Lab notes

• What are prokaryotes?

  Organisms with simple cells that don't have a nucleus. They are uni-cellular.
• What are eukaryotes?

  Organisms with more complex cells. They have a nucleus and are multicellular.
• What are the 3 basic structural parts of a eukaryote cell?

  Nucleus, cytoplasm, cell membrane
• What are the two types of cells in our body?

  Somatic and Gametes.
• What are our tissue cells called?

  somatic
• What are our sex cells called?

  gametes
• What does it mean to have diploid chromosomes?

  Having pairs of chromosomes. You have one maternal and one paternal of each pair. They have the same loci but possibly different alleles on each.
• How many chromosomes do humans have in total?

  46
• How many pairs of sex chromosomes do humans have and what are they?

  1 pair. They are either XX or XY.
• Species differ in chromosome number and genome size.
• Cell division is how cells and organisms make "new ones".
• Mitosis is the duplication of somatic cells. It is DNA replication and one division.
• Mitosis produces exact copies and occurs in somatic cells.
• Mitosis functions in growth and repair.
• The chromosome number for mitosis is 46 diploid.
• How many divisions is mitosis?

  1
• Meiosis makes gametes. Think of my ovaries, sis!
• Meiosis is DNA replication with two divisions that produce unique gametes. The chromosome number is halved creating the haploid chromosome number, 23.
• Recombination or crossing over happens in meiosis. Without it we would be exact clones of our parents.
• Random assortment in meiosis:

  maternal and paternal chromosomes align and migrate into forming gametes randomly
• crossing over/recombination in meiosis:

  exchange of chromosome parts between maternal and paternal members of pair.
• List some problems with Meiosis:

  deletion, duplicaiton, inversion, translocation, insertion, non-disjunct
• What happens with duplication in meiosis?

  Part of the chromosome duplicated, often combined with deletion. Trisomy 21 Downs Syndrome is an example.
• What happens with inversion in Meiosis?

  A portion of the chromosome inverts. Leukemia is caused by this as well as really tall people.
• What is translocation in Meiosis?

  Part of the chromosome connects to another chromosome. This can cause infertility and leukemia.
• What happens with insertion in Meiosis?

  Adds in amino acids multiple times. This causes huntingtons disease.
• What is non-disjunct in meiosis?

  A failure of partner chromosomes or chromosome strands to separate during cell division.
• The blending theory is the idea that if you had one tall parent and one short parent they would have a medium child. Is this true?


  no. Mendel proved that it is not true.
• Alleles are alternate versions of the same gene found on homologous chromosomes.
• What is a dominant allele?

  it is always expressed in the presence of another allele.
• What is a recessive allele?

  It is masked in the presence of a dominant allele, to be expressed you must have two copies.
• What is a genotype?

  an individual's genetic makeup, what alleles an individual possesses.
• What kind of allele is TT?

  Homozygous dominant
• What kind of allele is Tt?

  Heterozygous
• What kind of allele is tt?

  Homozygous recessive
• What is a phenotype?

  An individual's observable characteristics and the expression of the genotype influenced by the environment.
• Genotype is genetic; phenotype is physical.
• Mendelian traits are determined by alleles at single locus. They are the simplest possible pattern of inheritance.
• meiosis = haploid
• mitosis = diploid