Transport
The names for the two types of transport to move water across the membrane
osmosis and facilitated diffusion (via aquaporins)
What are personal errors?
Errors caused by personal mistakes such as misreading a scale or spilling a sample.
how can we minimise the effect of random errors in an experiment
The effect of random errors are unknown so all we can do is do multiple trials and calculate an average to reduce the impact of random variations in each trial on our results
Name one similarity between prokaryote and eukaryote cells
DNA
This organelle controls the cell’s activities and contains the DNA.
Nucleus
Why are cells so small?
How does a control group increase the validity of our bacteria experiment
It tell us that the bacteria can grow under normal conditions without the effect of the antibiotics which means we know any change in bacteria growth is a result of the antibiotics
What are the stages of the cell cycle
G1, S, G2, M (C)
Binary fission
This organelle has an enzyme filled matrix in the centre of it that helps it perform cellular respiration
Mitochondria
The name for the type of transport where a cell engulfs a very large molecule
Endocytosis
What is reproducibility?
The ability of an experiment to be repeated by others and produce consistent results.
What is checked during the G2 check point of the cell cycle
The DNA has replicated correctly and the cell has enough resources to divide
What evidence is there that humans are eukaryotes?
anyone of Multicellular, organelles within cells, sexual reproduction
These organelles contain their own DNA that is distinct from nuclear DNA
Mitochondria and Chloroplast
If a red blood cell is placed in a hypotonic solution in what direction will the water move (into or out of the cell) and what will happen to the cell
Water will move in and the cell will lyse (burst)
What are random errors?
Errors that occur unpredictably, such as fluctuations in temperature or human reaction time.
If there is an error at the G2 checkpoint what will happen
The cell will try to fix the error and if it cannot it will trigger programmed cell death (Apoptosis) via the mitochondrial pathway
Name one difference between prokaryotic and eukaryotic cells
Organelles, single cell vs mostly multicellular, Plasmids, circular DNA - multistranded DNA
This flexible phospholipid bilayer surrounds all cells and controls what enters and exits the cell.
Cell membrane
Why can ions not move across the plasma membrane via diffusion
Ions are charged molecules and are repelled from the hydrophobic region (fatty acid tails) of the phospholipids. Molecules that move via diffusion are usually non-polar (uncharged)
How do we reduce the impact of systematic errors
Calibrate equipment properly before use (e.g., zeroing a balance, checking thermometers).
Use more accurate instruments or ones that have been recently serviced.
Compare results with accepted standards or known values to spot bias.
Use control experiments to check whether the system behaves as expected.
If there is a problem (like a DNA mutation) and it goes undetected at the checkpoints what will happen
The cell will proceed with cell division and produce daughter cells with the same problem. The mutation could lead to uncontrolled cell division and result in a tumor or cancer forming
Why are compartments within cells good
Compartments like organelles allow the cell to have microenvironments that are optimised for different cell processes or chemical reactions (e.g diff PH, large surface areas) which allows the cell to be more efficient and perform more complex functions.
These stacks maximise the surface area for photosynthesis in the chloroplast
Thylakoid/granum