Module 2: Cellular organisation and Stem Cells Flashcards
What is the order of the levels of organisation in multicellular organisms
specialised cells
tissues
organs
organ systems
organism
What is a tissue
What is an organ
What is an organ system
a group of specialised cells that all have the purpose of performing a particular function
a group of tissues that work to perform a wider function
a group of organs that work together to perform an essential life function
What are the 2 tissue types commonly found in plants
xylem tissue and phloem tissue
What is the function of xylem tissue
What is its structure 3
Where is xylem tissue produced
to transport water and minerals as well as providing structural support
they are long cylinders made of dead tissue with open ends , they are thickened by a tough substance called lignin
produced by meristem cells
What is the phloem tissue involved in?
Where and how is it produced
3
its involved in translocation
it is produced by meristem tissue , it produces cells that elongate and line up end to end to form a long tube
their ends produce perforated structures called sieve plates and metabolically active companion cells are found next to the plates and help to mediate the movement of photosynthesis products in the tubes
What is translocation
the movement of food substances and nutrients from leaves to storage organs and growing parts of the plant
What is the composition of epithelial tissue
What are the 2 types
a sheet of cells that lines or covers a surface
squamous and ciliated
What is the composition of squamous epithelial tissue and where is an example of its location
-cells produce a very smooth , flat and thin surface where they are packed tightly together
EG-lining of blood vessels and cheeks
What is the composition of ciliated epithelial tissue and where is an example of its location
-composed of column shaped cells containing cilia which form from the lining
-the trachea and bronchi
What are the 4 main tissue types in animals and how are they specialised
nervous-adapted to support transmission of electrical impulses
epithelial-adapted to cover a body surface
muscle-adapted for movement through contraction
connective-adapted to hold other tissues together or to act as a transport medium
What is a stem cell
an undifferentiated cell that has the ability to specialise and become any type of cell
What is the process by which stem cells specialise called and what happens to them once they become specialised
differentiation
they become adapted to their role and lose their ability to divide
What are the 3 different types of stem cell
totipotent
pluripotent
multipotent
What can a totipitent stem cell do
differentiate into any type of cell including placental cells , they have the ability to form an entire organism
What can pluripotent stem cells do
differentiate into any type of cell excluding placental cells so they cant form an entire organism
What can multipotent stem cells do
only differentiate into specific predetermined cell types (eg blood cells)
Stem cells found in bone marrow can differentiate into what types of cell
erthrocytes ( red blood cells) and neutrophils ( white blood cells)
What are the 2 main sources of stem cells in animals and what kind of stem cell are they
embryonic stem cells-they are totipotent until after 7 days when they have formed a mass of cells (blastocyst) and are now pluripotent until birth
adult(tissue) stem cells-are multipotent and found in areas like bone marrow
What is the main source of stem cells in plants and where is it located
meristem tissue which is found wherever growth is occuring and also between the phloem and xylem tissues
What is the name of the region between the xylem and phloem tissues
the vascular cambium
What type of stem cells are produced by meristem tissue
pluripotent stem cells
Can plants retain their ability to differentiate forever
yes
What are the uses of stem cells in research and medicine
(5)
repair of damaged tissues
treatment of neurological disorders such as Alzheimers and Parkinson’s disease
treatment of burns
drug trials as drugs can be tested on stem cell cultures
to study development of multicellular organisms
