Topic+4

__4.1 Chromosomes, genes, alleles and mutations__

 * 4.1.1 ||
 * State that eukaryote chromosomes are made of DNA and proteins. ||
 * 4.1.2 ||
 * Define gene, allele and genome. ||
 * 4.1.3 ||
 * Define gene mutation. ||
 * 4.1.4 ||
 * Explain the consequence of a base substitution mutation in relation to the processes of transcription and translation, using the example of sickle-cell anemia. ||
 * 4.1.4 ||
 * Explain the consequence of a base substitution mutation in relation to the processes of transcription and translation, using the example of sickle-cell anemia. ||
 * Explain the consequence of a base substitution mutation in relation to the processes of transcription and translation, using the example of sickle-cell anemia. ||


 * 4.2.1 ||
 * State that meiosis is a reduction division of a diploid nucleus to form haploid nuclei. ||
 * 4.2.2 ||
 * Define homologous chromosomes. ||
 * 4.2.3 ||
 * Outline the process of meiosis, including pairing of homologous chromosomes and crossing over, followed by two divisions, which results in four haploid cells. ||
 * 4.2.4 ||
 * Explain that non-disjunction can lead to changes in chromosome number, illustrated by reference to Down syndrome (trisomy 21). ||
 * 4.2.5 ||
 * State that, in karyotyping, chromosomes are arranged in pairs according to their size and structure. ||
 * 4.2.6 ||
 * State that karyotyping is performed using cells collected by chorionic villus sampling or amniocentesis, for pre-natal diagnosis of chromosome abnormalities. ||
 * 4.2.7 ||
 * Analyse a human karyotype to determine gender and whether non-disjunction has occurred. ||
 * 4.2.6 ||
 * State that karyotyping is performed using cells collected by chorionic villus sampling or amniocentesis, for pre-natal diagnosis of chromosome abnormalities. ||
 * 4.2.7 ||
 * Analyse a human karyotype to determine gender and whether non-disjunction has occurred. ||
 * 4.2.7 ||
 * Analyse a human karyotype to determine gender and whether non-disjunction has occurred. ||

__4.3__ __Theoretical genetics__
4.3.9 State that a human female can be homozygous or heterozygous with respect to sex-linked genes. 4.3.10 Explain that female carriers are heterozygous for X-linked recessive alleles. 4.3.11 Predict the genotypic and phenotypic ratios of offspring of monohybrid crosses involving any of the above patterns of inheritance. 4.3.12 Deduce the genotypes and phenotypes of individuals in pedigree charts.
 * 4.3.1 ||
 * Define genotype, phenotype, dominant allele, recessive allele, codominant alleles, locus, homozygous, heterozygous, carrier and test cross. ||
 * 4.3.2 ||
 * Determine the genotypes and phenotypes of the offspring of a monohybrid cross using a Punnett grid. ||
 * 4.3.3 ||
 * State that some genes have more than two alleles (multiple alleles). ||
 * 4.3.4 ||
 * Describe ABO blood groups as an example of codominance and multiple alleles. ||
 * 4.3.5 ||
 * Explain how the sex chromosomes control gender by referring to the inheritance of X and Y chromosomes in humans. ||
 * 4.3.6 ||
 * State that some genes are present on the X chromosome and absent from the shorter Y chromosome in humans. ||
 * 4.3.7 ||
 * Define sex linkage. ||
 * 4.3.8 ||
 * Describe the inheritance of colour blindness and hemophilia ||
 * State that some genes are present on the X chromosome and absent from the shorter Y chromosome in humans. ||
 * 4.3.7 ||
 * Define sex linkage. ||
 * 4.3.8 ||
 * Describe the inheritance of colour blindness and hemophilia ||
 * 4.3.8 ||
 * Describe the inheritance of colour blindness and hemophilia ||

__4.4__ __Genetic engineering and biotechnology__
|| 4.4.1 Outline the use of polymerase chain reaction (PCR) to copy and amplify minute quantities of DNA. 4.4.2 State that, in gel electrophoresis, fragments of DNA move in an electric field and are separated according to their size. 4.4.3 State that gel electrophoresis of DNA is used in DNA profiling. 4.4.4 Describe the application of DNA profiling to determine paternity and also in forensic investigations. 4.4.5 Analyse DNA profiles to draw conclusions about paternity or forensic investigations. 4.4.6 Outline three outcomes of the sequencing of the complete human genome. 4.4.7 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. 4.4.8 Outline a basic technique used for gene transfer involving plasmids, a host cell (bacterium, yeast or other cell), restriction enzymes (endonucleases) and DNA ligase. 4.4.9 State two examples of the current uses of genetically modified crops or animals. 4.4.10 Discuss the potential benefits and possible harmful effects of one example of genetic modification. 4.4.11 Define clone. 4.4.12 Outline a technique for cloning using differentiated animal cells. 4.4.13 Discuss the ethical issues of therapeutic cloning in humans.

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