Biology Exam #4

• Chromatin


  DNA strand that not visible (uncondensed)
• Chromosome


  • DNA strand
  • Condensed & visible (during cell division)
• Gene


  • Located on chromosome
  • Segments of DNA (sequence of nucleotides) that code for specific protein (trait)
  • (i.e. code for enzymes involved in chemical reactions that produce products that provide traits)
• Locus (loci)


  Location of gene on chromosome
• Autosomal chromosomes


  All chromosomes except sex chromosomes
• Sex chromosomes


  In humans, X or Y
• Allele


  Alternative form of same gene
• Dominant allele


  • If present will mask effect of other alleles
  • Upper case letter
  • (i.e. B)
• Recessive allele


  • Only expressed in phenotype in homozygous recessive individual
  • Lower case letter
  • (i.e. b)
• Homozygous


  • 2 of same of alleles for specific trait
  • (i.e. BB or bb)
• Heterozygous


  • 2 different alleles for specific trait
  • (i.e. Bb)
• Carrier


  • Person who is heterozygous for (recessive trait)
  • Recessive trait not expressed in phenotype
• Genotype


  • Genetic make-up of organism (for trait/ traits)
  • (i.e. BB or bb or Bb)
• Phenotype


  • Physical expression of genotype
  • (i.e. Brown hair or blue eyes)
• Gene expression


  Determines phenotype
• Karyotype

  Graphic of chromosomes arranged by pairs according to size, shape, and general appearance in mitotic metaphase

  Genome

  Complete set of all genes
• Gamete


  Sex cell/ egg & sperm
• Zygote


  Fertilized egg
• Haploid


  • 1 set of chromosomes (n)
  • (i.e. egg or sperm cells)
• Diploid


  • 2 sets of chromosomes (2n)
  • (i.e. All other cells except egg or sperm)
• Genetics


  Study of genes, how genes produce characteristics, and how characteristics are inherited
• Sex-linked traits


  Traits controlled by genes located on sex chromosomes
• X-linked traits

  Control by genes on X chromosome
• Y-linked traits

  Control by genes on Y chromosome
• DNA


  Deoxyribonucleic Acid
• DNA


  • Polymer of nucleotides
  • Sugar: deoxyribose
  • Phosphate group (PO4)
  • Nitrogenous base (A,T,C,G)
  • Double-stranded alpha-helix
  • Located in nucleus
• Complementary base pairing


  • Adenine binds with thymine
  • Cytosine binds with guanine
• Functions of DNA


  • Codes for making enzymes
  • Catalyze cellular reactions
  • Produce chemical products
  • Give us our traits
  • Coordinates activities of cell
• Discoverers of DNA structure

  James Watson, Francis Crick, & Rosalind Franklin
• RNA


  Ribonucleic Acid
• RNA


  • Polymer of nucleotides
  • Sugar: ribose
  • Phosphate group (PO4)
  • Nitrogenous base (A, U, C, G)
  • Adenine, uracil, cytosine, guanine
  • Single stranded
  • Located in nucleus & cytoplasm (& ribosome)
• Types of RNA


  • mRNA (Messenger RNA)
  • tRNA (Transfer RNA)
  • rRNA (Ribosomal RNA)
• mRNA


  • Describes sequence of amino acids to be bonded for protein production
  • Single, straight chain
• tRNA


  • Picks up particular amino acid & brings to ribosome
  • Clover-leaf shape
• rRNA


  Located in ribosome (highly coiled shape)
• Genetic Material

  • Genes located on chromosomes (chromatin-uncondensed)
  • Genes are sequences of DNA
• (General Characteristics of Cancer)

  Non-differentiated cells

  Non specialized
• (General Characteristics of Cancer)

  Uncontrolled growth

  • Repeated, rapid cell divisions
  • Potentially "immortal"/ enter cell cycle repeatedly
  • Most “normal” cells enter cell cycle about 50 times, then die
• (General Characteristics of Cancer)

  Most "normal" cells

  Enter cell cycle about 50 times, then die
• (General Characteristics of Cancer)

  Abnormal nuclei

  Enlarged, abnormal # of chromosomes, etc...