BIOLOGY 181 EXAM SCRIPT 2025/2026 QUESTIONS AND
ANSWERS GRADED A+
✔✔Genes - ✔✔transmit information from parents to offspring
✔✔DNA - ✔✔double-stranded molecule that encodes genetic information
✔✔Nucleotides - ✔✔building blocks of DNA (A,T,C,G)
✔✔Genome - ✔✔entire library of genetic instructions that an organism inherits
✔✔Mitosis - ✔✔multicellular organisms undergo cellular division
✔✔Living things utilize energy - ✔✔ecosystems= living organisms+physical
environment provide energy; sun provides energy via photosynthesis
✔✔Enzymes - ✔✔special proteins that regulate chemical reactions
✔✔Homoeostasis - ✔✔maintain constant internal conditions(temperature,pH,moisture)
✔✔Archaea - ✔✔ancient bacteria/unicellular/live in extreme environments
✔✔Isotopes - ✔✔different forms of the same element that differ in # of neutrons and
atomic mass
✔✔protons - ✔✔positive
✔✔neutrons - ✔✔neutral
✔✔electrons - ✔✔negative
✔✔mass number - ✔✔neutrons + protons
✔✔atomic number - ✔✔positively charged protons in the nucleus
✔✔Electron shells - ✔✔electrons have different levels of energy depending on distance
Farther from nucleus= higher energy Closer to nucleus= lower energy
✔✔inner shell - ✔✔contains maximum of 2 electrons
✔✔valence - ✔✔maximum # of electrons - # of electrons in outermost shell/ Ex: sodium
(Na) 8(wants that max) -- 1(has)= needs 7e-
ANSWERS GRADED A+
✔✔Genes - ✔✔transmit information from parents to offspring
✔✔DNA - ✔✔double-stranded molecule that encodes genetic information
✔✔Nucleotides - ✔✔building blocks of DNA (A,T,C,G)
✔✔Genome - ✔✔entire library of genetic instructions that an organism inherits
✔✔Mitosis - ✔✔multicellular organisms undergo cellular division
✔✔Living things utilize energy - ✔✔ecosystems= living organisms+physical
environment provide energy; sun provides energy via photosynthesis
✔✔Enzymes - ✔✔special proteins that regulate chemical reactions
✔✔Homoeostasis - ✔✔maintain constant internal conditions(temperature,pH,moisture)
✔✔Archaea - ✔✔ancient bacteria/unicellular/live in extreme environments
✔✔Isotopes - ✔✔different forms of the same element that differ in # of neutrons and
atomic mass
✔✔protons - ✔✔positive
✔✔neutrons - ✔✔neutral
✔✔electrons - ✔✔negative
✔✔mass number - ✔✔neutrons + protons
✔✔atomic number - ✔✔positively charged protons in the nucleus
✔✔Electron shells - ✔✔electrons have different levels of energy depending on distance
Farther from nucleus= higher energy Closer to nucleus= lower energy
✔✔inner shell - ✔✔contains maximum of 2 electrons
✔✔valence - ✔✔maximum # of electrons - # of electrons in outermost shell/ Ex: sodium
(Na) 8(wants that max) -- 1(has)= needs 7e-
