First term (cell biology) Flashcards
What is Diffusion?
The spreading out of particles from an area of high concentration to an area of low concentration.
What are the 7 characteristics of living organisms?
Movement
Respiration
Sensitivity
Growth
Reproduction
Excretion
Nutrition
What is the function of the cell wall?
To support and strengthen the cell
What is the cell wall made of?
Cellulose
What is the function of the cell membrane?
Holds the cell together and controls what goes in and out of the cell
What is the function of the nucleus?
contains genetic material that controls the activities of the cell
What is the function of the cytoplasm?
a gel-like substance where most of the chemical reactions take place (it contains enzymes that controls the chemical reactions)
What is the function of the ribosomes?
the site of protein synthesis (where proteins are made)
What is the function of mitochondria?
Where most of the reactions for aerobic respiration take place (this transfers energy that the cell needs to work)
What is the function of chloroplasts?
The site of photosynthesis (they contain a green substance called chlorophyl which absorbs the light needed for photosynthesis)
What is the function of a permanent vacuole?
contains cell sap
What are plasmids?
smalls rings of DNA that float freely in the cytoplasm of a prokaryotic cell
What organelles are only found in plant cells?
chloroplasts, vacuole, cell wall
How many micrometres go into 1mm?
1,000
How do you calculate the length of an individual cell?
Length of cell = distance/ number of cells
How do you calculate magnification?
Magnification = Image size / actual size
What organisms are made of prokaryotic cells?
bacteria (a prokaryote,a single celled organism)
What organisms are made from Eukaryotic cells?
plants, animals, fungi
What are some characteristics of Eukaryotes?
cells have a nucleus,
cells have membrane bound organelles like mitochondria and chloroplasts
What are some characteristics of prokaryotes?
cells don’t have a nucleus,
cells are much smaller than plant and animal cells (less than 10 micrometres),
can have extra rings of DNA called plasmids,
do not have mitochondria or chloroplasts
Plant or animal cell?
Has the ability to photosynthesize
Plant
Plant or animal cell?
Uses a tail like structure called a ‘flagellum’
animal
Plant or animal cell?
Engulfs tiny particles of plants and animals for nutrition
neither
Plant or animal cell?
Lacks a cell wall, but has protein bands that spiral down its length
neither
Plant or animal cell?
Contains chloroplasts
Plant
Plant or animal cell?
Contains a red eyespot that allows it to sense light
animal
Plant or animal cell?
Contains a nucleus which contains DNA and controls the activities of the cell
both
Plant or animal cell?
Contains a contractile vacuole which enables the cell to control water levels and prevents the cell from bursting?
animal
Plant or animal cell?
Contains cytoplasm where reactions within the cell take place
both
What are the two reasons that cells differentiate in mature animals?
repairing and replacing
What ways can you speed up diffusion?
Heating up the fluid
Shorter distance
Stirring
Increasing the concentration gradient
Larger surface area to volume ratio
Why do bacteria need a larger surface area to volume ratio?
They absorb everything they need through their cell membrane
What is the function of a nerve cell?
To quickly carry messages or electrical impulses from one part of the body to another
What is the function of a muscle cell?
To contract quickly
What is the function of a sperm cell?
To carry the male’s DNA to the female’s DNA in the egg cell
What is the function of a root hair cell?
to absorb water and mineral ions from the soil
What is the function of a phloem cell?
specialised to carry the products of photosynthesis to all parts of the plant
What is the function of a xylem cell?
transport water and mineral ions up the plant from the roots
