Chapter 8: Cells and Transport Flashcards
What is the cell wall?
The cell wall is used to support and protect the plants cell; it stops the cell from bursting when it is turgid.
What is the function of the permanent vacuole?
It is used to store food, water and waste in plant cells.
What is a lysosome?
It is a special type of vacuole that breaks down old cell parts and large molecules. It is only found in animal cells.
What is the ER?
Aka endoplasmic reticulum. It is used for the transport of chemicals and proteins within cells.
What is the function of the Golgi?
The Golgi modifies proteins to make them functional and transports proteins within cells.
What does the cytoskeleton do?
It is the support structure within cells, made up of proteins.
Name the differences between onion cells and cheek cells.
Onion cells are regular in shape, tesselate and have thicker edges due to a cell wall, whilst cheek cells are irregular in shape.
Describe growth and development.
An increase in number of cells in an organism.
What is diffusion?
The movement of molecules down a concentration gradient.
How does concentration gradient affect the diffusion rate?
The greater the concentration gradient, the faster the rate of diffusion.
How does diffusion distance affect the diffusion rate?
The longer the diffusion distance, the slower the rate of diffusion.
How does surface area affect the rate of diffusion?
The larger the surface area, the faster the rate of diffusion.
How does temperature affect the diffusion rate?
The higher the temperature, the faster the rate of diffusion
How does size affect the rate of diffusion?
Having a small SA/V ratio causes the rate of diffusion to be slower.
What is osmosis?
The movement of water from an area of high water concentration to an area of low water concentration across a selectively-permeable membrane.
Name a difference between bacteria and viruses.
Bacteria have various organelles, whereas viruses don’t.
What does it mean to have no net movement?
When there is an equal concentration of molecules there is no net movement.
When plotting a graph in biology, what should I remember?
- Independent variable goes on the x-axis.
- Dependent variable goes on the y-axis
- Bar graph if you have categorical data, but a line graph if you have discrete or continuous data.
- Join the dots with straight lines.
Nerve cell
Function: transmission of nervous stimuli
Adaptation: very long axon, makes neurotransmitter
Ciliated cell
Function: eg. clearing of airways
Adaptation: cilia that beat back and forth to move material
Sperm cell
Function: fertilisation of egg
Adaptation: tail for movement, many mitochondria, acrosome with enzymes to digest egg membrane, genetic information
egg cell
Function: fertilisation
Adaptation: large and bulky, contains food for developing embryo, genetic information
RBC
Function: transport of oxygen
Adaptation: contains haemoglobin, no nucleus
WBC
Function: destruction of pathogens
Adaptation: different purposes
muscle cell
Function: contraction
Adaptation: long and flexible, lots of mitochondria
fat cell
Function: store fat
Adaptation: little cytoplasm, few mitochondria, can expand
rods and cones
Function: photoreception - vision
Adaptation: contrain visual pigment, many mitochondria, synapse that transmits signal to optic nerve
skin cell
Function: protection, heat regulation
Adaptation: pigments to absorb UV, hair for insulation
palisade cells
Function: photosynthesis
Adaptation: lots of chloroplasts, tightly packed, elongated
root hair cell
Function: uptake of water and minerals
Adaptation: have root hair, large permanent vacuole, close to xylem
guard cell
Function: control opening and closing of stomata
Adaptation: can take up and release water by osmosis to open and close stomata, thickened cell wall
