SCI reviewer

• Cell division


  A process that cells go through to survive
• Types of cell division

  • Mitosis
  • Meiosis
• Body cells (somatic cells)

  Undergo mitosis
• Sex cells (gametes)

  Undergo meiosis
• Cell


  The basic unit of life
• Organelles


  Directly involved in cell division
• Nucleus


  The control center of the cell, bounded by a nuclear membrane, contains genetic material DNA
• DNA


  A double-stranded nucleic acid that is tightly coiled around proteins called histones to form chromosomes
• Nucleotides


  Small units that make up a molecule of DNA, consisting of a sugar, phosphate group, and nitrogen base
• DNA makes a copy of itself in a process called DNA replication
• Chromosome

  Contains long coded message called genes
• Mitosis


  Ensures that the daughter cells receive the exact copy of the DNA of the parent cell
• Centriole


  A small cylindrical structure in the cytoplasm of most eukaryotes
• Cell cycle


  A complex process involving special proteins that control the switching on and off of the four phases: G1, S, G2, and M
• Cyclin dependent kinase (CDK)


  One of the major control switches that signals the cell to proceed from Gap 1 (G1) to synthesis (S)
• Tumor protein p53


  A protein that blocks the cell cycle if the DNA is damaged, and may lead to cell death or apoptosis
• Cell cycle phases

  1. G1 (first growth phase)

  2. S (DNA replication)

  3. G2 (second growth phase)

  4. M (mitosis)
• Mitosis

  1. Prophase

  2. Metaphase

  3. Anaphase

  4. Telophase

  5. Cytokinesis
• Meiosis


  Ensures that the number of chromosomes is maintained among the same species
• Forms of gametogenesis

  • Spermatogenesis (production of sperm cells)
  • Oogenesis (production of egg cells)
• Meiosis involves two divisions: meiosis I and meiosis II
• Chromosome


  Contains a complex molecule called deoxyribonucleic acid (DNA) that contains genes
• Genes


  Determine the traits that an organism possesses
• Types of traits

  • Specific traits (characteristics that make a particular species different from another)
  • Individual traits (characteristics that make one organism different from others)
• Theory of blending inheritance


  The genetic material of the offspring is a uniform blend of the parents
• Heredity


  The transmission of genes from parents to offspring
• Genetics


  The science of heredity
• Mendelian Genetics


  The pattern of inheritance following Mendel's principles
• Gregor Johann Mendel


  An Austrian monk and botanist, regarded as the father of genetics
• Dominant trait


  A trait that seems to dominate the hidden or unexpressed recessive trait
• Recessive trait


  A trait that is hidden or unexpressed in the presence of a dominant trait
• Principle of dominance and recessiveness


  A factor may be dominant or recessive, and the two factors for each trait separate and independently assort into separate gametes
• Allele


  One of the forms a gene has for a particular trait
• Homozygous


  An individual with two identical alleles for a particular gene
• Heterozygous


  An individual with two different alleles for a particular gene
• Gene locus


  A particular location on a pair of homologous chromosomes
• Test cross


  A way to determine whether an organism that expressed a dominant trait was a heterozygote or a homozygote
• Monohybrid cross


  A cross involving just one gene
• Punnett square


  A square diagram used to predict the genotypes of a particular cross or breeding experiment
• Genotypic ratio


  The probable allele combination of any two gametes