PAPER 1 REVISION

• What is the basic unit of life?

  Cell
• What can be seen with a normal light microscope?

  Cells and possibly the nucleus
• What does an electron microscope allow us to see?

  Finer details of organelles
• What is the formula for magnification?

  Magnification = image size / object size
• How do you calculate the actual size of a cell?

  Divide image size by magnification
• What type of cells have a nucleus?

  Eukaryotic cells
• Where is DNA found in prokaryotic cells?

  In a ring called a plasmid and in chromosomal
• What structure keeps everything inside the cell?

  Cell membrane
• What is the function of the cytoplasm?

  It is where most chemical reactions occur
• Where does respiration take place in a cell?

  Mitochondria
• What is the role of ribosomes?

  Assemble or synthesize proteins
• What do chloroplasts contain?

  Chlorophyll for photosynthesis
• What do plant cells contain that animal cells do not?

  Chloroplasts and a permanent vacuole
• How do bacteria multiply?

  By binary fission
• If you start with one bacterium, how many will you have after one hour?

  64 bacteria
• What is the purpose of aseptic technique in culturing bacteria?

  To prevent contamination of the culture
• What is the genome?

  All the genetic material in an organism
• What is a gene?

  A section of DNA coding for a protein
• When was the Human Genome Project completed?

  In 2003
• What is the difference between genotype and phenotype?

  Genotype is the DNA code; phenotype is expression
• What are nucleotides made from?

  A sugar and phosphate group
• How do base pairs match in DNA?

  A pairs with T, C pairs with G
• What is the role of mRNA in protein synthesis?

  It carries the code from DNA to ribosomes
• What happens to proteins after they are synthesized?

  They must be folded to function properly
• What can harmful mutations cause?

  A non-functional protein to be synthesized
• What is epigenetics?

  Influences gene expression without changing DNA
• What are enzymes?

  Biological catalysts
• What does amylase do?

  Breaks down starch into glucose
• What is the lock and key principle in enzymes?

  Substrate fits into the enzyme's active site
• What happens to enzymes at high temperatures?

  They can denature and lose function
• What is aerobic respiration?

  Respiration with oxygen
• What is produced during anaerobic respiration in muscles?

  Lactic acid
• What is oxygen debt?

  More oxygen needed to break down lactic acid
• What do yeast cells produce during anaerobic respiration?

  Ethanol and carbon dioxide
• What is metabolism?

  Sum of all reactions in a cell or organism
• What factors can limit the rate of photosynthesis?

  Temperature, light intensity, CO2 concentration
• How can you measure the rate of photosynthesis?

  By measuring oxygen production over time
• What is diffusion?

  Movement from high concentration low concentration over a concentration gradient
• What is osmosis?

  Diffusion of water from higher water concentration to lower water concentration across a semi membrane
• What is active transport?

  Movement against a concentration gradient using energy