B1- cell biology and transport Flashcards
What are two types of eukaryotic cells?
animal and plant
What type of cell are bacteria?
prokaryotic
Where is DNA found in animals and plants?
Nucleus
What is the function of the cell membrane?
controls the movement of substances in and out of the cell
What is the function of chloroplasts?
contains chlorophyll to absorb light energy for photosynthesis
What is the function of ribosomes?
enables production of protein, protein synthesis.
What is the function of the cell wall?
Strengthens the cell
What is the structure of the main genetic material in
a prokaryotic cell?
a single loop of DNA
How are electron microscopes different to light microscopes?
Electron microscopes use: beams of electrons instead of light.
Are more expensive
Have much higher magnification.
What is the function of a red blood cell?
To carry oxygen around the body.
Give 3 adaptations of a red blood cell.
Large surface area - bi-concave shape
No nucleus
Has haemoglobin- a red pigment
What is the function of a nerve cell?
To carry electrical impulses around the body.
Give 2 adaptations of a nerve cell?
branched endings
myelin sheath insulates axon
What is the function of a sperm cell?
To fertilise the ovum (egg)
Give 2 adaptations of a sperm cell?
A tail- to swim to fertilise the egg.
Contains lots of mitochondria
What is the function of a palisade cell?
Carries out photosynthesis in the leaf.
Give 2 adaptations of a palisade cell
Lots of chloroplasts
Located at the top of the leaf
What is the function of the root hair cells?
absorbs water and mineral ions
GIve 2 adaptations of root hair cells.
Long projection
Lots of mitochondria
What is diffusion?
Net movement of particles from an area of high concentration to and area of low concentration along a concentration gradient- this is a passive process.
Name 3 factors that affect the rate of diffusion
Temperature, concentration gradient, membrane surface
How are the villi adapted for exchanging substances?
Thin walls - short diffusion path.
Large surface area
Good blood supply- maintains a steep concentration gradient
How are the lungs adapted for gas exchange?
large surface area- alveoli
one cell thick membranes- short diffusion path
good blood supply - maintains a steep concentration gradient
How are fish gills adapted for gas exchange?
good blood supply- maintains a steep concentration gradient
Large surface area- for diffusion
Thin layer of cells- short diffusion path