CHapter 2.6 Specialised cells Flashcards
Define ‘tissue’
Collection of cells and their secretions that perform a common function
Define ‘organ’
Collection of tissues working together to perform a particular function
What is the xylem tissue compiled of?
Xylem vessels, parenchyma cells, dead cells
What is the phloem tissue compiled of?
Sieve tubes, companion cells
What does phloem carry?
Photosynthesis products
What does xylem carry?
Water
What are squamous epithelial cells for?
Line blood vessels and alveoli + sit on a basement membrane of collagen and glycoproteins
Where are ciliated epithelial cells found?
Trachea, bronchi and bronchioles
What are stem cells?
Unspecialised cells that renew themselves for long periods through cell division (mitosis)
Name the four types of stem cells
Totipotent, pluripotent, multipotent, unipotent
Outline what a totipotent stem cell is
Zygotes and early-stage embryos - can make all cell types
Outline what a pluripotent stem cell is
Capable of producing all cells derived from a particular layer eg. mesoderm, endoderm
Outline what a multipotent stem cell is
Can make a restricted range of related cell types eg. haemopoietic stem cells make RBC, WBC and platelets
Outline what a unipotent stem cell is
Able to make only one cell type eg. muscle stem cells
How long after fertilisation can embryonic stem cells be found?
3-5 day old embryos
Where can adult stem cells be found?
Bone marrow, muscles and brain
Generally, what type of stem cell are adult stem cells?
Multipotent
Give an example of what adult stem cells can treat
Leukemia
Give an example of what embryonic stem cells can treat
Parkinson’s
Give three ways that erythrocyte’s are adapted to their function
- Specialised for transport of O2
- Bio-concave shape, small shape to fit through capillaries
- Packed with haemoglobin
Outline three ways that neutrophils are adapted to their function
- Specialised for defence
- Phagocytosis of bacteria which are then digested
- Move to site of infection
How are squamous epithelial cells adapted to their function?
One cell thick to allow rapid diffusion of molecules eg oxygen
How are ciliated epithelial cells adapted to their function?
Cilia beat rhythmically to waft mucus upwards
goblet cells produce mucus to trap particles
How are sperm cells adapted to their function?
Tail for rapid movement, Many mitochondria for energy supply, acrosome on the head that contains enzymes to digest protective layers of the egg
How are palisade cells adapted to their function?
Thin walls increase rate of diffusion, Large vacuole to maintain turgor pressure, Lots of chloroplasts
How are guard cells adapted to their function?
Change shape to control loss of water
