Biology Module 1

what are the types of cells?

prokaryotic: primitive, simple

• bacteria, archaea

eukaryotic: more evolved

• animal, plant, fungi, protista

describe prokaryotic cells

• 0.1-0.5 micrometres

• no nucleus; no membrane surrounding genetic material

• most genetic material forms large loop called bacterial chromosome

  • rest in small circular rings called plasmids

what are the main structures of prokaryotic cells?

• cell membrane

• cytoplasm

• ribosomes

• genetic material → in large loop called nucleoid

the structures inside prokaryotes:

• nucleoid

• DNA is a single loop

• not surrounded by membranes

• float around in fluid-like cytoplasm

structures present only in some prokaryotes?

• cell wall

• pili

• flagella

• capsule

describe eukaryotic cells

• 10-100 micrometres

• characterised by membrane-bound nucleus containing genetic material

• internal structures are membrane-bound organelles

• both unicellular & multicellular

what are the main structures of eukaryotic cells?

• double-membrane-bound nucleus

• mitochondria

• golgi apparatus

• chloroplasts

what are the structures common to both prokaryotic & eukaryotic cells?

• ribosomes

• cell membrane

• cytoplasm

• genetic material

draw a prokaryotic cell

label the diagram of a prokaryotic cell

draw a eukaryotic cell

label the diagram of a eukaryotic cell

classify the prokaryotes (groups)

bacteria

• cyanobacteria

  • stromatiles

• nitrogen fixing bacteria

archaea

• methanogens

• thermophiles

• halophiles

• deep sea bacteria

why is methane an increasing threat to environment?

increases more rapidly than any other gas

where are methanogens found?

marine & freshwater sediments, intestinal tracts of herbivores (e.g. cows), sewage treatment facilities

what is methane produced by?

methanogens

how do microorganisms produce methane?

from other gas present during fermentation

• methanogens are anaerobic

• methanogens use H2, S & CO2 in inorganic reactions for growth & chemical energy

• produces CH4 in process

where are halophiles found? give an example

environments where salt concentration is very high (e.g. Dead Sea in Middle East) & evaporating ponds of saline water

what eats halophiles?

filter feeders

are halophiles aerobic or anaerobic?

all aerobic but have another system of producing energy

what is the red colour in halophiles caused by?

unique pigment called bacteriorhodopsin

• enables them to photosynthesise & produce energy without using oxygen

what do thermophiles need for growth?

high temperatures (80-105C)

where are thermophiles found? give examples

areas of volcanic activity

• e.g. hot springs, geysers, hydrothermal vents/cracks in ocean floor

what are thermophiles also called?

ones that live in hydrothermal vents in depths of ocean sometimes called deep-sea bacteria

what do thermophiles use sulfur for?

energy source

what are thermophiles in deep-sea food web?

primary producers (chemoautotrophs)

where is deep sea bacteria found?

bioling undersea vents of volcanoes

what are deep sea bacteria in food webs?

basis of food web in undersea vents

how do deep sea bacteria obtain energy?

uses sulfur compounds from volcanoes

where do cynaobacteria live & with what?

marine environment

• some free living, some exist in association with fungi (mutualism)

where do ancient forms of cyanobacteria exist?

in stromatolites

what is cyanobacteria also known as & why?

blue-green algae because they are aquatic & photosynthesise

what do cyanobacteria do for the soil?

many fix nitrogen thus enriching soil they live in

how are stromatolites formed?

water colonies of cyanobacteria trap calcium carbonate & grow upwards in columns towards the sun

where can people visit to see stromatolites?

Western Australia at Shark Bay

what is the growth rate of stromatolites?

• 1mm per year

• diameter of 200cm

• height of 50cm

where are nitrogen fixing (changing) bacteria found?

nodules living on roots of legume (pea plants) plants or in soil

what do nitrogen fixing bacteria do?

convert:

nitrogen gas from atmosphere → ammonium ions → amino acids in plants → plants grow in low-nitrogen soil

label the nitrogen cycle

where is bacteria found & what can they be?

in all types of environments, harmful/beneficial

where is archaea found? give examples

in extreme harsh environments e.g.:

• hot springs

• very salty lakes

• depe thermal vents of volcanoes

• sewage lagoons

• intestinal tracts of animals

what do some organisms develop & why?

• develop strategies to survive harsh conditions

• allows bacteria to be the most abundant life form in terrestrial & land ecosystem

what do almost all prokaryotes have?

cell wall

• protective structure for survival in hyper- & hypo-osmotic coniditons

what do some soil bacteria form?

• endospores that resist heat & drought

• allows survival until favourable conditions recur

what is the Dead Sea & where is it located?

hypersaline basin located between Joran & Israel

what is the concentrations of the Dead Sea?

• salt concentration 10 times higher than seawater

• magnesium 40 times higher than seawater (toxic to most organisms)

what produces “hard” water?

elements that form divalent ions:

• iron (Fe2+)

• calcium (Ca2+)

• magnesium (Mg2+)

what makes the Dead Sea unique & hostile?

high concentration of dilavent cations, acidic pH (6.0), intense solar radiation together

classify the kingdoms of eukaryotes

• plant

  • algae

  • ferns

  • conifers

  • flowering plants

• animal

  • invertebrates (i.e. worms, insects)

  • vertebraes (fish, amphibians, reptiles, birds, mammals)

• fungi

  • mushrooms

  • yeast

• protist

  • amoeba

  • paramecium

  • euglena

draw a eukaryotic plant cell

label the diagram of a eukaryotic plant cell

draw a eukaryotic animal cell

label the diagram of an animal cell

identify, draw, label

identify, draw, label

label the light microscope

function of the eye piece (barrel)

holds ocular lens

function of revolving nose piece

can be moved to change lenses

function of lens

magnifies samples/specimen

function of stage

holds sample

function of stage clip

holds slide in place

function of diaphragm

adjust light

function of light source

provides light

function of arm + base

holds microscope

function of focus knob

for resolution

what are the FOV’s of each lens on the microscope?

• 4x: 4.5mm or 4500 micrometres

• 10x: 1.8mm or 1800 micrometres

• 40x: 0.45mm or 450 micrometres

• 100x: 0.00018mm or 0.18 micrometres

• 400x: 0.000045mm or 0.045 micrometres

what is the proper procedure for using a light microscope?

1. Plug in microscope & turn on

2. Lower stage to lowest level using coarse focus knob

3. Turn revolving nosepiece until 4x lens (lowest magnification)

4. Put lens under stage at its highest position & adjust iris diaphragm

5. Prepare wet mount/slide

6. Place specimen slide on stage & centre it

7. Look through eyepiece & turn coarse focus knob until blurry image

8. Make image clearer using fine focus knob

9. Turn to 10x lens & only use fine focus knob

10. Draw scientific diagram of sample

define resolution

ability to see detail

define magnification

ability to make objects appear larger

how to calculate total magnification?

eyepiece mag x lens mag

what are the types of microscopes?

light & electron

what was discovered using the microscope?

cells & their structure

how do light microscopes work?

passing light through specimen & magnify light using lenses

how do electron microscope work?

passing beams of electrons through specimens & detect electrons by sensors which projects image onto screen

what organelles are visible with light microscope & which ones need staining?

• nucleus (can be stained)

• cytoplasm (needs staining)

• cell wall

• chloroplasts

• vacuole

what organelles are visibe with electron microscope & which ones need staining?

• cell membrane (needs staining)

• cell wall

• golgi (needs staining)

• chloroplast

• mitochondria

• ER (needs staining)

• ribosome

• lysosome

• cytoplasm (needs staining)

• centrosome

• cytoskeleton (needs staining)

identify the process of the development of the cell theory, include who & what year

roger bacon, 13th century → leonardo da vinci, 1485 → hans & zacharias janssen, circa 1600 → robert hook, 1665 → marcello malpighi, 1672 → anton van leeuwenhoek, 1676 → rene dutrochet, 1824 → robert brown, 1831 → matthias schleiden & theodore schwann, 1839 → rudolf virchow, 1858 → louis pasteur, 1862 → walter flemming, 1880-1882 → ernest ruska & max knoll, 1933

describe the ‘microscope’ & significance of Roger Bacon including what year

• 13th century

• used convex lenses as magnifying glass

• first to describe properties of convex lenses, hence inventor

describe the ‘microscope’ & significance of Leonardo Da Vinci including what year

• 1485

• used glass lenses

• 1508: described & sketched first ideas for contact lenses

describe the ‘microscope’ & significance of Hans & Zacharias Janssen including what year

• circa 1600

• developed first compound microscope

• used convex objective & concave eyepiece to enlarge

describe the ‘microscope’ of Robert Hooke including what year

• 1665

• used bi-complex objective lens placed in the snout & two additional lenses, an eyepiece lens, a tube/field lens

what did Robert Hooke discover & in what year?

1665, discovered plant cells (more specific, the cell walls in cork tissue)

why did Robert Hooke call cells cells?

box-like cells of cork reminded him of cells in monastery

what did Robert Hooke report?

seeing structures in wood & other plants

describe the significance (what he discovered) of the microscope & Marcello Malpighi Including what year

• 1672

• stated all plants built of chambers

• credited with using microscope as a tool in organism study

• founder of histology (study of tissue under microscope)

• investigated microscopic anatomy of human body

• discovered relationships of capillaries, veins, arteries

• took tissues of tongue & discovered taste buds

describe the significance of the microscope & Anton van Leeuwenhoek including what years

• 1676: first encounter with microscopy: examining cloth samples with magnifying glass

• 1683: discovered bacteria from observation of saliva

describe the significance of Rene Dutrochet including what years

• 1863: discovered & named osmosis

• 1824

  • studied development of bird eggs

  • recognised the take-up of carbon dioxide by plant cells depended on their green pigment

  • stated all organisms are made of cells

describe the significance of Rober Brown including what year

• 1824

• observed fertilisation mechanisms of plants

• noted existence of a structure within cells of orchids

• termed the “nucles” of cells

describe the significance of Matthias Schleiden & Theodore Schwann including what year

• 1839

• proposed all organisms are made of cells

• formulated early cell theory

• Schwann discovered cells (Schwann cells)

  • forms sheath surrounding nerve axons

• conducted experiments that helped disprove theory of spontaneous generation

• coined “metabolism” to define chemical changes that take place in cells

• demonstrated that yeast organisms cause fermentation of sugar solutions

describe the significance of Rudolf Virchow including what year

• 1858

• “all cells arise from pre-existing cells”

• rejected spontaneous creation of cells from non-living matter

describe the significance of Louis Pasteur including what year

• 1862

• provided proof of Rudolf’s idea with classic swan neck flash experiment

describe the significance of Walter Flemming including what year

• 1880-1882

• observed chromosomes during animal cell division

• first to detail how chromosomes move during cell division

• described whole process of mitosis (prophase, metaphase, anaphase)

describe the significance of Ernst Ruska & Max Knoll including what year

• 1933

• created Transmission Electron Microscope

draw the flow chart of technologies used to view cells

describe the different types of microscopes in terms of their magnification, resolution, advantage, disadvatage, how image is produced

define organelles & their function

• identifiable bodies in cell

• surrounded by membrane

• specific functions within cell

  • carry out biochemical processes & reactions (e.g. photosynthesis, respiration

function of nucleus

contains genetic material

how big is a nucleus?

2-10 microns

what happens when nucleus is about to divide

chromatin arranges into chromosomes

identify & label the organelle