P1 - SUMMARY

• What are the main topics covered in Edexcel GCSE Biology Paper 1?

  Cells, control, genetics, natural selection, health
• What is the difference between eukaryotic and prokaryotic cells?

  Eukaryotic cells have a nucleus; prokaryotic do not
• What is the function of the cell membrane?

  It keeps everything inside the cell
• What is the role of mitochondria in a cell?

  They release energy through respiration
• What is the function of ribosomes?

  They assemble proteins
• What is the role of chloroplasts in plant cells?

  They conduct photosynthesis
• What is the enzyme amylase responsible for?

  Breaking down starch into glucose
• How do enzymes work according to the lock and key model?

  The substrate fits into the enzyme's active site
• What happens to an enzyme when it denatures?

  The active site changes shape, preventing binding
• What is the optimum temperature for enzyme activity?

  The temperature at which the enzyme works best
• What color does iodine turn in the presence of starch?

  Black
• What is diffusion?

  Movement of molecules from high to low concentration
• What is osmosis specifically?

  Diffusion of water across a membrane
• How can the rate of diffusion be increased?

  By increasing concentration difference, temperature, or surface area
• What is active transport?

  Movement of substances against a concentration gradient
• What is the process of mitosis?

  Cell division producing two identical cells
• What are stem cells?

  Cells that haven't specialized yet
• What is the role of the central nervous system (CNS)?

  It processes information and coordinates responses
• What is a reflex arc?

  A pathway for reflex actions bypassing the brain
• What is the function of the medulla oblongata?

  Controls unconscious actions like heart rate
• What is myopia?

  Shortsightedness
• How does laser eye surgery correct vision?

  By changing the shape of the cornea
• What is meiosis?

  Cell division producing gametes
• What is the advantage of sexual reproduction?

  It increases genetic variation in offspring
• What is the difference between genotype and phenotype?

  Genotype is genetic code; phenotype is expression
• What is the Human Genome Project?

  It mapped all human genes and their functions
• What are nucleotides?

  Monomers that make up DNA strands
• How are amino acids coded in DNA?

  Every three bases code for one amino acid
• What happens when a harmful mutation occurs in a gene?

  A protein may be synthesized incorrectly
• What term is given to the code stored in DNA?

  Genotype
• How is phenotype defined?

  It is how genotype is expressed in characteristics
• What are the monomers between DNA strands called?

  Nucleotides
• What are nucleotides made from?

  A sugar and phosphate group
• How many types of nucleotides are there?

  Four types: A, T, C, and G
• Which nucleotide pairs with adenine?

  Thymine
• Which nucleotide pairs with cytosine?

  Guanine
• What do three bases in DNA code for?

  An amino acid
• What is the role of mRNA in protein synthesis?

  It copies the DNA sequence
• Where does mRNA take the copied sequence?

  To a ribosome in the cell
• What must happen to proteins for them to function properly?

  They need to be folded