science challemge exam

Prokaryotes vs Eukaryotes

  • Cell Structure and Function:

    • Prokaryotes: Unicellular, no nucleus, smaller size (0.1-5.0 micrometers), DNA in nucleoid region.
    • Eukaryotes: Can be unicellular or multicellular, have a nucleus, larger size (10-100 micrometers), DNA in linear chromosomes within nucleus.

  • Organelles:

    • Nucleus:
    • Eukaryotes have a defined nucleus containing genetic material; prokaryotes do not have a nucleus, and their genetic material is found in the nucleoid.
    • Plasma Membrane:
    • Both cell types have a plasma membrane that encloses the cell components.
    • Mitochondria:
    • Present in eukaryotes; have their own mitochondrial DNA (mtDNA) inherited maternally.
    • Chloroplast:
    • Present in plant eukaryotes; contain chlorophyll and their own chloroplast DNA (cDNA) involved in photosynthesis.
    • Vacuoles:
    • Plant cells have large central vacuoles for storage and maintaining cell turgor; animal cells have smaller vacuoles.

  • Cell Cycle:

    • Interphase:
    • Preparatory phase; consists of G1 (growth), S (synthesis), and G2 (growth and preparation for mitosis).
    • Mitosis:
    • Division of the nucleus; includes prophase, metaphase, anaphase, and telophase.
    • Cytokinesis:
    • Division of the cytoplasm following mitosis.
    • Asexual Reproduction:
    • Involves mitosis; results in genetically identical offspring.
    • Sexual Reproduction:
    • Involves meiosis; results in genetically diverse organisms.

DNA vs RNA

  • Basic Genetics:
    • DNA: Deoxyribonucleic acid, double-stranded, stores genetic information.
    • RNA: Ribonucleic acid, single-stranded, involved in protein synthesis.
  • Mendelian Genetics:
    • Dominant alleles are expressed over recessive alleles; alleles determine traits.
  • Punnett Square:
    • Tool used to predict genotypic and phenotypic outcomes of genetic crosses between individuals.

Physical Science/Chemistry

  • Atom:
    • Composed of subatomic particles:
    • Protons: Positive charge, found in the nucleus.
    • Neutrons: No charge, found in the nucleus.
    • Electrons: Negative charge, found in electron cloud around the nucleus.
  • Chemical Reactions:
    • Involve the breaking and forming of chemical bonds; reactants transform into products.
  • Physical vs Chemical Reactions:
    • Physical changes do not alter the chemical identity of substances; chemical changes result in new substances.
  • Properties of Water:
    • Cohesion and adhesion, high specific heat, solvent properties, expands upon freezing, and participates in chemical reactions.