Cells

Cards (62)

  • magnification = size of image ÷ size of real object
  • Total Magnification = magnification of eyepiece x objective lens
  • resolution is the ability to distinguish two objects that are close together, or two objects that are far apart
  • electron microscope can magify up to 2 million times and can see sub-cellular structures
  • plant cell, cellulose wall is the outer layer, rigid, keeps the wall in shape
  • plant cell, large permanent vacuole, stores water, sugar and minerals, plant support
  • plant cell, chloroplasts, contain green chemical chlorophyll, which absorbs light energy for photosynthesis
  • Mitochondrion, found in cells cytoplasm that are the site of respiration, they release energy
  • Nucleus, controls cell, contains chromosomes that carry genes that control characteristics
  • Nuclear membrane, surrounds nucleus, contains pores to allow substances to move between nucleus and cytoplasm
  • cell membrane, controls what enters and leaves the cell
  • cytoplasm, jelly-like substance where most chemical reactions occur, keeps cell alive
  • Bacteria Cells, capsule, for defence against invading viruses
  • bacteria cells, non-cellulose cell wall, made from protein and carbohydrates
  • bacteria cell, plasmid, additional loop of DNA
  • bacteria cell, mesosome, for chemical reactions e.g. respiration
  • specialised cells and differentiated to do different jobs
  • Leaf palisade cell makes sugar, lots of them + cylindrical shape to pack tightly, on upper surface of leaves
  • Root hair cell, absorbs water + minerals from soil, long to increase surface area to absorb easier, at tip of plant root
  • sperm cell, male sex cell that fertilises egg, swims using flagellum, has many mitochondria to release energy for movement, half normal chromosomes, produced in testes
  • red blood cells, carry oxygen and haemoglobin around the body, biconcave disc to increase surface area for gas diffusion, no nucleus to hold more oxygen
  • nerve cell, carries nerve impulses, long nerve fibre to reach other cells, covered in myelin to speed up transmission of impulses, found in all parts of the body
  • ciliated epithelial cell, cells that line the bronchioles, use cilia to move mucus upwards towards the trachea
  • digestive system is the process of breaking down food into smaller molecules for absorption, mouth, stomach, intestines
  • respiratory system is the exchange of gases between the body and the environment, oxygen exchanges with CO2, trachea, bronchi, lungs
  • circulatory system is the transportation of materials around the body by the blood, heat and protection, heart, blood vessels
  • skeletal system is for support, protection and movement, ribs, backbone
  • excretory system is getting rid of toxic waste, liver, kidneys, bladder
  • reproductive system is the production of gametes and fertilisation, testes, ovaries
  • sensory system is touch, taste, smell, hearing, and vision, skin tongue nose ears eyes
  • nervous system is the response to stimuli and coordination, brain, spinal cord, nerves
  • tissue is a similar group of cells
  • organs are different tissues working together to do a particular job
  • organ systems are a collection of organs working together
  • an organism is a collection of organ systems that can carry out all characteristics of life
  • unicellular organisms exchange through the cell-surface membrane
  • multicellular organisms have cells that are not in direct contact with the surrounding enviornment
  • multicellular organisms have specialised exchange surfaces, have more complex transport system links
  • rate of exchange depends on organisms surface area that is in contact with the surroundings
  • As an organism increases in size the surface area to volume ratio decreases