Cell Theory & Structure 🧬
State the 3 parts of the cell theory.
All living things are made of 1+ cells; Cells are the basic unit of life; All cells come from pre-existing cells
Which organelle is known as the “powerhouse” of the cell?
Mitochondria → ATP production
What is the purpose of mitosis?
Growth, repair, and maintenance → makes 2 identical diploid cells
What is the main function of the digestive system?
Breaks down food + absorbs nutrients into blood
A lung disease where airways narrow and inflame
Asthma
What is the difference between prokaryotes and eukaryotes?
Prokaryotes = simple, no nucleus, bacteria/archaea; Eukaryotes = complex, nucleus + organelles
What organelle is the “master chef,” building proteins?
Ribosomes
What stage of mitosis do chromosomes line up at the equator?
Metaphase
Where in the respiratory system does gas exchange occur?
Alveoli
A disease where alveoli break down, often from smoking
Emphysema
Why do specialized cells (like muscle vs skin) look different even though they all contain the same DNA
Different genes are expressed, which means even though they have the same DNA, they will have vastly different functions and appearances
What is the function of the Golgi apparatus?
Modifies, packages, and ships proteins in vesicles
A body cell has 46 chromosomes. After mitosis, how many chromosomes will each daughter cell have?
After mitosis → 46 chromosomes (identical diploid cells).
Trace the path of oxygen from the nose to a muscle cell.
Nose → trachea → bronchi → bronchioles → alveoli → capillaries → circulatory system → muscle cell
A circulatory disease where blood pressure is chronically high
Hypertension
Which 3 organelles are present in plant cells but not animal cells?
Cell wall, chloroplasts, large central vacuole
What is apoptosis, and which organelle helps trigger it?
Programmed cell death; mitochondria release signals → lysosomes break down the cell
What is a stem cell? Why are embryonic stem cells so valuable?
Undifferentiated cell that can become many cell types; embryonic stem cells = totipotent/pluripotent → can become almost any cell
What’s the difference between arteries and veins?
Arteries = away from heart (thicker walls), Veins = toward heart (valves to prevent backflow)
A genetic blood disorder where red blood cells are crescent-shaped
Sickle Cell Anemia
Why are membranes described as “semi-permeable”? Give an example of what passes freely vs what needs help
Some substances can diffuse freely, e.g. gases; others need transport proteins/gates
Explain how rough ER and ribosomes work together to make proteins for export
Ribosomes on RER synthesize proteins → fed into RER → packaged/transported in vesicles
What happens during the S phase of the cell cycle, and why is it important?
DNA replication → ensures each daughter cell gets a full genome
Explain how digestive, respiratory, and circulatory systems work together to make ATP.
Digestive supplies glucose → respiratory supplies O₂ → circulatory delivers both → mitochondria use them in cellular respiration → ATP
Explain one way lifestyle, genetics, and environment each contribute to cancer risk.
Lifestyle = smoking, poor diet; Genetics = inherited mutations; Environment = UV, asbestos, HPV