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.