B1 - cell biology

• Name 5 subcellular structures that both plant and animal cells have?

  Nucleus

  Cytoplasm

  Cell membrane

  Mitochondria

  Ribosomes
• What 3 things do plant cells have that animal cells don't?

  Cell wall

  Vacuole

  Chloroplasts
• Where is the genetic material found in animal cells?

  Nucleus
• Where is the genetic material found in bacterial cells?

  They don't have a "true" nucleus - instead, they have a single circular strand of DNA that floats in the cytoplasm
• Are bacteria prokaryotes or eukaryotes?

  Prokaryotes
• Which gives a higher resolution a light microscope or an electron microscope?

  Electron microscope
• What is cell differentiation?

  The process in which cells become specialised in structure and function.
• Give 3 ways that a sperm cell is adapted for swimming?

  Flagellum

  Streamline shape

  Has lots of mitochondria
• What shape are nerve cells?

  Long

  Branching

  
• What are chromosomes?

  Thread-like structures made of DNA and proteins that carry genetic information in the form of genes.
• What is the cell cycle?

  The events that take place in a cell leading to its division and duplication.
• What is mitosis used for by multicellular organisms?

  Growth and repair
• Give 2 ways that embryonic stem cells can be used to cure diseases?

  Can turn into any type of cell

  Can be grown in labs to differentiate into specialised cells to use in medicine/research
• Why might some people be opposed to the use of human embryos in stem cell research?

  Ethical reasons/concerns
• What is diffusion?

  Movement of particles from an area of high concentration to an area of low concentration.
• Name 3 substances that can diffuse through cell membranes?

  Oxygen

  Carbon dioxide

  Water
• Name 2 substances that can't diffuse through cell membranes?

  Large molecules

  Ions
• What type of molecules move by osmosis?

  Water molecules
• Give 2 differences between active transport & diffusion?

  Diffusion is high - low concentration

  Active transport is low - high concentration.

  This means active transport goes against the concentration gradient
• Give 3 adaptations of exchange surfaces that increase the efficiency of diffusion?

  Increased surface area

  Thin membrane

  Good blood supply
• Give 2 ways that the villi in the small intestine are adapted for absorbing digested food?

  Increased surface area

  Rich blood supply
• Explain how leaves are adapted to maximise the amount of carbon dioxide that gets to their cells?

  They are thin and flat so the carbon dioxide has a shorter distance to diffuse and the diffusion is faster