Questions and Answers of Cambridge International AS And A Level Biology

If methylene blue dye is added to a suspension of yeast cells, living cells do not take up the stain, and they remain colourless. However, dead cells are stained blue. This fact was used to carry out
The graph shows the progress of the digestion of starch by the enzyme salivary amylase. Why does the reaction slow down?A. End-product inhibition by maltose.B. The salivary amylase is becoming
In a reaction controlled by an enzyme, which of the following graphs shows the effect of substrate concentration on the rate of the reaction? A D B.
The diagram below shows an enzyme and two inhibitors of the enzyme, X and Y. Which of the following describes the two inhibitors?A. X and Y are competitive inhibitors.B. X and Y are non-competitive
a. Copy the following table to summarise some differences between collagen and haemoglobin.CollagenHaemoglobinUse the following to guide you.Row 1: State whether globular or fibrous.Row 2: State
Copy the diagrams below.a. Identify with labels which one represents a lipid and which a phospholipid.b. i For molecule A, indicate on the diagram where hydrolysis would take place if the molecule
a. The diagram below shows the structures of three amino acids.i. Draw a diagram to show the structure of the tripeptide with the following sequence: alanine–glycine–serine.ii. What is the
The diagram below shows a disaccharide called lactose. The carbon atoms are numbered. You are not expected to have seen this structure before. Lactose is a reducing sugar found in milk. It is made
State three characteristics of monosaccharides.
Copy and complete the table below, which summarises some of the functional categories into which proteins can be placed.CategoryExamplestructural1.2.enzymeinsulinhaemoglobin and
Copy and complete the following table. Place a tick or a cross in each box as appropriate. monomer polymer macromolecule polysaccharide contains subunits that form branched chains contains amino
Which diagram best represents the arrangement of water molecules around sodium (Na+) and chloride (Cl−) ions in solution? Nat Na Na Na+ A B D
What type of chemical reaction is involved in the formation of disulfide bonds?A. CondensationB. HydrolysisC. OxidationD. Reduction
Which term describes both collagen and haemoglobin?A. EnzymesB. Fibrous proteinsC. Globular proteinsD. Macromolecules
One technique used to investigate the activity of cell organelles is called differential centrifugation. In this technique, a tissue is homogenised (ground in a blender), placed in tubes and spun in
The electron micrograph on page 25 shows part of a secretory cell from the pancreas. The secretory vesicles are Golgi vesicles and appear as dark round structures. The magnification is × 8000.a.
Identify each cell structure or organelle from its description below.a. Manufactures lysosomesb. Manufactures ribosomesc. Site of protein synthesisd. Can bud off vesicles which form the Golgi bodye.
List:a. Three organelles each lacking a boundary membraneb. Three organelles each bounded by a single membranec. Three organelles each bounded by two membranes (an envelope)
Advice on answering question 6: If you are asked to distinguish between two things, it is likely that it is because they have certain things in common and that they may even be confused with each
List ten structures you could find in an electron micrograph of an animal cell which would be absent from the cell of a bacterium.
Copy and complete the following table, which compares light microscopes with electron microscopes. Some boxes have been filled in for you. Feature Light microscope Electron microscope source of
Which one of the following structures is found in animal cells, but not in plant cells?A. Cell surface membraneB. CentrioleC. ChloroplastD. Golgi body
The use of electrons as a source of radiation in the electron microscope allows high resolution to be achieved because electrons:A. Are negatively charged.B. Can be focused using electromagnets.C.
Which one of the following cell structures can be seen with a light microscope?A. MitochondrionB. RibosomeC. Rough ERD. Smooth ER

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