Genetics

Cards (212)

  • Allele
    Alternative form of a gene
  • Autosome
    Chromosome that does not contain a sex determining gene
  • Centromere
    Constricted area on the chromosome where the spindle attaches
  • Chromatin
    DNA wrapped around proteins that is NOT condensed; uncondensed
  • Chromosome
    A structure, consisting of DNA wrapped around histone proteins that carries genes
  • Diploid
    Having two sets of chromosomes in the cell, or a species that contains two copies of each chromosome
  • Expressed
    If a gene is copied and made into an mRNA and protein
  • Gene
    A DNA sequence with a known function (encoding a protein or regulator)
  • Genome
    The complete set of genetic instructions (DNA) characteristic of an organism = 3.2 billion base pairs
  • Genotype
    The actual gene makeup of an individual for a trait, i.e. AA or Aa or aa
  • Haploid
    Having only one set of the genome in the cell
  • Homologous chromosomes (homologs)

    Have the same appearance and carry the same genes (one from mom and one, dad)
  • Locus
    The spot on a chromosome where a gene resides
  • mRNA
    A complimentary copy of a section of DNA (template strand), carries a codon used to make a protein
  • Multifactorial
    A trait determined by one or more genes and the environment
  • Mutation
    A change in the base sequence of a gene
  • Phenotype
    The physical appearance or observable characteristic for a trait, i.e. freckles
  • Polymorphism
    A variation in the DNA sequence that is present in at least 1 percent of the population
  • Sister chromatids
    Two identical chromatids joined at the centromere
  • SNP (Single Nucleotide polymorphism)

    A single base site that varies among individuals in a population, often related to diseases
  • Telomeres
    Segments of DNA at the ends of chromosomes
  • Somatic cell

    A body cell; is diploid; contains 2 sets of chromosomes
  • Reproductive cells
    Gametes = sperm and egg; haploid- have only one set of chromosomes or only one chromosome of each homologous pairs
  • Prokaryotic cells
    DNA is in nucleoid region, DNA is single, circular chromosome; cell wall surrounds plasma membrane
  • Eukaryotic cells
    Had a nucleus, organelles, compartmentalization
  • The Human Genome Project has identified approximately 22,000 genes that encode for proteins
  • Mitosis
    Cell division with normal somatic cells and in development of embryo; one division; 2 daughter 2n cells
  • Meiosis
    Cell division-produce reproductive cells (sperm and egg) reductional; two divisions, 4 daughter cells (n)
  • Tetrad
    4 chromatids linked together in prophase – metaphase of Meiosis I
  • Stages of cell division
    • Interphase (G1, G2, S)
    • Mitosis (Prophase, Prometaphase, Metaphase, Anaphase, Telophase)
    • Cytokinesis
  • AABB
    Homozygous dominant for two traits
  • Homozygous
    Condition when both alleles for a gene are the same
  • Heterozygous
    Condition when the alleles for a gene are different
  • Dominant
    An allele that is fully expressed if present
  • Recessive
    An allele that is only expressed if there are no other alleles present
  • Sex-linked
    Genes carried on the X and Y chromosomes
  • Incomplete dominance
    Heterozygote produces a phenotype intermediate to homozygotes; 1:2:1 Phenotypic
  • Codominance
    Both alleles are expressed in the heterozygote, so there is a 1:2:1 phenotypic ratio
  • Epistasis
    One gene masks the effects of another gene (Labrador retriever) usually produces 9:3;4 ratio
  • Pleiotropy
    One gene has several phenotypic effects