B1 (Cells And Organisms) Flashcards
Eukaryotes
- made up of eukaryotic cells
- complex include animal and plant cells
Prokayotes
- made of prokaryotic cells
- single celled organism
Nucleus
- animal and plant cell
- DNA stored
Cytoplasm
- animal and plant cell
- chemical reactions and enzymes
Cell membrane
- animal and plant cell
- supports cell and controls what goes in and out
Mitochondria
- animal and plant cell
- aerobic respiration to release energy
Ribosomes
- animal and plant cell
- proteins made
Cell Wall
- just plant cells
- contains cellulose, strengthens
Permanent Vacuole
- just plant cells
- contains sap
Chroloplasts
- just plant cells
- contains chlorophyll for photosynthesis and energy
5 differences between Bacteria and Animals/plant cells
- smaller
- no mitochondria
- no chloroplasts
- don’t have true nucleus, DNA floating
- can contain extra DNA
Light Microscopes
- uses light and lenses
- can magnify to see cells and nuclei
Electron microscopes
- higher resolution then light
- uses electrons
- higher magnification
- sees smaller things (ribosomes) in more detail
Magnification=
Image size / real size
0.0025 in standard form
2.5 x 10(^-3)
Relationship between micrometers and millimetres
1000 micrometers = 1 millimetre
Sperm Cells
- specialised for reproduction
- long tail and streamline
- lots of mitochondria for energy and enzymes
Nerve Cells
- specialised for Rapid Signalling
- long cells to transfer electrical impulses
- branches
Muscle Cells
- specialised for contractions
- long cells
- lots of mitochondria for respiration for energy
Root Hair cells
- specialised for absorbing Water and Mineral ions
- hair stick out into soil giving large SA to absorbs
Phloem and Xylem Cells
- specialised for transporting substances (food and water
- Xylem hollow centres and Phloem few sub-cellular structures for flow
Diffusion (3)
- spreading out of particles
- area of high to low concentration (against a gradient)
- requires energy
Where and why does diffusion occur?
- in solutions and gases that have small molecules, through cell membrane
- particles free to move
3 ways to increase rate of diffusion
- higher concentration gradient
- higher temperature, particles more energy
- increase surface area, more pass through at once
Osmosis (3)
- Movement of water molecules
- from high water concentration to low water concentration (against a concentration gradient)
- across a partially permeable membrane
What is Net Movement in Osmosis?
- steady flow of water molecules into concentrated solution (not water)
3 stages of effects of sugar solution required practicle
1) cut potato and get different solution concentration (independent), with one pure water
2) measure mass (dependant), then leave for 24 hours (control)
3) take out and dry measure mass
3 potential errors of sugar solution required practicle
- not fully dried effects mass
- water evaporated from beakers
- concentration change
Active Transport (3)
- movement of mineral ion
- from low concentration to high concentration (against a concentration gradient)
- requires energy
Active Transport in root hair cells
- allows to absorb minerals from dilute solution
- needs respiration to work
Active Transport to stop us starving
Allows nutrients (gut) into blood due to the concentration gradient
Exchanging surfaces in single-celled organisms
- dissolved substances directly through cell membrane
- large SA:VOL ratio so enough exchanged for volume
4 adaptions of exchanging surfaces
- thin membrane, shorter diffusion
- large SA, lot’s of diffusion
- Animals lot’s of blood vessels to increase rate
- Ventilated gas exchange to keep flow
4 examples of exchanging substances
- gas exchange for respiration
- villi for digestion
- structure of leaves for flow of 02 and CO2
- gills in fish for O2 from water and CO2 leave
