Question 1
Which type of cell lacks a membrane-bound nucleus?
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Prokaryotic cell
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Eukaryotic cell
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Plant cell
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Animal cell
Question 2
In most bacterial cells, where is the main genetic material found?
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In the cytoplasm as a circular DNA loop
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In a nucleus as linear chromosomes
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In chloroplasts as circular DNA loops
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In mitochondria as circular DNA loops
Question 3
What are plasmids in bacteria?
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Small rings of extra DNA
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Membrane-bound organelles for respiration
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Protein-making organelles
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Large vacuoles full of cell sap
Question 4
What is the function of ribosomes?
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Protein synthesis
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Aerobic respiration
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Storage of cell sap
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Control of cell activities
Question 5
What does resolution mean in microscopy?
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Ability to distinguish two close points
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How large the image appears
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How thick the specimen is
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How bright the lamp is
Question 6
Which equation is used to calculate magnification?
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\(\text{magnification} = \frac{\text{image size}}{\text{real size}}\)
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\(\text{magnification} = \text{image size} \times \text{real size}\)
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\(\text{magnification} = \frac{\text{real size}}{\text{image size}}\)
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\(\text{magnification} = \text{real size} - \text{image size}\)
Question 7
A cell image is \(40\,\mathrm{mm}\) and the real cell is \(0.2\,\mathrm{mm}\). What is the magnification?
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\(200\times\)
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\(8\times\)
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\(20\times\)
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\(400\times\)
Question 8
A bacterium is \(5\,\mathrm{\mu m}\) long. What is this in millimetres?
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\(0.005\,\mathrm{mm}\)
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\(0.05\,\mathrm{mm}\)
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\(0.0005\,\mathrm{mm}\)
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\(5\,\mathrm{mm}\)
Question 9
What is a stem cell?
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An unspecialised cell able to divide and differentiate
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A specialised cell adapted for one function
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A reproductive cell with one chromosome set
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A cell formed when two gametes fuse
Question 10
Which cells can differentiate into many different cell types in early development?
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Embryonic stem cells
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Red blood cells
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Nerve cells
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Muscle fibres
Question 11
In plants, where are stem cells mainly found?
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Meristem tissue
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Xylem vessels
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Phloem vessels
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Guard cells
Question 12
Why is cell differentiation important in multicellular organisms?
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It produces cells specialised for different functions
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It gives each cell type a different genetic code
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It combines many cells into one larger cell
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It makes mature tissues stop using energy
Question 13
Which adaptation of a sperm cell helps it swim toward an egg?
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A flagellum
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A large permanent vacuole
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A cellulose cell wall
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Chloroplasts
Question 14
Which adaptation helps root hair cells absorb water and mineral ions?
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A long projection giving a large surface area
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A thick waxy layer reducing water loss
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Many chloroplasts absorbing light
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A large vacuole storing cell sap
Question 15
What is diffusion?
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Net movement of particles from high concentration to low concentration
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Movement of water through a partially permeable membrane
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Movement of particles from low concentration to high concentration using energy
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Random movement of whole cells in blood
Question 16
What is osmosis?
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Net movement of water through a partially permeable membrane from dilute to concentrated solution
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Net movement of solute particles from high to low concentration
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Movement of water from concentrated to dilute solution using energy
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Diffusion of oxygen into red blood cells
Question 17
Which process moves substances from low to high concentration using energy from respiration?
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Active transport
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Diffusion
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Osmosis
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Condensation
Question 18
Why can root hair cells take up mineral ions even when soil concentration is lower than inside the cell?
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They use active transport
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They use osmosis
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They use simple diffusion
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They use transpiration in the nucleus
Question 19
What usually happens to an animal cell in a very dilute solution?
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It gains water and may burst
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It loses water and shrinks
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It becomes turgid because of a cell wall
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It stops diffusion completely
Question 20
Why can an electron microscope show more detail than a light microscope?
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It has higher resolution
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It has lower magnification
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It always uses living specimens
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It does not need a vacuum
Question 21
Which two processes use mitosis in multicellular organisms?
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Growth and tissue repair
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Gamete production and fertilisation
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Digestion and absorption
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Respiration and excretion
Question 22
How many genetically identical daughter cells are made by mitosis?
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Two
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One
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Four
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Eight
Question 23
What is active transport?
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Movement against a concentration gradient using energy
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Movement down a concentration gradient without energy
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Water movement through a partially permeable membrane
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Particle movement carried by a flowing fluid
Question 24
Why can active transport be needed in the small intestine?
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To absorb glucose against its concentration gradient
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To move water down its water-potential gradient
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To move oxygen down its concentration gradient
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To digest starch into glucose
Question 25
What can uncontrolled division of transplanted stem cells cause?
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A tumour
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Tissue rejection
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Cell differentiation
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An immune memory response
Question 26
What is a pathogen culture used for in science?
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Studying microorganisms under controlled conditions
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Growing plant roots
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Measuring pulse rate
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Testing bone strength
Question 27
Why are inoculated agar plates sealed with tape?
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To reduce contamination and exposure to cultured microbes
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To prevent oxygen entering the plate
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To stop the agar supplying nutrients
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To raise the incubation temperature
Question 28
An image is \(40\,\mathrm{mm}\) wide; the cell is \(0.04\,\mathrm{mm}\). What is the magnification?
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\(1000\times\)
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\(10\times\)
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\(100\times\)
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\(10000\times\)
Question 29
Why are biological specimens often stained before viewing?
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To make structures easier to see
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To increase cell division
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To make cells produce more energy
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To remove the cell membrane
Question 30
How does a thin exchange surface increase diffusion rate?
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It shortens the diffusion distance
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It increases the surface temperature
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It supplies energy for active transport
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It raises the concentration on both sides