B1 Flashcards
What do xylems do?
Transport water and dissolved mineral ions up the plant
How to find the total magnification of a light microscope?
Objective * eyepiece
What is the IAM triangle?
Image size= actual size * magnification
Actual size= image size/ magnification
Magnification= image size/ actual size
How to convert cm to mm to micrometers to nm?
Cm to mm= /10
Mm to micrometers= /1000
Micrometers to nm= /1000
Light microscopes- what are the disadvantages and how does it work?
It uses light to create an image, and it’s limiting factor is the resolution
Electron microscopes- what are the advantages, how does it work?
It uses a ray of electrons, and can only observe dead animals. It can view these at a higher resolution and magnifications, so it observes greater detail
What are 6 specialised cells and roughly describe how they’re specialised?
Sperm cells- long tail for swimming and lots of mitochondria so the sperm can swim
Red blood cells- no nucleus for more room to carry oxygen, bi-concave shape for increased surface area
Muscle cell- lots of mitochondria for the muscles to contract, protein fibres to contract to make cells shorter
Nerve cell- branched endings (dendrites) o make connections with other neurones, myelin sheath insulates the axon to increase the transmission speed of the electrical impulses
Root hair cell- long projection for more effective absorption of water, lots of mitochondria to release energy for the active transport of the mineral ions from the soil
Palisade cell- lots of chloroplasts for more light absorption, located at the top of the leaf- most sunlight
What type of cells are animal and plant cells?
Eukaryotic
What type of cells are bacteria and yeast cells?
Prokaryotic
Can either light or electron microscopes have coloured images?
Light microscopes can, but electron microscopes are in black and white
What is active transport?
Movement of substances against the concentration gradient (less concentrated to more concentrated) with the use of energy from respiration, making it an active process.
What is an adult stem cell?
A type of cell that can form many types of cells, but are more limited compared to embryonic stem cells
What is agar jelly?
A substance placed in Petri dishes which is used to culture microorganisms on
What is cell differentiation?
The process where a cell becomes specialised to its function
What is the cell membrane’s function?
To control what substances go in and out a cell. It is a semi permeable barrier that surrounds the cell
What is the function of a cell wall?
To protect the cell and maintain the cells shape
What are chromosomes?
DNA structures that are found in the nucleus, and are made up of genes
What is diffusion?
Movement of particles from a more concentrated area to a less concentrated area. This makes it a passive process as it doesn’t require energy
What is an embryonic stem cell?
A type of cell that can differentiate into most types of human cells
What is an eukaryotic cell?
A type of cell found in plants and animals that have a nucleus
What is the magnification of an object?
How much bigger an image appears compared to it’s actual size
What are meristematic cells?
Cells that can differentiate into any type of plant cell
Where does respiration occur?
In the mitochondria
What is the function of a nucleus?
It contains the generic material and controls the activities
What is an organelle?
A specialised structure found inside a cell
What is osmosis?
The diffusion of water from a dilute solution to a concentrated solution through a PARTIALLY PERMEABLE MEMBRANE
What are plasmids?
Loops of DNA found in the cytoplasm of prokaryotic cells
What is a prokaryotic cell?
A type of cell found in bacteria that do not have nucleus
What is the resolution of something?
The distance between two points in a specimen
What are specialised cells?
Cells that are adapted to perform a certain function
What are stem cells?
Undifferentiated cells that can divide to produce many specialised cells of the same type
What is the cell cycle?
The stages of preparation for a cell to divide
What is the cell cycle?
The stages of preparation for a cell to divide
What is therapeutic cloning?
Producing an embryo that has the same genes as the patient
What is the function of a vacuole?
It’s an organelle that stores cell sap and also helps the cell keep its shape
How are nerve cells specialised?
1.) Lots of DENDRITES- make connections to other neurones
2.) AXON- carries nerve impulses from one point to another
3.) Very long
4.) Lots of mitochondria to PROVIDE ENERGY NEEDED TO MAKE TRANSMITTER CELLS
How are root hair cells adapted?
1.) Large surface area
2.) Large, permanent vacuole
3.) Lots of mitochondria that transferred energy needed for active transport of minerals into the root hair cells
How are muscles cells adapted?
1.)Contain special proteins
2.) Store glycogen
3.) Lots of mitochondria to transfer energy needed to complete the reactions needed for contraction and relaxation
How are phloems adapted to carry out their function?
1.) Cell wall breaks down to from special sieve plates
2.) Lose a lot of internal structures but are supported by companion cells to keep them alive
3.) Mitochondria of companion cells transfer the energy to move dissolved food up and down in the phloem
How are xylems adapted to their function?
1.) Alive when they’re first formed, but die to allow water and minerals to move through them
2.) Spirals make them strong and sturdy to help withstand the water pressure and support the stem of the plant
What are the three cycles of cell division?
1.) Growth and replication of the DNA
2.) Mitosis (nucleus divides)
3.) Cell divides into 2
What is cell division called in bacteria?
Binary fission
Where can you source stem cells?
Bone marrow- used to treat leukaemia
Embryos- donated spare IVF embryos
Umbilical cord
Adults- heart, liver, skin, kidneys
What is diffusion?
When molecules move from an area of high concentration to low concentration
What are the 4 factors that affect diffusion?
1.) Higher temperatures
2.) Higher concentration difference
3.) Larger surface area
4.) Shorter distance
What is the solute, solution and solvent?
Solute- the solid that is dissolved into the solution
Solvent- the liquid that the solid is dissolved into
Solution- solute dissolved in a solvent
What is osmosis?
Moves from a high WATER concentration to a low WATER concentration through a SEMI PERMEABLE MEMBRANE (only in water)
What is active transport?
Goes against the concentration gradient (low to high concentration)
It requires ENERGY from respiration and a CARRIER PROTEIN
