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Rationales 2025|2026 Q&A | Instant
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1. Which property of life allows organisms to maintain a relatively stable
internal environment?
a) Evolution
b) Metabolism
c) Growth
d) Homeostasis
Rationale: Homeostasis is the process by which organisms regulate
their internal conditions despite external changes.
2. Which of the following is the smallest unit of life?
a) Tissue
, b) Organ
c) Cell
d) Molecule
Rationale: The cell is the basic unit of structure and function in living
organisms.
3. Which of the following is NOT a domain of life?
a) Archaea
b) Bacteria
c) Protista
d) Eukarya
Rationale: Protista is a kingdom within Eukarya, not a domain. The
three domains are Bacteria, Archaea, and Eukarya.
4. The atomic number of an element is determined by the number of:
a) Neutrons
b) Electrons
c) Protons
d) Isotopes
Rationale: The atomic number corresponds to the number of protons
in an atom’s nucleus.
5. Which bond involves the sharing of electron pairs between atoms?
a) Ionic bond
b) Hydrogen bond
c) Covalent bond
, d) Van der Waals forces
Rationale: Covalent bonds are formed when atoms share electrons to
achieve stability.
6. Water’s high heat capacity is due to:
a) Ionic bonding
b) Nonpolar covalent bonding
c) Hydrogen bonding
d) Hydrophobic interactions
Rationale: Hydrogen bonds between water molecules allow water to
absorb and retain heat.
7. Which type of macromolecule is primarily responsible for storing
genetic information?
a) Carbohydrates
b) Proteins
c) Lipids
d) Nucleic acids
Rationale: DNA and RNA are nucleic acids that encode genetic
information.
8. The monomers of proteins are:
a) Nucleotides
b) Amino acids
c) Monosaccharides
, d) Fatty acids
Rationale: Proteins are polymers made of amino acid monomers.
9. The primary structure of a protein refers to:
a) Alpha helices and beta sheets
b) The 3D folded shape
c) Multiple polypeptide chains
d) The sequence of amino acids
Rationale: Primary structure is the linear sequence of amino acids in
a polypeptide.
10. Which organelle is known as the powerhouse of the cell?
a) Chloroplast
b) Ribosome
c) Mitochondrion
d) Golgi apparatus
Rationale: Mitochondria generate ATP through cellular respiration.
11. Which of the following is found in plant cells but not in animal
cells?
a) Ribosomes
b) Chloroplasts
c) Mitochondria
d) Endoplasmic reticulum
Rationale: Chloroplasts carry out photosynthesis and are unique to
plants and some protists.