B2 - Cells / Organisation of the Organism Flashcards
What is the cell theory? (3)
(Not specified in syllabus but still important)
1) All organisms are composed of one or more cells
2) The cell is the basic organizational unit of life
3) All cells arise from pre-existing cells
Animal cells
Cell membrane (2)
(In plants & bacterial cells, still has same function)
1) Separates the interior of the cell from the environment outside
2) Controls which substances can enter / leave the cell - selectively permeable
Animal cells
Nucleus (2)
(In plants as well & has same function)
1) Controls all cell activity
2) Contains the genetic material (DNA)
Nucleus can also be called control unit of a cell
Animal cell
Cytoplasm (2)
(In plants & bacterail cells, still has same function)
1) Gel like substance inside the cell which contain the organelles (cell structure)
2) Site of chemical reactions
Animal cells
Ribosomes (1)
(In plants & bacterial cells, still has same function)
1) Site of protein synthesis
In bacterial cells they are smaller (70S - Humans = 80S)
S = Svedberg unit (extra knowledge)
Animal cells
Mitochondria (2)
(In plants as well & has same function)
1) Site of respiration
2) Provides energy for cell to function
Plant cells (only)
Vacuole (2)
1) Keeps the cell firm (turgid) to support plant
2) Contains or stores salts and sugars
Vacule is a fluid filled sac
Contains amino acids, waste, pigment (extra knowledge)
Plant cells (only)
Chloroplasts (2)
1) Site of photosynthesis, where is makes glucose sugar
2) Contains green pigment which absorbs light energy for photosynthesis
Photosynthesis equation =
6CO2 + 6H2O → C6H12O6 + 6O2
Plant cells
Cell wall (3)
(In bacterial cells as well)
1) Fully permeable (something such as water or gas can pass through it or soak into it)
2) Support and protects the cell (stops it from bursting)
3) Made of cellulose
Bacterial cells (only)
Circular DNA (2)
Instead of nucleus it has ↑↑↑
1) Contains the genetic material
2) Controls the cell
Bacterial cells
Cell wall
Has same function as plant cell but is made out of something different
1) Fully permeable (something such as water or gas can pass through it or soak into it)
2) Made of peptidoglycans (contains protein)
Bacterial cells (only)
Plasmid (1)
1) Circular rings of DNA containing survival genes, which can be transferred to other bacteria
Bacterial cells
What structure does a bacterial cell lack? (3)
1) Nucleus
2) Mitochondria
↑↑↑ can be used when comparing with animal & plant cells
3) Chloroplasts (comparing with plants only)
B2.1.1
Compare a plant & animal cell (10)
YOU DO NOT NEED TO KNOW ALL TEN!!!!
5 similarities & 5 differences
Similarities : both contain a nucleus, cytoplasm, mitochondria, ribosomes and a cell membrane.
Differences : plant cells contain chloroplasts, cell wall, & vacuole. Plants have a more regular shape (rectangular) & are larger
B2.1.5
How are new cells produced? (1)
This will be further discussed in B17 - Inheritance
By the divison of existing cells
Specialised cells
Ciliated cells (3)
1) Found in the lining of the trachea
2) Have tiny hair like structure (cilia)
3) Cillia move together to transport mucus, dust, & bacteria out of the airways
Specialised cells
Root hair cells (3)
1) No chloroplasts
2) Have larger surface area for better absorbtion of water & minerals
3) Thin walls for water & mineral ions to move through quickly for faster osmosis
4) Cell wall is partially permeable membrane
Specialised cells
Palisade Mesophyll cell (4)
This will be further discussed in B6 - Plant nutrition
1) Many chloroplasts
2) Contain chlorophyll & enzymes necessary for production of glucose
3) Cell wall provides structural support protects against damage
4) Fully permeable
Specialised cells
Neurons (6)
This will be further discussed in B14 - Coordination & response
1) Transmits electrical impulses
2) Cells are myelinated which insulates it (prevents the impulse weakening & slowing down)
3) Lots of mitochondria for energy
4) Dendrites have large surface area
5) Communicate with other cells
6) Branched out to receieve impulsues from other neurons
Specialised cells
Red Blood cells (3)
This will be further discussed in B9 - Transport in animals
1) Contains haemoglobin (carries oxygen)
2) Biconcave shape (increased surface area)
3) No nucleus
Specialised cells
Sperm cells (4)
This will be further discussed in B16 - Reproduction
maybe B17 - Inheritance
1) Contains gametes
2) Lots of mitochondria for energy
3) Tail (flagellum) for movement
4) Contains digestive enzymes
Gametes are an organism’s reproductive cells (haploid)
Specialised cells
Egg cells (3)
This will be further discussed in B16 - Reproduction
maybe B17 - Inheritance
1) Contains gametes
2) Membrane prevents more than 1 sperm from entering
3) Contains cytoplasm with nutrients for embryo
Gametes are an organism’s reproductive cells (haploid)
B2.1.7
What is a cell? (2)
The basic structural units of a living organism
Ex: guard cells (plant) , neurone (animal)
B2.1.7
What is tissue? (2)
Groups of similar cells that work together to perform the same specific function
Ex: palisade mesophyll (plant) , nervous/neurone tissue (animal)
B2.1.7
What is an organ? (2)
Made from different tissues working together to perform specific functions
Ex: flower (plant) , brain (animal)
B2.1.7
What is an organ system? (2)
Groups of organs with related functions working together to perform body functions
Ex: transport system (plant) , nervous system (animal)
B2.1.7
What is an organism? (2)
A complex living thing made of interacting organ system
B2.2.1
Formula for magnification
Rearrange this formula to find what you need to
image size / actual size
Rearrange this formula to find what you need to
M = I/A
B2.2.1
Convert 1mm to micrometers
1mm = 1000µm
1000 µm = 1mm
