2- cell structure Flashcards
nucleus
contains genetic material in chromosomes which controls how the cell works and grows
controls cell division
cytoplasm
- supports cell structures
- site of many chemical reactions
- contain water and many solutes
cell membrane
- holds cell together
- controls substances entering and leaving the cell
chloroplasts
-site of photosynthesis
vacuole
- contains cell sap
- used for storage of certain material
- also helps support the shape of the cell
mitochondiria
-site of aerobic respiration, providing energy for the cell
what does the amount of mitochondria depend on?
cells with higher metabolism will have more mitochondria
ribosomes
-site of protein production in protein synthesis
vesicles
-used to safety transport substances from. one part of the cell to another
an animal cell contains-
nucleus, cell membrane, mitochondria, ribosomes, cytoplasm
a plant cell contains-
nucleus, cell membrane, mitochondria, ribosomes, cytoplasm, cell wall, vacuole, chloroplasts
cell wall
gives the cell extra support and defines the shape
when a cell differentiates…
it develops a structure and composition of subcellular structures which enables the cell to carry out a certain function
what happens to the multicellular organisms when they develop?
their cells differentiate to form specialised cells
in an animal most cells differentiate…
at an early stage of development so as a result the animal cells lose their ability to differentiate early in the life of the organism
undifferentiated cells are called
adult stem cells
what do adult stem cells do?
replace and repair cells
plants differentiate…
throughout their whole lives not just the early stages of development
specialised cells are
those which have developed certain characteristics in order to perform particular functions
what are specialised cells controlled by?
genes in the nucleus
cells specialise by undergoing
differentiation
differentiation
process by which cells develop the structure and characteristics needed to be able to carry out their functions
stem cell
undifferentiated cell of an organism which is capable of dividing to produce many more cells of the same type
meristem cells
cells in plants that can differentiate into the cells needed by the plant in regions where growth is occuring
modern science means its possible to grow..
human embryos in the lab and extract embryonic stem cells from them
modern science made embryonic stem cells can be encouraged to…
differentiate into most type of specialised cells
there is potential for scientists to use stem cell technology to..
repair damaged organs by growing news tissues from stem cells
how can stem cells help diabetes (type 1)
stem cells could be differentiated into insulin- producing pancreatic cells which are transplanted into the patients body
where can scientists get stem cells
stem cell donors or therapeutic cloning
how can stem cells help paralysis
stem cells could be differentiated into nerve cells (neurones) which are transplanted into the damaged region of the nervous system
therapeutic cloning
an embryo is produced with the same genes as the patient
benefits of using stem cells in medicine
- great potential to treat a wide variety of diseases
- organs developed from patients own stem cells would decrease risk of rejection and the wait of organ donation
risks/issues of using stem cells in medicine
- stem cells made in a lab could be infected with a virus and that could be transmitted to patient
- cultured stem cells could accumulate mutations which can lead to the development of cancer cells
- low numbers of stem cell doners
social issues of using stem cells in medicine
- lack of evidence of the success of stem cells
- stem cells can be collected pre birth (from amniotic fluid) or after birth (umbilical cord) and stored in clinic but this is expensive
ethical issues of using stem cells in medicine
- stem cells may be sourced from unused embryos in IVF treatment but is it right to use them? when does life begin?
- is it right to make embryos through therapeutic cloning and then destroy them? who owns them?
- should an embryo be treated as a person with human rights? or as a commodity?
