13Explain the causes of sickle-cell anemia Explain the causes of sickle-cell anemia.  M11/4/BIOLO/HP2/ENG/TZ2/XXcaused by gene mutation;(sickle-cell anemia) due to a base substitution (mutation);changes the code on the DNA;which leads to a change in transcription / change in mRNA;DNA changes from CTC to CAC/GAG toGTG / mRNA changes from GAG to GUG;(accept DNA changes from CTT toCAT/GAA to GTA / mRNA changesfrom GAA to GUA)which (in turn) leads to a change in translation / change in polypeptide chain/protein;(the tRNA) adds the wrong amino acid to the polypeptide chain;glutamic acid replaced by valine;produces abnormal hemoglobin;causing abnormal red blood cell/erythrocyte shape / sickle shape;which lowers the ability to transport oxygen;sickle-cell allele is codominant;homozygote/HbS HbS have sickle cell anemia/is lethal / heterozygote/HbS HbA hasthe sickle trait/is carrier (and is more resistant to malaria);
14Explain the cause of sickle cell anemia and why it has been selected through natural selection.  M08/4/BIOLO/SP2/ENG/TZ1/XX+
15Explain the effect of base substitution mutation in sickle cell anemia.  N07/4/BIOLO/HP2/ENG/TZ0/XX+
20Define: Homologous chromosomes: matching pairs of chromosomes
214.2: MeiosisSTATE: Meiosis is a reduction division of a diploid nucleus to form haploid nucleiDiploid: # of chromosomes in a body (somatic) cell (2n)Haploid: # of chromosomes in a sex cell (n)
22Prophase I of Meiosis IHomologous chromosomes pair up forming a synapsis and crossing over occursNuclear membrane breaks downChromosomes condense and supercoilSpindle microtubules develop from the centrioles.
23Metaphase I of Meiosis I Microtubules attach to chromosomes.Homologous chromosomes are “pushed and pulled” by microtubles to the equator of the cell.
24Anaphase I of Meiosis IHomologous chromosomes separate and are pulled to opposite poles.Chromosomes are still in their duplicated form.Cytokinesis occurs
25Telophase I of Meiosis I Chromosomes arrive at the polesChromosomes number is reduced by half.Chromosomes uncoilNew nuclear membrane reforms.Microtubules break down
26Prophase II of Meiosis II Nuclear membrane breaks downChromosomes supercoilCentrioles move to the poles and spindle microtubules develop
27Metaphase II of Meiosis II Spindle microtubules attach to chromosomes and move chromosomes to the equator of the cell
28Anaphase II of Meiosis II Sisiter chromatids separate (and are now are called chromosomes) are pulled towards opposite poles
29Telophase II of Meiosis II Chromosomes uncoilNuclear membrane reformsCytokinesis
30Meiosis: Type of nuclear division in which one parent diploid nucleus divides into four daughter haploid nuclei, eachgenetically different to each other.
55Describe the causes of Down syndrome.  M11/4/BIOLO/HP2/ENG/TZ2/XX Down syndrome is caused by non-disjunction;occurs during meiosis;chromosome pairs fail to separate in meiosis I / chromatids in meiosis II /anaphase II;some gametes have an extra chromosome;can lead to zygotes/individuals with an extra chromosome / individual has47 chromosomes;in Down syndrome this would be trisomy 21/extra chromosome 21;increased probability with increased age of mother/ages of parents; [5 max]
56The karyotype below shows the chromosomes from a person with Down syndrome. M11/4/BIOLO/SP2/ENG/TZ2/XXState the evidence provided by the karyotype that shows this person has Down syndrome. Outline how Down syndrome occurs due to meiosis. (c) Determine, giving a reason, the sex of the person in the karyotype. (d) Explain briefly why males are more likely to inherit colour blindness than females. 
57Explain how an error in meiosis can lead to Down syndrome Explain how an error in meiosis can lead to Down syndrome.  M10/4/BIOLO/HP2/ENG/TZ2/XX+non-disjunction;chromosomes/chromatids do not separate / go to same pole;non-separation of (homologous) chromosomes during anaphase I;due to incorrect spindle attachment;non-separation of chromatids during anaphase II;due to centromeres not dividing;occurs during gamete/sperm/egg formation;less common in sperm than egg formation / function of parents' age;Down syndrome due to extra chromosome 21;sperm/egg/gamete receives two chromosomes of same type;zygote/offspring with three chromosomes of same type / trisomy / total 47 chromosomes; [8 max]Accept the above points in an appropriately annotated diagram.
67What are the Symptoms of Edwards Syndrome? About 25% of Edward'ssyndrome victims diebefore they are one month old,10% live for one year.Symptoms*Growth deficiency*Breathing difficulties*Developmental delays
68STATE: Karyotyping is performed using cells collected by chorionic villus sampling or amniocentesis, for pre natal diagnosis of chromosome abnormalities.4.2.6:
714.3.1:Genotype / PhenotypeGenotype: The combination of alleles an individual has for a particular characteristicPhenotype: The physical appearance of a feature
724.3.1:Dominant / Recessive Alleles Dominant allele: an allele that has the same effect on the phenotype whether it is present in the homozygous or heterozygous state.Recessive allele: an allele that only has an effect on the phenotype when present in the homozygous state.brown eyes brown eyes blue eyes
734.3.1: Co-dominant allelesCodominant alleles: pairs of alleles that both affect the phenotype when present in a heterozygote.
100The diagram below represents the results of a paternity investigation The diagram below represents the results of a paternity investigation. Track A is theprofile of the mother of a child, track B is the profile of the child and track C is the profileof a man who might be the father. M11/4/BIOLO/SP2/ENG/TZ1/XXExplain, using evidence from the diagram, whether this man is the father or not. M11/4/BIOLO/SP2/ENG/TZ1/XX
101N07/4/BIOLO/SP2/ENG/TZ0/The diagram below shows a DNA profiling of a family with five children. Segments of theDNA inherited by some members of the family are shown as two dark bands in each column.The DNA fragments are labelled A to F.State two properties of the fragmented pieces of DNA which allow them to be separated in gel electrophoresis.b. Determine which DNA fragment Son 2 inherited from his mother and which fromhis father.From his mother: From his father:c. Identify the child that genetically most resembles one of the grandparents. d. Apart from determining family relationships, outline one other application forDNA profiling.
1044.4.6: Possible Advantages to the HGP (know three of these) Improves our ability to conduct genetic screening for genetic disorders.Improves our ability to develop new drugs for genetic diseases. (Molecular medicine).Improves our ability to use DNA in the study of evolution and human dispersal out of Africa.Match organ donors with recipients in transplant programs.Elucidating the function of the large proportion of DNA we know little about.
108(b) (i) Label the diagram below which shows a basic gene transfer.  (ii) State two general types of enzymes used in gene transfer.
109(a) Gene transfer to bacteria often involves small circles of DNA into which genes can be inserted. State the name of a small circle of DNA, used for DNA transfer, in bacteria.(b) The diagram below shows a cut circle of DNA into which a gene is being inserted. Beforeit can be transfered into a bacterium, the ring must be altered, using an enzyme.M10/4/BIOLO/SP2/ENG/TZ1/XXOutline what must be done next to complete the process of gene insertion into theDNA circle, including the name of the enzyme that is used.(c) Discuss the potential benefit and possible harm of one named example of gene transfer between species.
1104.4.7: Transfer of Genetic Material Across Species State: That, when genes are transferred between species the amino acid sequence of polypeptides translated from them is unchanged- because the genetic code is universal.
112State: that, when genes are transferred between the amino acid sequence of polypeptides translated from them is unchanged- because the genetic code is universal.
113The diagram below shows a cut circle of DNA into which a gene is being inserted. Before it can be transferred into a bacterium, the ring must be altered, using an enzyme. M10/4/BIOLO/SP2/ENG/TZ1/XXOutline what must be done next to complete the process of gene insertion into theDNA circle, including the name of the enzyme that is used. Discuss the potential benefit and possible harm of one named example of gene transferbetween species. 
114Outline a basic technique for gene transfer involving plasmids Outline a basic technique for gene transfer involving plasmids.  M08/4/BIOLO/HP2/ENG/TZ2/XX
1154.4.9: State two examples of Genetically Modified Crops or Animals GOLDEN RICEGolden rice is a variety of rice that has been genetically modified to produce beta-carotene (a precursor of vitamin A). Golden rice has the potential to prevent blindness or death in populations with vitamin A deficiency.BT CORNBT corn is a variety of corn that has been genetically modified to produce a bacterial toxin. The toxin is not harmful to people but it kills caterpillars. The advantage of BT corn is that it doesn't need to be sprayed with pesticides.
1164.4.10: Benefits/Harmful Effects of GMOs Advantages of Genetically Modified corn are: 1) it increases profits for farmers by saving them the expense of spraying pesticides; 2) it keeps the price of corn lower for consumers; and 3) it saves the environment from toxic pesticides, which can pose heath risks to people and can kill non-target species that with important roles in the ecosystem.Disadvantages are: 1) insect pests may develop resistance to the GM corn because continual exposure to the toxins will speed up the rate of natural selection; and 2) GM corn may produce toxic pollen, release it into the air, and harm beneficial species like the monarch butterfly(although recent studies do not support this claim).
117Genetic modification involves the transfer of DNA from one species to another. Discuss the potential benefits and possible harmful effects of one example of genetic modification in a named organism.  M07/4/BIOLO/SP2/ENG/TZ1/XX
118Two examples of genetically modified crops or animals 1. Bt Maize2. Golden riceDescribe the genetic modification to produce Bt MaizePotential Benefits of Bt MaizePossible harmful effects of Bt Maize
1194.4.11: Clone: Genetically identical organisms or a group of cells derived from a single parent cell.
1204.4.12: Outline a techniques for cloning using differentiated animal cells