Biology HL Skills from IB1

  • Created by: Foxic
  • Created on: 07-05-15 09:45

1.1 Drawing cell structures as seen with the light

  • Sharp pencil
  • Join up lines carefully
  • Draw lines freehand
  • Use a ruler for labelling lines
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1.1 Calculation of magnification and actual size

  • Can be measured in millimetres (mm) or micrometres (μm)
  • 1 millimetre = 1000μm    
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1.2 Draw the ultrastructure of prokaryotic cells f

  • Include free ribosomes, cell wall, plasma membrane (peptidoglycan), cytoplasm, nucleoid (region containing naked DNA), and pilli/flagella if applicable
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1.2 Draw the ultrastructure of eukaryotic cells fr

  • Nucleus (double nuclear membrane, nuclear pores, densely staining chromatin)
  • Rough endoplasmic reticulum (ribosomes on cisternae)
  • Golgi apparatus (cisternae with vesicles surrounding it)
  • Lysosome (digestive enzymes, single lisosome membrane)
  • Mitochondrion (outer membrane, inner membrane forming crista, filled with matrix)
  • Free ribosomes
  • Chloroplast (contains double membrane, thylakoid, stroma, and starch grain)
  • Vacuoles and vesicles (size depends on function. Plant cell has a large central vacuole, animal cells have several smaller ones)
  • Microtubules and microtubules (looks like an "i")
  • Cilia and flagella (used for locomotion, many cilia, usually 1-2 flagella)
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1.2 Interpreting the structure of eukaryotic cells

  • Identify organelles and deduce function
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1.3 Drawing the fluid mosaic model

  • Show phospholipids, integral proteins, peripheral proteins, and cholesterol
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1.3 Evidence for and against Davson-Danielli model

  • Davson-Danielli model:Layers of protein adjacent to membrane on both sides
  • For: EM showing "sandwich layers" of protein on either side of membrane
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1.3 Evidence for Singer-Nicholson model

The Davson Danielli model was disproved by this evidence:

  • Freeze-etched EM's (cells frozen and fractured, showing transmembrane proteins), structure of membrane proteins (proteins extracted in many shapes, unlikely to form layers, were also hydrophobic), fluorescent antibody tagging (showed fluidity of membrane)

This led to the Singer-Nicholson model which stated that proteins are able to move, and integral proteins and their positions are like mosaic tiles, hence the term "fluid mosaic model

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1.4 Estimation of osmolarity in hypo/hypertonic so

Can estimate osmolarity by measuring whether water enters/leaves tissue. 

Deduce what it is isotonic to, and therefore estimate osmolarity.

  • Hypotonic => water enters the cell making it become turgid (plant) or to lyse (animal cell)
  • Hypertonic => water leaves the cell making it plasmolysed (plant) or to shrivel forming "red blood cell ghosts (animal cell)
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2.1 Draw glucose/ribose/sat fatty acid/amino acid

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2.1 Identification carbs, lipid, proteins from dia

  • Proteins: C, H, O, N, S
  • Carbohydrates: Contain H and O atoms in a 2:1 ratio. Contain C, H, O.
  • Lipids: Contain less relatively less O than carbohydrates. Contain C. H, O.
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2.3 Determination of BMI by calculation/monogram

  • For monogram see textbook p.81
  • BMI
  • Underweight: Below 18.5
  • Normal weight: 18.5-24.9
  • Overweight: 25.0-29.9
  • Obese: 30.0 or more
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2.4 Draw molecular diagrams that show formation of

  • Two a.a. linked by a condensation reaction between the amine group of one and the carboxyl group of the other
  • There is a chain of atoms liked by single bonds -N-C-C-
  • H atom linked by single bond to each N atom in backbone
  • O atom linked by double bond to one of C atoms
  • Amine and carboxyl groups remain at the ends of the chain
  • R groups of each a.a. remain and project out from backbone
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6.1 Production and annotation of the digestive sys

  • Mouth: voluntary eating and swallowing. Mechanical digestion (chewing). Chemical digestion by mixing with saliva, which contains lubricants and enzymes to starch digestion
  • Esophagus: Movement of food by peristalisis from the mouth to the stomach
  • Stomach: Mechanical digestion (churning) to kill pathogens, and to begin protein digestion
  • Small intestine: Final stages of digestion of lipids, carbohydrates, proteins, nucleic acids. Neutralize stomach acid. Absorption
  • Pancreas: Secretion of lipase, amylase, and protease
  • Liver: Secretion of surfactants in bile to break up liquid droplets
  • Gall bladder: Storage and regulated release of bile
  • Large intestine: Re-absorption of water, further digestion by symbiotic bacteria, formation and storage of feces.
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6.1 Tissue layers in transverse section small inte

From outside:

Serosa, longitudinal muscle, circular muscle, sub mucosa, mucosa

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6.2 Identify arteries/capillaries/veins from struc

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Recognition of the chambers, valves, blood vessels

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6.5 Analysis of oscilloscope traces showing restin

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6.6 Annotate diagrams of male/female reproductive

Need to annotate and label the..

  • Female: Ovary, oviduct, uterus, cervix, vagina, and *****
  • Male: Testis, scrotum, epididymis, sperm duct, seminal vesicle and prostate gland, urethra, and penis
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8.1 Distinguish different types of inhibition from

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6.4 Calculating rates of reaction

  • Measure rate of disappearance of substrate or rate of appearance of product
  • Sometimes need to require conversion of units to yield a rate unit what should include 
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11.2 Annotate diagram of human elbow


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11.2 Draw labelled diagram of sarcomere structure

  • Show that there are 2-lines, myosin filaments with heads, actin filaments should be shown connected to Z-line, light and dark bands (extent) should be indicated
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11.2 Analysis of EMs to find state of contraction


  • Z-lines are farther apart
  • Light bands are wider
  • Sarcomere is longer
  • More visible light band on either side of the M-line 



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11.4 Annotate diagrams of seminiferous tubule and

  • Seminiferous tubule:Germinal epithelium cells, basement membrane, spermatogonium, primary spermatocytes, secondary spermatocytes, spermatids, Sertoli cells, sperm
  • Ovary: Secondary follicle, oocyte, developing follicles, primary follicles, degenerating, corpus luteum, and developing, ovulated ovum, mature follicle
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11.4 Annotate diagrams of mature sperm and egg

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