Biology - Topic 1 - Cell Biology Flashcards
What are eukaryotic cells?
Cells which contain a nucleus
Whats a prokaryotic cell?
Cells which dont contain a nucleus
What are organism’s which are made from eukaryotic cells called?
Eukaryotes
What are organism’s which are made from prokaryotic cells called?
Prokaryotes
Difference between Eukaryotes and Prokaryotes?
Eukaryotes are usually multicellular, whereas prokaryotes are single celled
Whats the function of a nucleus
A nucleus holds all genetic material needed to control the cell activities
Whats the function of a mitochondria?
Contain’s enzymes needed for respiration, to release energy
What’s the function of a cytoplasm?
Jelly-like substance which contain’s nutrients, salts and enzymes required for chemical reactions
Whats the function of a semi-permeable cell membrane?
Control what comes in and out of cells
What’s the function of a ribosomes?
Production of proteins
What’s the function of a cell wall?
Provides protection and structure to the cell
What extra features do plant cells have which animal cells don’t?
Cell wall, vacuole, chloroplasts
What’s the function of a vacuole?
Holds weak solution of sugar and salts called cell sap to keep the cell swollen
Whats the function of a chloroplast?
Site of photosynthesis
What are cell walls made of?
Cellulose
What other cell also have features of a cell wall
Algal Cells
What does chloroplasts contain?
Chlorophyll, a green pigment ,which absorbs light and specific enzymes that are needed for photosynthesis and food to be produced
Where is the genetic material in a prokaryotic cell?
The genetic material is free in the cytoplasm
What does a prokaryotic cell contain?
Circular strand of DNA, Cell membrane, cell wall cytoplasm and occasionally a plasmid
What’s the function of a plasmid?
Small ring of DNA
What does bacterial cells sometimes contain?
Flagella which are hair like structures that help the bacteria move
Whats differentiation of a cell?
Cells develop subcellular structures to perform its job
When does differentiation happen in animal and plant cells
In animal cells, most cells differentiate in the early stages of its life
However for plants the ability to differentiate is never lost
What are stem cells?
Undifferentiated cells which have the ability to develop into any cell
What is the function of a sperm cell?
Designed for the effective transport of male DNA to female DNA for sexual reproduction
Function of the head of a sperm cell??
The head contains all genetic information. It also has enzymes to digest the cell membrane
How are sperm cells differentiated to perform its job more efficiently?
.Have lots of mitochondria for energy for more movement time
.Has a tail to swim
Have enzymes to digest the cell membrane
What are the function of nerve cells?
Carry electrical impulses
Why do muscle cells need to be specialised?
To contract quickly
How are nerve cells specialised
Carry electrical impulses rapidly
Long axon to carry impulses for long distances
Branched at both ends to connect and pass signals between one another
Insulated of fatty sheath to help impulse move quicker
How are muscle cells specialised
Contain lots of mitochondria to provide energy for contraction and have protein filament to help slide over and contract.
Why are xylem cells specialized?
Form xylem vessels to transport water and dissolved ions
Where are root hair cells found
Plants roots to increase surface area for more efficient absorption
How are root hair cells specialised?
Vacuole full of cell sap which is more concentrated than soil water creating a water potential gradient and more efficient water absorption
Lots of mitochondria to provide energy for active transport of mineral ions from the soil
What are root hair cells specialised for?
Exchange surface to absorb water and nutrients from the soil
Difference between xylem and phloem cells
Phloem cells are living where as xylem cells are not
What are phloem cells specialized for?
Transport of sugars and amino acids around the plant. Cells are joined to joined with sieve plates between them to allow passage of substances
How have xylem cells been specialized?
Xylem are dead and hollow, and don’t have a top and bottom cell wall, subcellular structures or cytoplasms for water to be drawn upwards
Magnification and resolution of a Light Microsope
Magnification : 1500x
Resolution: .2 Micrometre
What did light microscopes allow to do?
View individual cells and their larger subcellular structures such as a nuclei
How do light microscopes work?
Use light and senses to create a magnified image of a specimen.
What are electron microscopes?
Use electron beams
Difference between a Light and Electron microscope
Electron beams have smaller wavelengths than light beams
Electron has a higher magnification and resolution power
What do electron microscopes allow you to see which, light microscopes don’t?
Mitochondria, chloroplasts, nuclei and ribosomes and plasmids
What’s resolution
Ability to distinguish between two points
What are chromosomes?
Coiled up DNA found in the nucleus
What process do eukaryotic cells use to divide?
Mitosis
What are genes?
section of DNA which control development of specific characteristics