ABSTRACT
After reading the following chapter and undertaking personal study, you should be able to:
Describe the structure of a nucleic acid.
Describe the structure of deoxyribonucleic acid (DNA) and compare it with that of ribonucleic acid (RNA).
Define the terms ‘chromatin’, ‘chromosome’, ‘diploid’, ‘haploid’ and ‘gene’ and relate these definitions to normal healthy cells.
In connection with the replication of normal healthy cells, describe the following:
DNA replication.
The cell cycle and mitosis.
How meiosis differs from mitosis.
Describe briefly the three types of RNA – messenger RNA (mRNA), ribosomal RNA (rRNA) and transfer RNA (tRNA).
Differentiate between a codon and an anticodon.
Describe transcription and translation.
Explain the terms ‘locus’, ‘allele’, ‘genotype’, ‘phenotype’, ‘homologous’, ‘homozygous’ and ‘heterozygous’ and relate the explanations to genetic disease.
Identify normal traits that you might see in people that you meet each day and that are examples of simple autosomal inheritance (dominant and recessive), incomplete dominance (co-dominance), multiple alleles and polygenic inheritance.
Use a Punnett square in order to show the possible combination of alleles that may be inherited from parents and relate this to patients in clinical practice.
Give examples of the following patterns of genetic disease – simple autosomal inheritance (dominant and recessive), incomplete dominance (co-dominance) and sex-linked disorders – and give examples from clinical practice.
Describe briefly what is meant by a chromosomal aberration and give an example.
