Biology Year 11

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 is the function of organelles? give examples

• have specific functions within cell

• carry out biochemical processes & reactions

  • e.g. photosynthesis, respiration

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?

marine environment

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

where do ancient forms of cyanobacteria exist?

in stromatilites

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

what do water colonies of cyanbacteria do?

trap layers of calcium carbonate & grow upwards in columns towards su

where are stromatolites found?

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

function of nucleus

contains genetic material

how big is a nucleus?

2-10 microns

describe where the genetic information of a eukaryotic cell is

double membrane contains genetic information of the organism, stored in chromatin (DNA would around protein spindles)

what happens when nucleus is about to divide

chromatin arranges into chromosomes

identify & label the organelle

function of mitochondria?

generate chemical energy

describe the inner layer of mitochondria

inner layer highly folded = increases surface area & respiration

how big is mitochondria

0.5-10 microns

function of mitochondria’s outer membrane

lets in small molecules & ions

function of mitochondria’s inner membrane

where ATP synthesises (energy storage molecule for chemical reactions)

how do mitochondria reproduce?

have their own genome & divide by fission

identify & label the organelle

function of chloroplasts

photosynthesis occurs here

function of rought ER

synthesise proteins

what is rought ER made of

made of a single continuous membrane system which can spread across entire cytoplasm

what is rough ER also involved in?

signalling

identify & label the organelle

function of smooth ER

synthesise lipids

function of golgi body

modify & store proteins

how big is golgi body?

0.1-1 microns across

how does golgi body modify proteins?

receive substances from ER → modifies as needed (e.g. attaches carbs) → produces vesicles (carry secretions to cell surface)

give an example of a secretion-releasing organelle in golgi body

epithelial cell: secretes mucous in animals

what happens to cell wall of plants?

exported to outer membrane of golgi bodies

identify & label the organelle

function of lysosomes

break down cellular products

function of vacuole

cellular waste disposal

function of cell wall

provide structure & protection

function of cell membrane

pores allow entry & exit

function of nucleolus

produce ribosomes involved in cell signalling

function of cytoskeleton

give cell shape & help organise cell’s oarts

what is the cytoskeleton made of & what do they provide?

• microtubules, actin filaments, intermediate filaments

• provide basis for movement & cell division