Cell cycle.
Answers may include:
Binary fission occurs exclusively in prokaryotes, whereas Mitosis occurs in eukaryotes.
Which cell organelles is responsible for the digestion of old & worn out cells (once they've undergone Apoptosis) & are akin to 'rubbish collectors'?
Lysosomes.
Identify the name of the vessel in which sugars (i.e. glucose) are transported through the plant.
Phloem.
Large intestine/colon.
Outline the key differences between positive & negative feedback loops, & provide 1 example of each occurring within mammals.
In which phase of the eukaryotic cell cycle is the DNA replicated within the nucleus?
S phase (synthesis phase).
What are the structures of flattened discs (thylakoids) found within chloroplasts called?
Identify an example of a source & a sink within a vascular plant.
Source: leaves.
Sink: fruit/flower/roots.
Explain the key differences between chemical & mechanical digestion, with examples of where in the digestive system each type occurs & which structures are involved.
Mechanical digestion refers to the physical breakdown of food, which occurs in the mouth (via the teeth) & stomach (via the churning of the stomach).
Chemical digestion refers to the breakdown of food with chemicals, which occurs in the mouth (via saliva), stomach (via Hydrochloric acid) & small intestine (via the absorption of nutrients into the bloodstream).Death occurs at 44 degrees or higher, & 32 degrees or below.
Answer should include:
Optimal range (middle portion of graph) 36.5 - 37.5.
Zone of physiological stress: 35 - 36.5 degrees & 37.5 - 43 degrees.
Zone of intolerance: 44 degrees or greater & 32 degrees or less.
How is Telophase different to Cytokinesis?
Answer may include:
Telophase sees the cell developing a cleavage furrow, whereas Cytokinesis refers to the cell splitting in two.
List 3 key structural differences seen in plant & animal cells & explain their significance.
Answers may include:
Presence of a cell wall in plant cells - provides structure to the plant & helps to resist cell lysis.
Plant cells contain a large central vacuole, which maintains turgor pressure within the cell.
Plant cells contain chloroplasts, which are responsible for carrying out the process of photosynthesis.
Explain why the (woody) xylem tissue in vascular plants is dead, whilst the phloem tissue is alive in terms of the roles of each vessel.
The movement of water throughout xylem vessels is unidirectional (from the roots towards the leaves), whilst the phloem vessels moves sugars (i.e. glucose) in both directions.
Distinguish between endocrine & exocrine glands within the mammalian endocrine system & provide an example of each.
Endocrine glands are ductless, meaning they have no tubes/ducts for hormones to be released into.
E.g. pancreas, adrenal glands, etc.
Exocrine glands have ducts/tubes for hormones/chemical to travel through.
E.g. tear ducts, sweat glands, etc.
Create a stimulus-response model for a hiker who became stranded in the Tasmanian wilderness during Winter.
Stimulus-response model should include:
Stimulus (decrease in body temperature), Receptor (hypothalamus), Control centre (hypothalamus), Effector (skeletal muscles, which start to contract involuntarily) & Response (body temperature increases, due to shivering).
List a key difference between Apoptosis & Necrosis, & provide an example of each within the human body.
Answers may include:
Apoptosis refers to the programmed, orderly death of a cell (e.g. diseased, old or worn out cells), whereas Necrosis occurs in a much more reactionary & 'messy' way, often due to cell injury (e.g. frostbite in the fingers & toes).
What is the name for the tail commonly seen on prokaryotic cells which enable them to move? What's the only eukaryotic cell type which also contains this tail?
What are the 2 cells surrounding a stoma on a plant leaf & in what circumstances are they turgid & flaccid?
Guard cells.
When water is plentiful, the guard cells will be turgid & the stoma open.
When water is scarce, the guard cells will be flaccid & the stoma closed.
Identify the name of the structural unit of the kidney which filters the blood & list the name of the ball of capillaries & the capsule which contains this ball of capillaries.
Structural units of the kidney: Nephron.
Ball of capillaries: Glomerulus.
Capsule which contains the ball of capillaries: Bowman's capsule.
Distinguish between the terms glucose, glycogen & glucagon, with regard to blood glucose regulation in humans, & outline the role of each within the body.
Glucose: a type of simple sugar, which acts as a fuel source for the body's cells.
Glycogen: the stored form of glucose, which is typically found in the liver & skeletal muscles for later use when glucose supplies are scarce.
Glucagon: a hormone which is released when low glucose levels are detected, which signals glycogen to be broken down into glucose for use by the body's cells.
List each potency of stem cell in order from most specific to least specific & specify where it originates from/is found within the human body.
Multipotent, Pluripotent & Totipotent (listed in the order of most to least specific).
Multipotent stem cells: bone marrow & brain tissue.
Pluripotent stem cells: inner cell mass of blastocyst.
Totipotent stem cells: fertilised egg.
The ER is involved in the transport of molecules around the cell, whilst the Golgi body is involved in the processing & packaging of molecules.
The ER can have ribosomes attached to it (rough ER), whilst the Golgi body doesn't.
List the 3 factors which affect the rate of transpiration in vascular plants & briefly explain how each factor affects transpiration rates.
Humidity - as humidity (water vapour in the air) increases, transpiration decreases.
Temperature - as temperature increases, transpiration also increases.
Wind - stronger winds result in increased rates of transpiration.
List the order of structures within the nephron which the filtrate (soon-to-be urine) passes through en route to the bladder, starting from the glomerulus.
Identify & provide an example of each of the 4 mechanisms of thermoregulation in mammals.
Conduction: e.g. a snake warming up by sunning itself on a rock.
Convection: a wind blowing across wet skin, rapidly cooling the organism.
Radiation: a black bear warming up faster than a polar bear, due to the increase in heat absorption from darker colours.
Evaporation: humans cooling down by sweating in hot conditions.