Variety of Life Flashcards
(11 cards)
What is the basic structure of a protist cell?
Protists are mostly unicellular organisms. They have a nucleus, cytoplasm, and a cell membrane. Some, like Amoeba, have contractile vacuoles; others, like Paramecium, have cilia for movement.
What are the main features of fungal cells, and how do they compare to plant and animal cells
Fungi have a nucleus, cytoplasm, and a cell wall made of chitin (not cellulose like plants). They don’t have chloroplasts, unlike plants. Unlike animals, they can be multicellular (e.g., mushrooms) or unicellular (e.g., yeast).
Why can simple, unicellular organisms rely on diffusion for substance movement?
They have a large surface area to volume ratio, so diffusion is sufficient to move substances like oxygen and nutrients in and out of the cell efficiently.
How does respiration produce ATP in living organisms?
Glucose is broken down during respiration to release energy. This energy is used to convert ADP and phosphate into ATP, which cells use for energy-requiring processes.
What are the differences between aerobic and anaerobic respiration?
Aerobic: Uses oxygen, produces more ATP, releases carbon dioxide and water.
Anaerobic: Doesn’t use oxygen, produces less ATP, leads to lactic acid (in animals) or ethanol and CO₂ (in plants/yeast).
What is the word equation for anaerobic respiration in animals and plants?
Animals: Glucose → Lactic acid
Plants/Yeast: Glucose → Ethanol + Carbon dioxide
What role does yeast play in food production?
east ferments sugars anaerobically to produce carbon dioxide and ethanol. CO₂ causes bread to rise, while ethanol is used in brewing.
What factors can be investigated in a practical on anaerobic respiration in yeast?
Variables like sugar concentration, temperature, and presence/absence of oxygen can be tested by measuring CO₂ production (e.g., with gas syringes or limewater).
What role does Lactobacillus play in yoghurt production?
Lactobacillus bacteria ferment lactose (milk sugar) into lactic acid, which thickens the milk and gives yoghurt its sour taste.
What are the key conditions needed in an industrial fermenter?
Aseptic conditions: Prevent contamination.
Nutrients: For microorganism growth.
Optimum temp & pH: For enzyme activity.
Oxygenation: For aerobic microbes.
Agitation: Keeps conditions uniform and prevents clumping.
