bio paper 1

• What is cell differentiation?

  the process by which unspecialized cells develop into their mature forms and functions
• What is a eukaryotic cell?


  Cell with a nucleus and membrane bound organelles

  
• What is a prokaryotic cell?


  cell that does not have a nucleus or membrane bound organelles

  
• What are the Differences and similarities between Prokaryotic and Eukaryotic cells

  Eukaryotic contain a nucleus and Prokaryotic dont

  Eukaryotic= 10-100hm (micro)

  Prokaryotic = 0.1 - 10 hm (micro)See an expert-written answer!We have an expert-written solution to this problem!

  
• what does the word centi mean?


  "centi" means 1/100th (of a metre) so 1m = 100 cm

  1 x 10^-2 m
• What does the word milli mean?


  It means 1/1000th ( of a metre) so 1cm = 10mm

  1 x 10^-3 m
• What does the word micro mean?


  It mean 1 millionth (of a metre)

  1 hm = 1 x 10^-6 m

  used to measure cells

  
• What does the word nano mean?

  It means 1 000 000 000 th (of a metre )

  1nm= 1 x 10^-9

  used to measure proteins in cells such a hemoglobin

  
• What is the Order of Magnitude?


  A way of comparing sizes of objects

  EG. each order of magnitude is increased by x10

  x10 = 1 O of M x100 = 2 O of M

  
• ANIMAL AND PLANT: What is the function of the nucleus?

  contains the cell's genetic material (DNA)

  
• ANIMAL AND PLANT :What is the function of the Cytoplasm?

  Where chemical reactions take place

  
• ANIMAL AND PLANT: What is the function of the mitochondria?

  Where cellular Aerobic respiration takes place

  
• ANIMAL AND PLANT: What is the function of the cell membrane?

  The cell membrane regulates what enters and leaves the cell and also protects and supports the cell.

  
• ANIMAL AND PLANT: What is the function of Ribosomes?

  The site of protein synthesis, where new proteins are made.

  
• PLANT: what is the function of chloroplasts?

  Contain chlorophyll , allows photosynthesis.

  
• PLANT: what is the function of the cell wall?


  Made from cellulose, strengthens the cell

  
• PLANT: what is the function of the Vacuole?

  Filled with cell sap. Help keeps the cell in its shape.

  
• What is differentiation?


  The process by which a cell changes to become specialised for its job
• What are examples of unspecialised cells?

  Stem cells
• Animal: What are sperm cells and how are they specialised?/adapted?

  -Sperm cells aid in reproduction, they pass on the fathers DNA so it can pair with mother DNA in the ovum

  -Sperm contains half the amount of chromosomes in nucleus.

  - They have a long tail that rotates which allows it to swim

  - contain many mitochondria so provides alot of energy

  - the head contains enzymes to digest the the outer layer of ovum and allow the sperm to enter

  
• Animal: What are nerve cells and how are they specialised ?/adapted?


  -Nerve cells send electrical signals around body

  - Long axon (body) so it can carry energy over a longer distance

  - A material called Myelin insulates Axon , speeds up transmission of impulses

  -End of Axon have synapses, allows to connect to other nerve cells

  
• Animal: What are muscle cells and how are they specialised?/ adapted?


  -Muscles cells contract and allow movement

  -Muscle cells can contract ( get shorter) due to protein fibers that can change length

  - they packed of mitochondria to provide energy for contraction

  -form muscle tissue to work together efficiently

  
• Plant: What are root hair cells and how are they specialised/ adapted?


  -They absorb water and mineral ions from the soil

  - root hair increases surface area of the root so more water can be taken in via osmosis

  -thinner walls allow water move in more easily

  -Do not contain chloroplasts as they do not have access to light

  
• Plant: What are Xylem cells and how are they specialised?/adapted?


  - They are found in the stem and form hollow tubes that transport water + minerals to leaves via transpiration

  -thick walls containing lignin provide support to plant, causes cells to die so water + minerals can flow easily

  -no nucleus , cytoplasm or chloroplast, makes it easier for nutrients to flow

  
• What are the different parts of the microscope?

  
• Required Practical 1 : using a light microscope

  - how to prepare a slide to look at under the microscope

  1) using a pipette , place one drop of water onto slide

  2)prepare thin layer of plant (onion)

  3) put onto slide and dye with two drops of iodine so cellular structures visible

  4)put coverslip over the slide

  5) place onto stage of microscope , clip it down

  
• Required Practical 1: using a light microscope

  - how to use a microscope with a prepared slide


  1)turn nosepiece to the lowest setting

  2) looking from the side, turn coarse adjustment knob so that the end of the lense is almost touching slide

  3) looking through eyepiece, turn the adjustment knob to increase distance again until cells come into focus

  4)rotate fine adjustment knob to bring the cells into clear focus and use low power objective to look at cells

  5) when found cells, switch to higher power objective (x100 or x400)

  6)
• Required Practical 1: Using a light microscope

  Observing drawing conclusions

  1) Draw what you see under the microscope using a pencil with a sharp point

  2) Make sure your drawing takes up at least half of the space available & that it is drawn with clear, unbroken lines

  3) Your drawing should not include any colouring or shading

  4) If you are drawing cells, the subcellular structures should be drawn in proportion

  5) Include a title & write down the magnification that it was observed under

  6) Label the important features of your drawing using straight, uncrossed lines
• What are the disadvantages of light microscopes?


  limited magnification and limited resolution

  
• Advantages of an electron microscope

  higher resolution (0.2nm)

  better magnification

  
• What are the sub-cellular structures of an animal cell?


  -A nucleus

  -Cytoplasm

  -Cell membrane

  -Mitochondria

  -Ribosomes
• What is the formula for magnification?

  Magnification = image size / real size

  
• What are the sub-cellular structures of a plant cell?

  -A nucleus

  -Cytoplasm

  -Cell membrane

  -Mitochondria

  -Ribosomes

  -Cell wall

  -Permanent Vacuole

  -Chloroplasts
• What is the formula for the size of the image?


  Size of image= magnification x size of real object

  
• What is a nucleus?


  A nucleus controls the activities of the cell and contains the genetic material
• What is binary fission?


  (Asexual)A type of simple cell division used by prokaryotic cells to reproduce & split into two

  
• What is cytoplasm?


  Cytoplasm is where the majority of chemical reactions take place
• What happens during binary fission?


  1) The circular DNA & plasmid(s) replicate

  2) The cell gets bigger & the circular DNA strands move to opposite poles of the cell

  3) The cytoplasm begins to divide & new cell walls begin to form

  4) The cytoplasm divides & two daughter cells are produced. Each daughter cell has one copy of the circular DNA, but can have a variable number of copies of the plasmid(s)

  
• What is a cell membrane?

  A cell membrane controls the passage of substances into and out of the cell
• What conditions do bacteria need to divide by binary fission?

  bacteria can divide once every 20 minutes as long as they have:

  A warm environment

  Lots of nutrients