Biology Paper 1

• What do animal cells contain?

  Nucleus, cell membrane, cytoplasm, ribosomes, mitochondria
• What is the function of the nucleus in animal cells?

  Stores genetic information
• What is the role of mitochondria in animal cells?

  Release energy in respiration
• What type of cells are animal and plant cells classified as?

  Eukaryotic cells
• What additional structures do plant cells have compared to animal cells?

  Permanent vacuole, chloroplasts, cell wall
• What is the function of chloroplasts in plant cells?

  Contain chlorophyll for photosynthesis
• What is the composition of the cell wall in plant cells?

  Made of cellulose
• What type of cells are bacteria classified as?

  Prokaryotic cells
• What structures do bacteria cells contain?

  Cytoplasm, cell wall, cell membrane
• Where is DNA found in bacteria?

  In a single DNA loop or plasmids
• Why don't bacteria contain mitochondria?

  They would be too large to fit
• How do bacteria and eukaryotic cells differ in terms of nucleus presence?

  Bacteria lack a nucleus; eukaryotic cells have one
• What is the function of specialized cells?

  Adapted structure for specific functions
• How does a sperm cell's structure aid its function?

  It has a tail for movement
• What is the conversion between millimeters and micrometers?

  1 mm = 1000 µm
• What is the formula for magnification?

  Magnification = Image/Object
• What is an order of magnitude?

  Approximate comparisons between numbers
• What does resolution refer to in microscopy?

  Ability to distinguish points close together
• What type of microscope is commonly used in schools?

  Light microscope
• What can light microscopes see?

  Larger cell parts like the nucleus
• Why are electron microscopes considered better than light microscopes?

  Higher resolution and magnification
• What is the first step in observing cells under a microscope?

  Place slide on stage
• Why should you start with the lowest magnification lens?

  It is easier to focus
• What should you do after placing the slide on the stage?

  Switch on the light
• What is the purpose of the focussing knob?

  To bring the image into focus
• What happens if you turn the focussing knob incorrectly?

  You could damage the lens or slide
• What is the overall magnification formula?

  Eyepiece magnification x Objective magnification
• Why must objects be thin to be viewed under a light microscope?

  So light can pass through
• What is cell differentiation?

  Cells become specialized for specific jobs
• What are stem cells?

  Undifferentiated cells
• How do stem cells from human embryos differ from adult stem cells?

  Embryonic stem cells are more versatile
• Where can stem cells differentiate throughout life?

  In many plants
• What is meristem tissue in plants?

  Tissue that can differentiate into any cell
• What are the pros of using embryonic stem cells?

  Can become any type of cell, painless to obtain
• What are the cons of using embryonic stem cells?

  Cannot give consent, death to embryo
• What are the pros of using adult stem cells?

  Patient can give consent, reliable technique
• What are the cons of using adult stem cells?

  Can only treat some diseases, painful procedure
• How can stem cells be used in medicine?

  Treat conditions like paralysis and diabetes
• What is therapeutic cloning?

  Embryo made with same genes as patient
• What is a benefit of using stem cells from embryos?

  Not rejected by patient, can make any cell