topic 1 - cell biology Flashcards
animal and plant cells are examples of what
eukaryotes
bacteria cells are examples of what
prokaryotes
similarities of animal and plant cells
cell membrane
nucleus
cytoplasm
mitochondria
ribosomes
plant cell differences are
cell wall
permanent vacuole
chloroplast
what do bacteria cells consist of
cell membrane
cell wall
ribosomes
cytoplasm
circular strands of dna
flagella
plasmids
magnification equation
magnification=image size/object size
key features of sten cells
they divide by mitosis to form more crlls
also able to differentiate into specialised cells
embryonic stem cells
can differentiate into any type of cell
where are adult stem cells found and what can they differentiate into
in bone marrow
platelets white blood cells and red blood cells
where are plant stem cells found and what do they differentiate into
in the meristem
phloem and xylem cells
palisade cell
root hair cell
key points specialised cells
specialised cells have a specific role in the body to help them fulfil that role they have a specific shape or structure
differentiation meaning
the process by which cells become specialised
cause of type 1 diabetes
damage to the pancreas cells that normally produce insulin
sometimes the cause of paralysis is
damaged nerve cells
draw backs of embryonic stem cells
requires embryonic stem cells
limited supply
ethically issues such as potential for human life other people think that the benefits of curing existing people who are suffering is more important
rejection from patient because patients genome is different
risks of using stem cells in medicine
if the donor stem cells are infected with a virus then when there transferred to patient it will infect the patient
another risk would be tumor development since stem cells divide so quickly they could be out of control once theyve been transplanted and could develop into a tumor/cancer
what is diffusion
Diffusion is the spreading out of the particles of any substance in solution, or particles of a gas, resulting in a net movement from an area of higher concentration to an area of lower concentration.
what affects diffusion
Two factors affect diffusion:
The type of substance - substances diffuse more quickly through gases than through liquids. This is because the particles in a gas are more spread out and move faster than the particles in a liquid.
Temperature - the hotter the gas or liquid, the faster diffusion happens. This is because the particles have more energy and move faster at higher temperatures.
what is osmosis
osmosis is the net movement of water molecules across a partially permeable membrane from a region of higher water concentration to a region of lower water concentration
what is active transport
movement of molecules across a cell membrane from a region of lower concentration to a region of higher concentration and requiring energy from cellular respiration
where is active transport used
used in plants specifically in the root hair cells
what minerals does active transport deal with
magnesium ions and nitrates
how are root hair cells adapted to their role
root hair cells use active transport to absorb mineral ions and are adapted to that role because of having a large surface area and lots of mitochondria
what are specialised exchange surfaces
the parts of an organism over which they exchange substances with their environment
examples of specialised exchange surfaces and what they do
alveoli which is used to exchange oxygen and carbon dioxide
villi used to absorb nutrients such as glucose and amino acids
common features specialised exchange surfaces share
1)large surface area so lots of molecules can diffuse across at the same time so higher rate of diffusion
2)exchange surfaces are usually very thin so diffusion can take place more quickly
3)exchange surfaces are permeable to the substances that need to exchange
