Topic 4- genetics variation

• What is adaptation in biology?


  A feature of an organism that increases its chance of survival in its environment.
• What are the three types of adaptations?

  Anatomical, physiological, and behavioural adaptations.
• What is an allele?


  A version of a gene.
• What is an anticodon?


  A sequence of three nucleotide bases at one end of a tRNA molecule that is specific to an mRNA codon.
• How is the arithmetic mean calculated?

  By dividing the sum of the values by the number of values.
• What is artificial classification?

  A type of classification that divides organisms into groups based on analogous characteristics.
• What is the binomial system?


  A universal system of naming organisms that consists of two parts: the generic name and the specific name.
• What does biodiversity refer to?

  The variety of genes, species, and habitats within a particular area.
• What is the cellular proteome?


  The proteins expressed in a given type of cell.
• What is a chromatid?


  One strand of a replicated chromosome.
• What is a chromosome?

  A structure consisting of a long, coiled molecule of DNA and its associated proteins.
• What is a chromosome mutation?

  A change to the number or structure of chromosomes that can occur spontaneously.
• What is classification in biology?

  The organisation of organisms into groups.
• What is a codon?


  A sequence of three bases on mRNA that codes for a specific amino acid.
• What is conservation in biology?


  The maintenance of ecosystems and biodiversity by humans to preserve the Earth’s resources.
• What is courtship in biological terms?

  The behaviour by which members of a species select reproductive partners.
• What is crossing over in meiosis?

  The process in meiosis 1 where homologous chromosomes exchange alleles at equivalent portions of chromatids.
• What does it mean that the genetic code is degenerate?


  More than one triplet can code for a particular amino acid.
• What is deletion in genetics?


  A form of gene mutation in which one or more nucleotide bases are removed from a DNA sequence.
• What is directional selection?


  A type of selection that favours individuals that differ in one direction from the population mean.
• What is ecosystem diversity?

  A measure of the range of different habitats in a particular area.
• What is eukaryotic DNA?

  Linear molecules of DNA which, together with histones, form chromosomes.
• What is an exon?

  A sequence of DNA that codes for an amino acid sequence.
• What is fertilisation in biological terms?


  The random fusion of haploid gametes to produce a diploid zygote, creating genetic variation.
• What is a gene?

  A length of DNA on a chromosome that codes for the production of one or more polypeptide chains and functional RNA.
• What is a gene mutation?

  A change to at least one nucleotide base in DNA or the arrangement of bases.
• What is the generic name in binomial nomenclature?

  It denotes the organism’s genus and is written in upper case.
• What is the genetic code?

  The rules by which triplets in a DNA base sequence code for the sequence of amino acids in a polypeptide chain.
• What is genetic diversity?

  The number of different alleles in a population.
• What is a genome?

  The entire set of genes in a cell.
• What are histones?


  Proteins that, together with DNA, form chromosomes in the nuclei of eukaryotic cells.
• What are homologous chromosomes?

  A chromosome pair, one paternal and one maternal, with the same gene loci.
• What is independent segregation?

  The random separation of homologous chromosomes in meiosis 1 that produces genetic variation.
• What is the index of diversity (d)?

  It describes the relationship between the number of different species and the abundance of individuals in each of these species within a community.
• How is the index of diversity calculated?


  Using the formula: $d =$$\frac{N(N-1)}{n(n-1)}$, where d is the index of diversity, N is the total number of organisms of all species, and n is the total number of organisms of each species.
• What is an intron?


  A non-coding sequence of DNA.
• What is a locus?

  The position of a gene on a chromosome.
• What is meiosis?


  A type of cell division that produces four genetically different daughter cells with a haploid number of chromosomes.
• What is messenger RNA (mRNA)?


  A type of RNA that carries genetic information from the nucleus to the ribosomes for protein synthesis.
• What is mitosis?


  A form of cell division that produces two genetically identical diploid daughter cells.