Topic 3: Genetics

• What is an allele?

  A version of a gene
• What are amino acids?

  Small molecules from which proteins are assembled
• What is an anticodon?

  A triplet sequence of bases on a tRNA molecule that is complementary to a specific codon in mRNA
• What is asexual reproduction?

  A form of reproduction involving a single parent that creates genetically identical offspring
• What is a base triplet?

  A sequence of three bases in a gene that codes for a particular amino acid
• What are the classifications of blood groups?

  A, B, or O based on surface antigens on red blood cells
• What is a chromosome?

  A long, coiled molecule of DNA that carries genetic information in the form of genes
• What is coding DNA?

  A sequence of DNA that codes for the production of a protein
• What is codominance?

  When both alleles for a gene in a heterozygous organism equally contribute to the phenotype
• What is complementary base pairing?

  Describes how weak hydrogen bonds form between complementary base pairs
• What is detergent used for in DNA extraction?

  To disrupt cell membranes
• What is a diploid cell?

  A cell that contains two copies of each chromosome
• What is DNA?

  A double-stranded polymer that carries the genetic code
• What does dominant mean in genetics?

  Describes an allele that is always expressed
• What is environmental variation?

  Differences in phenotype acquired during the lifespan of an organism due to environmental factors
• What is a family pedigree?

  A chart used to show the inheritance of genetic disorders in a family
• What is fertilisation?

  The fusion of the nucleus of male and female gametes
• What are gametes?

  Sex cells with half the usual number of chromosomes
• What is a gene?

  A length of DNA on a chromosome that codes for the production of a specific protein
• What is genetic variation?

  Differences in the genotypes of organisms of the same species due to the presence of different alleles
• What is a genome?

  The complete genetic material of an organism
• What is a genotype?

  An organism’s genetic composition
• What is sexual reproduction?

  It involves the joining of male and female gametes, each containing genetic information.
• What is a haploid cell?

  A cell that contains a single copy of each chromosome
• What does heterozygous mean?

  When someone has two different alleles of a gene
• What does homozygous mean?

  When someone has two identical alleles of a gene
• What was the Human Genome Project?

  An international research project that successfully mapped the entire human genome
• What are the gametes in animals and flowering plants?

  Sperm and egg cells in animals; pollen and egg cells in flowering plants.
• What is meiosis?

  A form of cell division that produces four genetically different daughter cells with a haploid number of chromosomes
• What is monohybrid inheritance?

  The inheritance of a single gene
• What is mRNA?

  A polymer of nucleotides that carries genetic information from the nucleus to the ribosomes
• How are gametes formed?

  Gametes are formed by meiosis, resulting in non-identical cells.
• What are multiple alleles?

  The existence of more than two alleles of a gene
• What is a mutation?

  A random change in the base sequence of DNA which may result in genetic variants
• How many chromosomes does a normal human cell have?

  A normal cell has 46 chromosomes, or 23 pairs.
• What is non-coding DNA?

  DNA which does not code for a protein but controls gene expression
• What happens during fertilization?

  Each gamete with 23 chromosomes fuses to produce a cell with 46 chromosomes.
• What are nucleotides?

  The monomers of DNA consisting of a sugar, a phosphate group, and a base
• What is the significance of genetic variation in offspring?

  It increases the likelihood that some individuals will survive if the environment changes.
• What is a phenotype?

  An organism’s observable characteristics due to interactions of the genotype and the environment