B1 Test Flashcards
How many micrometres in a mm
1000
How many nanometres (NM) in a micrometre (Um)
1000
What are Electron microscopes usually used to magnify
Sub-cellular structures inside cells
How can you calculate the magnification you are using
Magnification of eyepiece lense X magnification of objective lens
What is the formula for magnification
Magnification = size of image/ size of real object
How much can light microscopes magnify objects?
2000 X
How much can Electron microscopes magnify objects?
2000000 X
what is the cell membrane
The membrane around the contents of a cell that controls what moves in and out
What is Cellulose
The complex carbohydrate that makes up plant and algal cell walls and gives them strength
What is the Cell Wall
The rigid structure around the plant and algal cells that is made from cellulose and strengthens the cell
What are Chloroplasts
The organelles in which photosynthesis take place
What is Chlorophyll
The green pigment contained in chloroplasts
What is cytoplasm
The water-based gel in which the organelles of all living cells are suspended
What is the permanent vacuole
A space in the cytoplasm filled with cell sap
What do plant cells contain that animal cells do not
Chloroplasts, permanant vacuole and cell wall
What are some features of eukaryotic cells
A cell membrane, cytoplasm and genetic material enclosed in a nucleus
What are some features of Prokaryotic cells
They consist of cytoplasm an a cell membrane surrounded by a cell wall. No nucleus. Genetic material in a single dna loop.
Are bacteria eukaryotic cells of prokaryotes
Prokaryotes
Name 3 specialised animal cells
Muscle cells, nerve cells and sperm cells
what is one adaptation of a sperm cell
A long tail to swim
What is one adaptation of a muscle cell
They contain special proteins that slide over each other making the fibres contract
What is one adaptation of a nerve cell
They are adapted to carry electrical impulses from one part of the body to another
What are 3 examples of specialised plant cells
Root hair cells, xylem cells and phloem cells
What is one adaptation of a xylem cell
Very strong and are able to withstand the pressure of water moving up the plant.
What is one adaptation of a root hair cell
They have a large permanent vacuole to speed up the movement of water into the plant
What is diffusion
The spreading out of particles from an area of high concentration to low concentration down a concentration gradient
What are 3 things that the rate of diffusion can be affected by
The difference in concentrations, the temperature and the space
What is osmosis
The movement of water from a dilute to a more concentrated solution through a partially permeable membrane.
What causes osmosis
Differences in the concentration of solutions inside and outside a cell
What is active transport
It is the movement of substances from a more dilute solution to a more concentrated solution (against a concentration gradient) using energy released from food in respiration.
What surface to volume ratio do single-celled organisms have?
A relatively large surface area to volume ratio
what are ribosomes
where protein synthesis takes place
What are the features of prokaryotic cells
cytoplasm, cell membrane, flagella, DNA loops
What is the flagella
A long protein strand that lashes out to move themselves
What is mitochondria
The organelle where respiration takes place
