bonds between the hydrogen atoms and polar bonds between each
hydrogen atom and the nitrogen atom. - Answers A) Each hydrogen atom has a partial positive
charge; the nitrogen atom has a partial negative charge.
When two atoms are equally electronegative, they will interact to form - Answers nonpolar
covalent bonds.
What results from an unequal sharing of electrons between atoms? - Answers a polar covalent
bond
A covalent bond is likely to be polar when - Answers one of the atoms sharing electrons is much
more electronegative than the other atom.
Which type of bond must be broken for water to vaporize? - Answers hydrogen bonds
Temperature usually increases when water condenses. Which behavior of water is most directly
responsible for this phenomenon? - Answers the release of heat by the formation of hydrogen
, bonds
One liter of a solution of pH 2 has how many more hydrogen ions (H+) than 1 L of a solution of
pH 6? - Answers 10,000 times more
One liter of a solution of pH 9 has how many more hydroxyl ions (OH-) than 1 L of a solution of
pH 4? - Answers 100,000 times more
Buffers are substances that help resist shifts in pH by - Answers both donating H+ to a solution
when bases are added, and accepting H+ when acids are added.
One of the buffers that contribute to pH stability in human blood is carbonic acid (H2CO3).
Carbonic acid is a weak acid that dissociates into a bicarbonate ion (HCO3-) and a hydrogen ion
(H+). Thus,
H2CO3 ↔ HCO3- + H+
If the pH of the blood drops, one would expect - Answers the HCO3- to act as a base and
remove excess H+ with the formation of H2CO3.
The element present in all organic molecules is - Answers carbon.
Differences among organisms are caused by - Answers differences in the types and relative
amounts of organic molecules synthesized by each organism
Hermann Kolbe's synthesis of an organic compound, acetic acid, from inorganic substances
that had been prepared directly from pure elements was a significant milestone for what reason?
- Answers It proved that organic compounds could be synthesized from inorganic compounds
and disproved the concept of vitalism.
Large organic molecules are usually assembled by polymerization of a few kinds of simple
subunits. Which of the following is an exception to this statement? - Answers a steroid
Why are human sex hormones considered to be lipids? - Answers They are not soluble in water.
All of the following contain amino acids except
A) hemoglobin.
B) cholesterol.
C) antibodies.
D) enzymes.
