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Topic 1
Topic 2
Topic 3
Topic 4
Topic 5
100
This is the loss of electrons
What is oxidation
100
A community and its abiotic environment
What is ecosystem
100
Thylakoid membranes form stacks of this
What is grana
100
This is the gain of electrons
What is reduction
100
A group of organisms of the same species that live in the same area at the same time
What is population
200
The passive movement of water molecules across a partially permeable membrane from a region of lower solute concentration to a region of higher solute concentration
What is osmosis
200
Acetyl Co-A is produced from pyruvate by...
What is oxidation and decarboxylation
200
The main molecules forming membranes
What is phospholipids and proteins
200
Examples of monosaccharide, disaccharide, polysaccharide
What is galactose, maltose, and glycogen
200
The number of carbon atoms in glycerol
What is 3
300
Define aerobic respiration
What is the conversion of pyruvate to carbon dioxide and water yields a large amount of ATP
300
The source of oxygen released during photosynthesis
What is water
300
A change in the base sequence of DNA
What is gene mutation
300
Non-disjunction occurs as a result of...
What is a failure in the spindle fibre network of mircotubules
300
The specific region of an enzyme to which the substrate or substrates bind
What is active site
400
A mother of a child is blood group A and the father is blood group B. The child could have blood type(s)...
What is A, B, AB, or O
400
The passive movement of a substance from a region of high concentration to a region of low concentration.
What is diffusion
400
Difference between the cyclic and non-cyclic pathways
What is with non-cyclic the electrons continue on to end in the NADP+ whereas with cyclic they are returned to he chlorophyll in photosystem I
400
Define absorption spectrum
What is representation of how much of particular wavelength is absorbed by the chloroplast pigments
400
Define recombination
What is the appearance amongst the offspring of combinations of characteristics not found in the parents
500
Describe enzyme activity using the lock and key model
What is enzymes are large protein molecules folded in such a way as to have a special region called the active site. The shape of the active site is unique for each enzyme as it corresponds to the shape of the substrate that fits in it. In a mixture of substrate and enzyme amylase which acts on starch to break it down into maltose. Amylase will only act on starch has the right shape to fit into the active site of amylase. Maltose can be broken down further into two glucose molecules, but this requires a different enzyme
500
Outline the events in meiosis that reduce the number of chromosomes in the nucleus by half
What is during prophase I the replicated chromosomes pair up in their homologous pairs. Each of these is called a bivalent. In metaphase I the bivalents line up on the equator and a spindle fibre attaches to each chromosome. During anaphase I the homologous pairs are pulled apart by contraction of the spindle fibres and the centromeres do not split. This is called the reduction division as the number of chromosomes is halved in each cell after cytokinesis I has taken place. Now follows the second division which separates the sister chromatids. During anaphase II the centromeres spilt. After cytokinesis II each nucleus contains half amount of genetic material as in the original nucleus
500
Explain how the structure of mitochondrion allows it to carry out its function efficiently
What is the function of the mitochondrion is to carry out aerobic respiration. There are 2 parts. First part is Krebs cycle which takes place in the matrix. This is a solution similar to cytoplasm and contains all the enzymes both for Krebs cycle and the preceding link reaction. The starting point is pyruvate and this is transported from the cytoplasm thu specific diffusion channels in the mitochondrial membranes. The second part is oxidative phosphorylation and this take part on the inner membrane. Embedded in the membrane are the electron carriers and proton pumps as well as ATP synthase which looks like a stalked particle. Embedding these molecules in the membrane allows them to be fixed next to each other therefore making it easier for the electrons to flow in the correct sequence. This inner membrane is highly folded therefore increasing its surface area. As electrons flow through the carriers, protons are pumped into the inner membrane space and form here diffuse back into the matrix via ATP synthase. This flow of protons is aided by the fact that the inter-membrane space is narrow and so a high concentration of protons is easily built up
500
Explain why the light dependent reactions of photosynthesis can only continue for a short time in the dark
What is the light independent reactions form a cyclic pathway that is driven by two products of the light dependent reactions. These are ATP and NADPH + H+ . The NADPH + H+ is used to reduce glycerate 3-phosphate to triose phosphate and the ATP supplies energy for this convresion. If the LDR stops then so does the formation of both ATP and NADPH + H+. Thus reduction of glycerate 3-phosphate stops and so no more triose phosphate is formed. The triose phosphate is used to reform ribulose bisphosphate and so formation of this stops too. Once all of the existing RuBP has been converted into glycerate 3-phosphate by reaction with carbon dioxide no further reactions at all will take place. The amount of GP levels off at a max. and the amount of RuBP and TP drop to zero.
500
Outline the effect of temperature, light intensity, and carbon dioxide concentration on the rate of photosynthesis
What is light- the rate of photosynthesis as light intensity increases, photosynthetic rate reaches plateau at high light levels. CO2- photosynthetic rate rises as CO2 concentration rises, up to a max when rate levels off. Temperature- rate of photosynthesis increases with increase in temperature, up to optimal level/max, high temperatures reduce rate of photosynthesis