Cell Structure & Microorganisms
This organelle controls the activities of a cell.
What is the nucleus?
This is the net movement of particles from a high concentration to a low concentration.
What is diffusion?
This reagent is used to test for proteins.
What is Biruet solution?
This variable is deliberately changed during an investigation.
What is the independent variable?
This is the unit commonly used to measure the size of cells.
What is a micrometre (μm)?
This organelle is the site of aerobic respiration.
What is the mitochondrion?
This is the movement of water through a partially permeable membrane from a dilute solution to a concentrated solution.
What is osmosis?
This colour indicates a positive Benedict's test for a high concentration of glucose.
What is brick-red?
This variable is measured during an investigation.
What is the dependent variable?
This equation is used to calculate magnification.
What is image size ÷ actual size?
This group of microorganisms includes Amoeba and Euglena.
What are protoctists/protists/protoctista?
This process requires energy from respiration to move substances against a concentration gradient.
What is active transport?
These biological molecules act as catalysts in living organisms.
What are enzymes?
This piece of equipment would safely keep Benedict's solution at 70°C during a food test.
What is a water bath?
A cell measures 8 mm on an image and is actually 40 μm long. This is the magnification.
What is 200×?
These are three structural features found in bacteria but not viruses.
What are cytoplasm, cell membrane and ribosomes?
Allow: Cell wall, flagella, plasmid, nucleoid
This would happen to a red blood cell placed in distilled water.
What is it would swells and bursts (osmolysis)?
This is how a saprotrophic fungus obtains nutrients from food.
What is extracellular digestion followed by absorption of soluble products?
This is why scientists have to dry potato cylinders dry before measuring mass.
What is "because water on the outside of the potato affects the mass measurement"?
This type of microscope uses electrons rather than light and produces images with much higher resolution.
What is an electron microscope?
This is why viruses are not considered living organisms despite being able to reproduce.
What is that they cannot reproduce independently (and have no cellular structure or metabolism)?
A potato cylinder gains no mass when placed in a 0.50 mol dm⁻³ sugar solution. This suggests the concentration inside the potato cells is...
What is approximately 0.50 mol dm⁻³?
This explains why mould growth was reduced when pickles are stored in the fridge.
What is that the cold conditions reduces kinetic energy in fungal enzymes and inhibits growth?
A student only used one potato cylinder for each concentration in an osmosis investigation. This affects the investigation because...
What is the reliability is reduced because anomalous results cannot be identified?
A ribosome appears 18 mm wide in an electron micrograph. The actual diameter of the ribosome is 30 nm. This is the magnification of the image.
Answer: What is 600,000×?
(Working: 18 mm = 18,000,000 nm; 18,000,000 ÷ 30 = 600,000)