Term
| Difference between two species |
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Definition
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Term
| Difference within a species |
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Definition
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Term
| Why might sampling not be representative |
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Definition
| sampling bias - investigators either purposely or unwittingly make unrepresentative choices, or chance |
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Term
How to minimise sampling bias
How to minimise chance? |
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Definition
Random sampling, with the areas sampled decided by computer
Larger sample size, statistical analysis |
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Term
| Genetic variation arises as a result of: |
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Definition
| Mutations, Meiosis - mixes up genetic material before forming gametes, fusion of gametes - genes from both parents |
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Term
| Environmental variation can come as a result of: |
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Definition
| Food availability, Habitats, competition, poor light or soil pH (plants) |
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Term
| Samples based on physical features are placed on a ________________ when they are put on a graph, and this is ______ |
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Definition
| normal distribution curve, bell shaped |
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Term
| The maximum height of a normal distribution curve is the ______ of the sample |
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Definition
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Term
| ________ of the measurements in a normal distribution curve lie within _________ and __________ lie within _______ |
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Definition
| 68, +/- 1 standard deviation, 95, +/- 2 standard devation |
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Term
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Definition
/Σ(x-y)2
√
----------
n
where x= measured value
y = mean value
n= total number of values |
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Term
| Individual nucleotides of DNA are made up of: |
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Definition
| a deoxyribose sugar, a phosphate group, an organic base, A, T, C or G |
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Term
| Nucleotides are made with: |
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Definition
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Term
| Mononucleotides are joined together with: |
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Definition
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Term
Adenine pairs with _________ using _______ hydrogen bonds
Guanine pairs with _________ using _______ hydrogen bonds |
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Definition
| Thymine, two, Cytosine, three |
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Term
| How is DNA adapted to carry out its functions? |
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Definition
| Very stable, strands only joined with hydrogen bonds, allows them to separate, very large molecule, deoxyribose/phosphate backbone protects bases |
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Term
| There are __ pairs of DNA in one full turn of the helix |
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Definition
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Term
| In the experiment where mice were infected with the dead harmful version of pneumonia and the live safe version, what happened when both were injected and why, and why was this significant? |
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Definition
| the mice died, the life safe version took the information of how to produce the toxin from the dead version, it allowed them to test for substances that allowed this (e.g. DNA) |
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Term
| How was the mouse experiment further investigated and what did this prove? |
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Definition
| the substances in the bacteria were isolated and and purified, the only substance that produced the transformation was the DNA |
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Term
| How many bases code for each amino acid, and what is this called? |
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Definition
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Term
| What are the features of the triplet code? |
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Definition
Some amino acids have one triplet code, most have between 2 and 6
It is always read in one direction
methionine is always the first amino acid coded for, and if not needed is later removed, the code is non-overlapping, the code is universal (mostly) |
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Term
| When visible, chromosomes appear as: |
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Definition
| two threads, known as chromatids, joined by a centromere |
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Term
In prokaryotic cells, DNA is:
In eukaryotic cells, DNA is: |
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Definition
circular and smaller, plasmids
larger and linear, chromosomes |
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Term
| Humans have ________ chromosomes |
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Definition
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Term
| Meiosis produces ___ daughter cells with ____ the number of chromosomes |
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Definition
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Term
| In meiosis 1, the ________ pair up, and their ____________, Portions of ________ are exchanged through crossing over |
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Definition
| homologous chromosomes, chromatids wrap around each other, chromatids |
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Term
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Definition
| a different form of a gene |
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Term
| In meiosis 2, the _____ move apart and __ cells are formed |
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Definition
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Term
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Definition
| a section of DNA that codes for a polypeptide |
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Term
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Definition
| The position of the gene on a chromosome or DNA molecule |
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Term
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Definition
| the random combination of chromosomes that goes into the daughter cells in meiosis 1 |
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Term
| Genetic recombination by crossing over |
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Definition
| when the chromatids are twisted round each other, bits break off and then rejoin, sometimes to the other chromatid, producing new genetic information |
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Term
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Definition
| occurs when a small group of individuals colonise new land, the small fraction of the alleles they carry leads to reduced genetic diversity in the new community |
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Term
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Definition
| when the population of a species drops drastically normally due to a natural disaster. the population may recover, but many alleles will be lost, and the new population will have a lower genetic diversity |
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Term
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Definition
| the number of different alleles that all members of a species possess, higher genetic diversity means greater adaption to change |
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Term
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Definition
primary = four polypeptide chains
secondary = polypeptides coiled into helix
tertiary = each polypeptide folded into precise shape to carry O2
quaternary = all four polypeptides linked together to form molecule, each polypeptide linked to a haem group with iron, each iron can carry 1 O2, four O2 in total |
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Term
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Definition
| It must readily associate with O2 at the surface where gas exchange occurs, and readily disassociate with O2 at the tissues requiring it |
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Term
| Haemoglobin releases O2 at the tissues because |
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Definition
| the higher Co2 concentration changes its shape |
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Term
| The further to the left the oxygen disassociation curve is, the |
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Definition
| greater the affinity the haemoglobin has for oxygen |
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Term
| The further to the right the oxygen disassociation curve is, the |
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Definition
| lower the affinity the haemoglobin has for oxygen |
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Term
| smaller animals have oxygen dissociation curves further to the _____ as they ________ |
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Definition
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Term
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Definition
| alpha glucose in a helix joined together by glycosidic bonds |
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Term
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Definition
| insoluble, compact, hydrolyses to form alpha glucose |
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Term
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Definition
| shorter chains to starch, more branched, alpha glucose |
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Term
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Definition
| insoluble, compact, hydrolyses to form alpha glucose |
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Term
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Definition
| Beta glucose, straight unbranched chains running parallel to each other, held in place by hydrogen bonds cross linkages |
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Term
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Definition
| strong, structural, rigid |
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Term
| Features of Leaf Palisade cell |
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Definition
long and thin to absorb sunlight
numerous chloroplasts
large vacuole |
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Term
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Definition
| double plasma membrane, grana and thylakoids that contain chlorophyll, stroma where photosynthesis occurs |
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Term
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Definition
| cellulose, middle lamella between cells |
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Term
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Definition
| the process by which the nucleus divides |
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Term
| Semi-conservative replication |
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Definition
| DNA helicase breaks the hydrogen bonds, causing the double helix to unwind. The polypeptide strands then act as templates, and complementary nucleotides are attached. DNA polymerase then joins the polynucleotides back together, and both the new strands have half the original |
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Term
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Definition
Interphase - cell normal
Prophase - chromosomes become visible, Nuclear envelope disappears
Metaphase - chromosomes arrange themselves on equator of cell, spindle fibres form
Anaphase - spindle fibres contract, chromatids moved to poles of cell
Telophase - chromosome reach poles and become indistinct, nuclear envelope and nucleolus reform, spindle disapears |
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Term
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Definition
growth
cell differentiation
repair |
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Term
| Cells becoming specialised = |
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Definition
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Term
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Definition
| cells aggregated together |
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Term
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Definition
| Different types of tissues working together |
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Term
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Definition
| Organs working together, such as Digestive, respiratory and circulatory system |
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Term
| Features of exchange surfaces |
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Definition
large SA to Vol ratio
thin, so the diffusion distance is short
partially permeable
movement of external and internal mediums |
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Term
| Diffusion is proportional to |
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Definition
surface area x difference in concentration
------------------------------------
length of diffusion path |
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Term
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Definition
| an internal network of tubes in insects |
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Term
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Definition
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Term
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Definition
| along a diffusion gradient, and through ventilation by moving the muscles in the tracheae |
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Term
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Definition
| Pores that open and close the tracheae |
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Term
| Gill filaments are stacked up at ____________ and have __________- on them to _______________ |
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Definition
| right angles, lamella, increase surface area |
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Term
| Counter-current principle |
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Definition
Blood flows one way, water the other, concentration gradient stays, like this
water 10 7 5 4 2 ->
Blood 9 6 4 3 1 <- |
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Term
| How are leaves adapted for gaseous exchange? |
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Definition
| thin, flat shape for surface area, many stomata, numerous air spaces |
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Term
| Photosynthesis produces _________ and uses __________ |
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Definition
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Term
| Respiration in plants produces _________ and uses __________ |
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Definition
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Term
| Features of a transport system |
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Definition
| suitable medium to carry materials closed system of vessel |
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Term
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Definition
| Tough outer layer, muscle layer, elastic layer, thin inner lining, lumen |
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Term
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Definition
| formed from blood plasma, forced out of the capillaries at the end by the hydrostatic pressure, contains glucose, amino and fatty acids, salt and oxygen |
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Term
| Movement of water through a plant |
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Definition
| Uptaken by root hairs along concentration gradient, moves by osmosis into root hair cell, travels along apoplastic pathway (along cell walls) and symplastic pathway (diffusing from cell to cell) when the apoplastic meets the casparian strip it is forced into the protoplast of the cell as the casparian strip is waterproof, and there it meets the symplastic pathway. water then moves into the xylem by osmosis, and it moves up due to cohesion between water molecules as water is being used in photosynthesis and also evaporating from the leaves |
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Term
| Root hair cells are effective as |
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Definition
| they provide a large surface area and have a thin surface layer to speed diffusion |
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Term
| Factors affecting transpiration |
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Definition
| Light, temperature humidity, air movement |
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Term
| Xerophytes are adapted to survive in __________ conditions. how are they adapted to this |
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Definition
| waterless, thick cuticle to reduce evaporation, rolling up of leaves, hairy leaves and stomata in pits to create humidity around the leaf and prevent water moving out, and reduced size of leaves |
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Term
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Definition
| similar to each other but different to members of other species and capable of breeding to produce fertile offspring |
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Term
| Species are named using the ______ system, the |
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Definition
| binomial, first name is genus, second is species |
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Term
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Definition
Artfificial - based on differences such as colour, shape size, number of legs
Natural- based on evolutionary relationships |
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Term
| The phylogenetic groups are _________ what does this mean |
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Definition
| hierarchal, they are arranged into groups contained within larger groups with no overlap |
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Term
| King Prawn Curry Or Fresh Green Salad |
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Definition
| Kingdom Phylum Class Order Family Genus Species |
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Term
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Definition
| Two genes that code for the same thing from different species are taken, mixed together, heated until the hydrogen bonds break, mixed again, and then allowed to form bonds between the different strands. They are then heated again until they break, and the temperature at which they were shows the amount of hydrogen bonds formed. The more formed the closer they were |
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Term
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Definition
| sequencing the three genes found in all plants to see how close they are too each other |
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Term
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Definition
| Identifies members of own species that are capable of breeding and at the time too |
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Term
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Definition
| One bacteria extends a pilus to the other, copies a plasmid, breaks it to make it linear, passes it through the conjugation tube, then the tunbe retracts and the plasmid becomes circular again |
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Term
| Species diversity refers to |
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Definition
| the number of different species in a community |
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Term
| Things that reduce species diversity |
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Definition
| Agriculture, deforestation,disease |
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