B1 quick questions Flashcards
what are examples of eukaryotic cells
animal and plant
what type of cell are bacteria
prokaryotic
where is dna found in eukaryotic cells
nucleus
what is the function of the cell membrane
controls movement of substances in and out of the cell
what is the function of the mitochondria
to release energy through respiration
what is the function of the ribosomes
protein synthesis
what is the function of chloroplasts
photosynthesis contain chlorophyll
what is the function of the cell wall
strengthens and supports the cell
what is the structure of the main genetic material in a prokaryotic cell
single loop of dna
how are electron microscopes different to light microscopes
electron microscopes use electron beams instead of light, cannot be used to view the living samples, are much more expensive, and have a much higher magnification and resolution
what is the function of a red blood cell
carries oxygen around the body
three adaptations of a red blood cell
no nucleus contains haemoglobin has a bi-concave disk shape
what is the function of a nerve cell
carries electrical impulses around the body
two adaptations of a nerve cell
branched endings and a myelin sheath insulates the axon
function of a sperm cell
fertilises an ovum
two adaptations of a sperm cell
tail and contains lots of motochondria
function of a pallisade cell
carries out photosynthesis
two adaptations of a pallisade cell
lots of chloroplasts, located at the surface of the leaf
function of a root hair cell
absorbs water and minerals from soil
two adaptations of a root hair cell
lots of mitochondria and long projection
what is diffusion
net movement from an area of high concentration to an area of low concentration along a concentration gradient- this is a passive process meaning it does not require energy from respiration.
name three factors that affect the rate of diffusion
concentration gradient, temperature, membrane surface area
how are villi adapted for exchanging substances
- long and thin, increases sa
- one cell thick membrane, short diffusion pathway
- good blood supply, maintains a steep concentration gradient
how are the lungs adapted for efficient gas exchange
- alveoli, large sa
- moist membranes, increases rate of diffusion
- one cell thick, short diffusion pathway
- good blood supply, maintains a steep concentration gradient
how are fish gills adapted for efficient gas exchange
- large sa for gases to diffuse across
- thin layer of cells, short diffusion pathway
- good blood supply, maintains a steep concentration gradient
what is osmosis
diffusion o water from a dilute solution to a concentrated solution through a partially permeable membrane
give one example of osmosis in a plant
water moves from the cell into the root hair cell
active transport
movement of particles against a concentration gradient from a dilute solution to a more concentrated solution using energy from respiration
why is active transport needed in plant roots
concentration of mineral ions in soil is lower than inside the root hair cells the mineral ions must move against the concentration gradient to enter the root hair cells
what is the purpose of active transport in the small intestine
sugars can be absorbed when the concentration of sugar in the small intestine is lower than the concentration of sugar in blood
