Cells
This type of cell lacks a membrane-bound nucleus and organelles.
Prokaryote
Name the model used to describe the structure of the plasma membrane.
Fluid Mosaic Model
Name the FOUR phases of the eukaryotic cell cycle in order.
G1 → S → G2 → M (mitosis/cytokinesis)
Name the THREE systems covered in Unit 1 AOS 2.
Digestive, endocrine, and excretory
Define homeostasis.
Maintenance of a stable internal environment within a narrow range despite external/internal changes
Name TWO structures found in BOTH prokaryotic and eukaryotic cells.
Cell membrane, ribosomes, cytoplasm, DNA (any 2)
Name the TWO main components of the plasma membrane.
Phospholipid bilayer and proteins
During this phase of mitosis, sister chromatids are pulled to opposite poles.
Anaphase
This organ produces insulin and glucagon to regulate blood glucose.
Pancreas
Name THREE components of a stimulus-response model.
Stimulus, receptor, control centre, effector, response
This organelle is the site of ATP production via cellular respiration.
Mitochondria
This passive transport process moves water from high to low water concentration.
Osmosis
This form of cell division is used by prokaryotes to reproduce.
Binary fission
Name the functional unit of the kidney.
Nephron
Is blood glucose regulation an example of negative or positive feedback? Why?
Negative feedback — the response opposes the original stimulus to return to the set point
Explain why surface area to volume ratio limits cell size.
Volume increases faster than surface area — the membrane can't exchange materials fast enough
Explain the difference between facilitated diffusion and active transport.
Facilitated diffusion = passive, down concentration gradient, via proteins; Active transport = uses ATP, against concentration gradient
Define apoptosis and explain its role in the body.
Programmed cell death — eliminates damaged/unneeded cells; essential for development, immunity, and cancer prevention
Describe the role of the small intestine in digestion — name TWO structures that increase surface area.
Site of chemical digestion and nutrient absorption; villi and microvilli increase surface area
Describe the body's response to HIGH blood glucose — name the hormone and target organ.
Pancreas releases insulin → liver/muscle cells take up glucose → glycogenesis → blood glucose returns to normal
Compare prokaryotic and eukaryotic cells — name THREE structural differences.
No membrane-bound nucleus / no membrane-bound organelles / smaller ribosomes (70S vs 80S) / may have plasmids / no cytoskeleton
Describe the phospholipid bilayer and explain why it is selectively permeable.
Hydrophilic heads outward, hydrophobic tails inward; small nonpolar molecules pass freely, large/charged molecules need channel or carrier proteins
How can disruption to the cell cycle and malfunctions in apoptosis lead to cancer? Name TWO characteristics of cancer cells.
Mutations to control genes → unregulated division; apoptosis failure allows abnormal cells to survive. Cancer cells: uncontrolled division, metastasis, loss of contact inhibition, immortality
Distinguish between the endocrine and nervous systems in coordinating responses. Include speed and duration.
Endocrine: hormones via blood, slower + longer-lasting. Nervous: electrical impulses via neurons, faster + shorter-lived + more targeted
Compare homeostatic regulation of body temperature in response to both overheating AND overcooling.
Overheating: vasodilation, sweating, reduced metabolic rate. Overcooling: vasoconstriction, shivering, piloerection, increased metabolic rate — both via hypothalamus/negative feedback