Chapter 1: Cell Structure And Transport Flashcards
State an advantage of a light microscope
Relatively Cheap
State a disadvantage of a light microscope
Can only magnify several hundred times
State an advantage of an electron microscope
Magnifies objects 2 000 000 times
State a disadvantage of an electron microscope
Large and very expensive
What does the nucleus do?
Controls all of the activities of the cell, and contains genes on the chromosomes that carry the instructions for making the protein needed to build new cells.
What does the cytoplasm do?
A liquid gel where organelles are suspended
What does the cell membrane do?
Controls the passages of substances
What does the mitochondria do?
Where aerobic respiration takes place, releasing energy for the cell.
What do the ribosomes do?
Make all of the proteins needed in the cell
Why do all plants have cellulose and a cell wall?
To strengthen the cell and give it support
What is chlorophyll?
Chlorophyll absorbs light so the plant can make food by photosynthesis
What is a permanent vacuole?
A place in the cytoplasm filled with cell sap, that make the plant more rigid
What is a Eukaryotic cell?
Eukaryotic cells all have a cell membrane, cytoplasm, and genetic material which is enclosed in a nucleus
Give 2 examples of Eukaryotic cells
- Animals cells
2. Plant cells
What is a Prokaryotic cell, give an example
Genetic material is not enclosed in a nucleus. An example would be Bacteria.
Give 2 adaptations of nerve cells
- Lots of dendrites to make connections to other nerve cells
- Contain lots of mitochondria
Give 3 adaptations of muscle cells
- They have special proteins that slide over each other making the fibers contract
- Contain many mitochondria to transfer the energy needed
- They store glycogen which can be used in cellular respiration
Give 3 adaptations on sperm cells
- A long tail whips from side to side
- The ‘head’ is full of mitochondria to transfer energy
- Large nucleus contains genetic information that needs to be passed on
Give 3 main adaptations of root hair cells
- Increased surface area
- Large permanent vacuole which speeds up the process of osmosis
- Many mitochondria
What is diffusion?
The spreading out of the particles of any substance in a solution, or particles in a gas, resulting in a net movement of particles from an area of high concentration to low concentration down a concentration gradient
How do you calculate the net movement?
net movement= particles moving in-particles moving out
Diffusion occurs _______ a concentation gradient
a) up
b) down
b) down
Name 3 materials that enter and leave cells by diffusion
1) oxygen
2) carbon dioxide
3) glucose
How do villi increase surface area in a cell?
Folds in the cell membrane form microvilli, which increase the surface area of the cell
Name 3 factors which affect the rate of diffusion
1) Difference in concentration
2) Temperature
3) Available surface area
What is osmosis?
A special type of diffusion in which only water moves across a partially permeable membrane from a dilute solution to a concentrated solution
What are partially permeable membranes?
Membranes that only let some types of particles through
A dilute solution of sugar contains a _______ concentration of water and _______ concentation of sugar
high, low
A concentrated solution of sugar contains a _______ concentration of water and _______ concentation of sugar
low, high
Define isotonic
When the concentration of solutes in the solution outside the cell is the same as the internal concentration
Define hypertonic
When the concentration of solutes in the solution outside the cell is higher as the internal concentration
Define hypotonic
When the concentration of solutes in the solution outside the cell is lower as the internal concentration
Why do plants need osmosis?
To make them turgor
What is active transport?
The movement of substances from a dilute solution to a more concentrated solution against a concentration gradient, requiring energy from respiration.
Name 4 adaptations for exchanging materials
1) Large surface area
2) Thin membrane for short diffusion path
3) Efficient blood supply
4) Being ventilated
