Essential Biology 4.1 Chromosomes, Genes, Alleles, Mutations Due Date:
Student Name:
Resources: Clegg pp. 91-94, 98-102 and Revision Guide pp. 23 covering Topic 4.1 .(and some review of transcription and translation!)
1.
Define the following:
Chromosome
Gene
Allele
Gene locus
Genome
Chromatid
Mutation
Haploid
Diploid
2.
State the components of a chromosome.
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DNA &
3.
State the number of chromosomes present in a single human diploid cell.
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4.
Identify structures a. and b. on the line drawing of a chromosome in prophase shown to the right. a.
b.
5.
Give two examples of genes and some of their possible alleles.
Gene Possible alleles
Eye colour Blue, brown, green, hazel
6.
List factors that increase the chance of a genetic mutation.
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Essential Biology 4.1 Chromosomes, Genes, Alleles, Mutations
Student Name:
7.
mRNA amino acid
Due Date:
8.
Distinguish between the two DNA strands above in terms of: a.
DNA base sequence.
 b.
Amino acid sequence in the resulting polypeptide.
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9.
Compare the following types of base-substitution mutation.
Silent mutation Mis-sense mutation Nonsense mutation
Number of bases substituted
1
Effect on polypeptide
Stop codon produced early – polypeptide shortened
Example illness Sickle cell disease
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Essential Biology 4.1 Chromosomes, Genes, Alleles, Mutations
Student Name:
Due Date:
10.
Describe the effects of sickle cell disease on sufferers in terms of: a.
Hemoglobin production
 b.
Symptoms and mortality
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11.
Identify parts of the world where a single sickle cell (Hb s ) allele could be beneficial
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Explain your answer
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12.
Define evolution.
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13.
Outline how mutations lead to evolution by natural selection.
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14.
Outline how the spread of the sickle cell gene is an example of natural selection in action.
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15.
How could this be an example of a correlation which has a strong element of causality?
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Essential Biology 4.1 Chromosomes, Genes, Alleles, Mutations
Student Name:
Due Date:
In-class activity: Using gene databases (ICT Databases)
1.
Using the NCBI gene database at http://www.ncbi.nlm.nih.gov/sites/entrez?db=gene , identify the gene locus of the HBB (hemoglobin) gene.
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2.
Using the same database, look for the gene related to the illness PKU (phenylketonuria) a.
What is the gene name?
 b.
What is the gene locus of this gene?
 c.
Which enzyme is encoded by this gene?
 d.
What is the consequence of a base-substitution (mis-sense) mutation of this gene?
 e.
How is PKU diagnosed and why must it be diagnosed as early as possible?
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3.
Stem cells link:
Read this article: http://notexactlyrocketscience.wordpress.com/2007/12/08/sickle-cell-micecured-by-stem-cells-reprogrammed-from-their-own-tails/ a.
What is an IPS stem cell? b.
Outline the use of this technology in treating the mice with sickle cell disease.
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