Cell Types
What is the name given to cells that do not contain a nucleus?
Prokaryotic cells
Which organelle is the site of aerobic cellular respiration?
Mitochondrion
What is the movement of water across a selectively permeable membrane called?
Osmosis
What process produces two genetically identical daughter cells?
Mitosis
What is a stem cell?
An undifferentiated cell that can self-renew and differentiate
What feature is present in eukaryotic cells but absent in prokaryotic cells?
A membrane-bound nucleus
Which organelle modifies and packages proteins before secretion?
Golgi apparatus
What type of transport requires no energy and moves substances down a concentration gradient?
Passive transport
During which phase of mitosis do chromosomes align along the equator?
Metaphase
What term describes a stem cell's ability to develop into specialised cells?
Differentiation
A cell contains circular DNA and no membrane-bound organelles. What type of organism most likely possesses this cell?
A bacterium (prokaryote)
Why do muscle cells typically contain more mitochondria than fat cells?
They require more ATP for contraction
A red blood cell swells and bursts when placed in pure water. Explain why.
Water enters the cell by osmosis because the surrounding solution is hypotonic
Why must DNA replicate before mitosis occurs?
So each daughter cell receives a complete set of genetic information
Why are embryonic stem cells considered more useful than adult stem cells for regenerative medicine?
They can differentiate into a wider range of cell types
Mitochondria contain their own DNA and ribosomes. How does this support the endosymbiotic theory?
It suggests mitochondria evolved from ancient bacteria that were engulfed by larger cells
A toxin damages a cell's ribosomes. Predict the immediate effect on the cell.
Protein synthesis would decrease or stop
An animal cell is placed in a hypertonic solution. Describe what happens to the cell and explain why.
Water leaves the cell by osmosis and the cell shrinks
Explain one advantage of apoptosis to a multicellular organism.
It removes damaged or potentially harmful cells before they can cause problems
Why are induced pluripotent stem cells (iPSCs) often considered less ethically controversial than embryonic stem cells?
No embryos are destroyed to obtain them
A scientist discovers a cell containing a nucleus, cell wall and chloroplasts. Explain how these observations allow the cell to be classified.
It is a plant eukaryotic cell because it contains membrane-bound organelles and plant-specific structures
A cell produces large amounts of digestive enzymes for secretion. Which organelles would be especially abundant and why?
Rough ER and Golgi apparatus because proteins must be synthesised, modified and packaged for export
A membrane protein responsible for facilitated diffusion becomes non-functional. Predict the effect on glucose transport across the membrane.
Glucose uptake would decrease because it can no longer efficiently move through membrane transport proteins
A mutation prevents cells from undergoing apoptosis. Explain how this may contribute to cancer.
Damaged cells continue surviving and dividing, increasing the risk of tumour formation
A patient receives stem cells derived from their own skin cells. Explain one advantage and one limitation of this treatment.
Advantage: reduced immune rejection. Limitation: reprogramming may introduce mutations or be inefficient