Cell Organisation and Specialisation Flashcards
Why do cells specialise?
To complete specific functions in multicellular organisms
What are the levels of organisation in a multicellular organism? (in order)
Specialised cells, tissues, organs, organ systems, organism
Name some examples of specialised animal cells
Erythrocytes, neutrophlis, sperm
Name some examples of specialised plant cells
Palisade cells, root hair cells, guard cells
What is a tissue?
A collection of specialised cells that have differentiated for a specific function(s)
What are the categories of tissues in animals?
Nervous, epithelial, muscle, connective
What is the function of nervous tissue?
Support transmission of electrical impulses
What is the function of epithelial tissue?
Cover body surfaces, internal and external
What is the function of muscle tissue?
Contraction
What is the function of connective tissue?
Hold tissues together or transport
How are erythrocytes adapted for function?
(Red blood cells) biconcave shape to increase SA:V, no nucleus for more room for hemoglobin, flexible for squeezing through capillaries; all to aid transport of oxygen
How are neutrophils adapted to function?
(White blood cells) multilobed nucleus to squeeze into small places, granular cytoplasm containing lots of lysosome for digesting foreign bodies
How are sperm adapted to fucntion?
Flagellum for movement, many mitochondria to provide energy for movement, acrosome with digestive enzyme to digest ovum for fertilisation
How are palisade cells adapted to function?
Contains chlorophyll to absorb light for photosynthesis, box shaped to pack together more, thin cell walls to increase rate of diffusion, large vacuole to maintain internal pressure
How are root hair cells adapted to function?
Long thin root hairs to increase SA:V ratio to absorb more water and minerals
How are guard cells adapted to function?
Thicker on one side to maintain symmetrical shape, swell up to prevent gas exchange
Name some examples of specialised tissues in animals
Squamous epithelium, ciliated epithelium, cartilage, muscle
How is squamous epithelium adapted to function?
One cell thick to increase rate of diffusion, lining of lungs
How is ciliated epithelium adapted to function?
Hair-like structure to move substances, goblet cells are also present to move mucus away from lungs, also prevents other substances such as bacteria entering the lungs, lines trachea
How is cartilage adapted to function?
Found in outer ear, nose, bones. Flexible, prevents the ends of bones rubbing together and causing damage
What are the categories of tissues in plants?
Epidermis and vascular
Give some examples of tissues in plants
Epidermis, xylem tissue and phloem tissue
How is epidermis (in plants) adapted to function?
A waxy cuticle to prevent water loss, stomata in epidermis aids gas exchange,
How is xylem tissue adapted to function?
Made of vessel elements (dead, elongated cells) which aid structural support in the xylem
How is phloem tissue adapted to function?
Sieve tubes with porous sieve plates for organic solutes to pass through
What are organs?
A collection of tissues that are adapted for a specific function/functions
Name an example of an animal organ
Mammalian heart, pumps blood around the body and is made of connective tissue and muscle tissue
Name an example of a plant organ
Leaf, for photosynthesis and is made of epidermis and vascular tissue
What are organ systems?
A number of organs working together to carry out a major function
Name an example of an animal organ system
Cardiovascular system, moves blood around the body to make an effective transport system for substances
What are stem cells?
Undifferentiated cells with the potential to differentiate into another type of cell
What is differentiation?
The process of a cell becoming specialised
What is stem cell potency?
A stem cell’s ability to differentiated into different kinds of cells
What are the different types of stem cell potency?
Totipotent, pluripotent and multipotent
What is a totipotent stem cell?
A cell with the potency to become any type of cell and a whole new organism
What is a pluripotent stem cell?
A cell with the potency to differentiate into new tissues
What is a multipotent stem cell?
A cell with the potency to differentiate into a range of cells within a tissue
Why do cell differentiate?
To take on different roles in multicellular organism’s tissues and organs
What are the types of stem cells in animals?
Embryonic stem cells, adult tissue stem cells
What are embryonic stem cells?
Stem cells that present very early in embryo development and are totipotent
What are adult tissue stem cells?
Stem cells that present all throughout life from birth in areas like the bone marrow and are multipotent
What are stem cells in plants called?
Meristems
Where are meristems found?
Wherever growth is occurring, such as the leaves and roots. Also in between the xylem and phloem tissue in the vascular cambium
What are some uses of stem cells?
Repair of damaged tissues such as damages muscle tissue after a heart attack, the treatment of neurological conditions such as Alzheimer’s and Parkinson’s
What are some ethical complications to do with stem cells?
Some believe that life begins at conception, and since the embryo has to be aborted and destroyed to harvest the stem cells, they believe that it is ‘murder’ and the loss of a unique human genome. No ethical complications to do with plant meristems
How do stem cells treat Parkinson’s?
Replacing dead nerve cells with living, dopamine-producing ones
How does yeast redroduce?
Via budding
