1.1

• What are the two types of cells?

  Eukaryotic and prokaryotic
• What distinguishes eukaryotic cells from prokaryotic cells?

  Eukaryotic cells have membrane-bound organelles and a nucleus, while prokaryotic cells do not.
• How is genetic information stored in a prokaryotic cell?

  It is found free within the cytoplasm as chromosomal DNA and plasmid DNA.
• What are plasmids?

  Small, circular loops of DNA found free in the cytoplasm, separate from the main DNA.
• What is the function of plasmids in prokaryotic cells?

  They carry genes that provide genetic advantages, such as antibiotic resistance.
• What is a centimetre (cm) in metres?

  1 x 10$-2$ metres
• What is a millimetre (mm) in metres?

  1 x 10$-3$ metres
• What is a micrometre (µm) in metres?

  1 x 10$-6$ metres
• What is a nanometre (nm) in metres?

  1 x 10$-9$ metres
• What are the components of both plant and animal cells?

  • Nucleus
  • Cytoplasm
  • Cell membrane
  • Mitochondria
  • Ribosomes
• What are the additional components found in plant cells?

  • Chloroplasts
  • Permanent vacuole
  • Cell wall
• What is the function of the nucleus other than storing genetic information?

  It controls cellular activities.
• Describe the structure of the cytoplasm.

  It is a fluid component of the cell containing organelles, enzymes, and dissolved ions and nutrients.
• What is the function of the cytoplasm?

  It is the site of cellular reactions and acts as a transport medium.
• What is the function of the cell membrane?

  It controls the entry and exit of materials into and out of the cell.
• What is the function of the mitochondria?

  It is the site of later stages of aerobic respiration where ATP is produced.
• What is the function of ribosomes?

  They join amino acids in a specific order during translation for protein synthesis.
• What is the plant cell wall made of?

  Cellulose
• What is the function of the plant cell wall?

  It provides strength and prevents the cell from bursting when water enters by osmosis.
• What does the permanent vacuole contain?

  Cell sap, a solution of salts, sugars, and organic acids.
• What is the function of the permanent vacuole?

  It supports the cell, maintaining its turgidity.
• What is the function of chloroplasts?

  They are the site of photosynthesis.
• How are sperm cells adapted to their function?

  • Haploid nucleus contains genetic information.
  • Tail enables movement.
  • Mitochondria provide energy for tail movement.
  • Acrosome contains enzymes that digest the egg cell membrane.
• How are nerve cells adapted to their function?

  • Long axon transmits electrical impulses.
  • Dendrites connect to receive impulses from other cells.
  • Myelin sheath insulates the axon and speeds up impulse transmission.
• How are muscle cells adapted to their function?

  • Arrangement of protein filaments allows contraction.
  • Mitochondria provide energy for contraction.
  • Merged cells allow contraction in unison.
• How are root hair cells adapted to their function?

  • Large surface area for nutrient and water absorption.
  • Thin walls facilitate water absorption.
• How are xylem cells adapted to their function?

  • No margins between cells for continuous water flow.
  • Thick, woody side walls strengthen structure and prevent collapse.
• How are phloem cells adapted to their function?

  • Sieve plates allow transport of dissolved substances.
  • Companion cells provide energy for active transport.
• What is cell differentiation?

  The process by which cells become specialized.
• Why is cell differentiation important?

  It allows the production of different tissues and organs that perform various vital functions in the human body.
• At what point in their life cycle do most animal cells differentiate?

  Early in their life cycle.
• For how long do plant cells retain the ability to differentiate?

  Throughout their entire life cycle.
• What is the purpose of cell division in mature animals?

  Repair and replacement of cells.
• What are the vital functions performed by cells in the human body?

  Cells perform various vital functions in the human body.
• What is the purpose of cell division in mature animals?

  The purpose of cell division in mature animals is for repair and replacement of cells.
• What changes does a cell undergo as it differentiates?

  A cell becomes specialized through the acquisition of different sub-cellular structures to enable a specific function.
• How is magnification defined?

  Magnification is the number of times bigger an image appears compared to the size of the real object.
• How is resolution defined?

  Resolution is the smallest distance between two objects that can be distinguished.
• How does a light microscope work?

  A light microscope works by passing a beam of light through a specimen which travels through the eyepiece lens, allowing the specimen to be observed.
• What are the advantages of light microscopes?

  • Inexpensive
  • Easy to use
  • Portable
  • Observe both dead and living specimens