Learning
1. Which of the following is a characteristic of all living organisms?
A) Movement
B) Cellular organization
C) Ability to grow indefinitely
D) Presence of a nucleus
Correct Answer: Cellular organization
Rationale: All living organisms are composed of one or more cells, which is
the fundamental characteristic distinguishing life from non-life. Movement is
not universal (e.g., plants do not move from place to place), growth is finite,
and prokaryotes lack a nucleus.
2. What is the primary function of the cell wall in a bacterial cell?
A) To store genetic material
B) To provide structural support and protection
C) To produce energy
D) To regulate the passage of substances
Correct Answer: To provide structural support and protection
Rationale: The cell wall is a rigid structure that surrounds the bacterial cell
membrane, providing structural support and protection against osmotic
pressure. It is not involved in energy production, genetic storage, or selective
permeability.
,3. In an experiment testing the effect of a new energy drink on heart rate,
the heart rate is measured. What is the role of the heart rate in this
experiment?
A) Independent variable
B) Dependent variable
C) Control variable
D) Constant variable
Correct Answer: Dependent variable
Rationale: The heart rate is the dependent variable because it is the factor
being measured and is expected to change in response to the independent
variable (the energy drink). The independent variable is what the
experimenter manipulates.
4. Atoms of the same element that have different numbers of neutrons are
called:
A) Ions
B) Isotopes
C) Molecules
D) Compounds
Correct Answer: Isotopes
Rationale: Isotopes are variants of a chemical element that have the same
number of protons but different numbers of neutrons. Ions have different
numbers of electrons, and molecules and compounds are combinations of
atoms.
5. Which subatomic particle has a negative charge?
, A) Proton
B) Neutron
C) Electron
D) Nucleus
Correct Answer: Electron
Rationale: Electrons are negatively charged subatomic particles that orbit the
nucleus. Protons carry a positive charge, and neutrons are neutral.
6. What is matter and what states can it exist in?
A) Matter is anything that has weight; exists as solid or liquid only
B) Matter is anything that takes up space and has mass; exists as solid,
liquid, or gas
C) Matter is anything that is visible; exists as solid only
D) Matter is anything that can be measured; exists as liquid or gas only
Correct Answer: Matter is anything that takes up space and has mass; exists
as solid, liquid, or gas
Rationale: Matter is anything that takes up space, by having volume, and has
mass. It can exist in a solid, liquid, or gaseous state.
7. Explain the difference between essential and trace elements.
A) Essential elements are found only in plants; trace elements are found only
in animals
B) Essential elements are required for human life; trace elements are only
required in small quantities