Cell Theory & Structure
Define the cell theory in one clear sentence.
All living things are made of cells; cells are the basic unit of life; all cells come from preexisting cells.
What is a factor that limits the number of organisms in an ecosystem called?
A limiting factor.
State Darwin’s basic idea that explains the origin of new species
Natural selection — differential survival and reproduction of organisms with advantageous traits leading to evolution.
Which macromolecule stores genetic information?
Nucleic Acids
The process where haploid gametes combine is called what?
Fertilization
Name the organelle that produces proteins and briefly state its role
Ribosome — synthesizes proteins by translating messenger RNA (mRNA) into polypeptide chains
When a population nears carrying capacity, resources become _______.
Limited or scarce — because the environment can support only a certain number of individuals, so resource availability per individual decreases, slowing population growth.
What modern cells resemble Earth’s first cells? Name the type and one reason scientists think so
Prokaryotes (archaea and bacteria) — they have simple cell structures without membrane-bound organelles and some live in conditions thought to resemble early Earth.
Which macromolecule forms the cell membrane?
Lipids
What is a karyotype and how does it help scientists study disorders?
A karyotype is a picture of an organism's chromosomes arranged by size and shape; it helps detect chromosomal abnormalities like extra or missing chromosomes
Which organelle is large in plant cells but small or often absent in animal cells?
Vacuole — stores water and nutrients and stores waste products.
Give one example of an abiotic factor and explain how it can affect an ecosystem.
Temperature — it affects metabolic rates, reproduction, and survival; extreme temperatures can limit which species live in an area.
Sunlight, Water, Soil, Oxygen, and Rocks are also acceptable with explanation.
Describe one event that could directly cause a disease to become a pandemic
Rapid global travel that easily spreads between humans. Example: a new respiratory virus that emerges and spreads internationally through air travel. COVID-19 is an example.
Name the macromolecule involved in nearly every bodily function
Proteins
Summarize the three stages of the cell cycle
Interphase (G1, S, G2) for growth and DNA replication, and the Mitotic (M) Phase for cell division (mitosis & cytokinesis)
Scientist who revolutionized ideas about eukaryotes (name) and one key reason their ideas mattered
Lynn Margulis — she proposed the endosymbiotic theory explaining how organelles like mitochondria and chloroplasts originated from free-living prokaryotes, changing ideas about eukaryote origins.
Aristotle’s classification philosophy and one way modern classification differs
Aristotle grouped organisms by observable traits (morphological similarities); modern classification uses evolutionary relationships (phylogeny) and genetic data to group organisms.
Explain Darwin’s “tree of life” analogy in one or two sentences
Darwin's analogy suggested that all species are related through common ancestry and branch over time, with each branch representing divergence into new species
Which macromolecule is NOT considered a polymer?
Lipids
Define apoptosis in one sentence and explain why it is important.
Apoptosis is programmed cell death; it removes damaged or unneeded cells and is essential for development and preventing harmful cell growth like cancer.
(Daily Double) Describe the general structure of a virus, including its genetic material and outer coating.
A virus typically consists of genetic material (either DNA or RNA) enclosed in a protein coat called a capsid; many viruses also have a lipid envelope with embedded proteins for attachment and entry into host cells.
List the eight taxa in the correct order from broadest to most specific
Domain, Kingdom, Phylum, Class, Order, Family, Genus, Species.
Identify what promoted belief in spontaneous generation historically, and name one experiment or scientist that helped disprove it.
Observations of life appearing around decaying matter promoted spontaneous generation; Louis Pasteur’s swan-neck flask experiments helped disprove spontaneous generation by showing that microorganisms come from other microorganisms, not spontaneously.
Give the reactants and products of photosynthesis (list both)
Reactants: carbon dioxide (CO2) and water (H2O) + light energy
Products: glucose (C6H12O6) and oxygen (O2)
What is the chromosome number in a haploid cell (in humans) and why is this important for sexual reproduction
The haploid number in humans is 23 chromosomes — this is important because when two haploid gametes fuse during fertilization, the diploid number 46 is restored, ensuring correct chromosome number in offspring.