3.5 Cell specialisation and organisation

Question 1

What is a tissue? List examples.

Answer 1

a collection of similar cells that perform a specific function.
examples include:
-epithelial tissues (in animals, line surfaces or organs for protective or secretory funtions)
-xylem (in plants, transport water and mineral ions and offer mechanical support

Question 2

What is an organ? List examples.

Answer 2

a combination of tissues, coordinated to perform a variety of functions and typically a predominant function.
examples include:
-the stomach (involved in digestion, consisting of muscle to churn contents, epithelium to protect walls and secrete, connective tissue to hold other tissues together)
-leaves (for photosynthesis, consisting of palisade mesophyll for photosynthesis, spongy mesophyll for gaseous diffusion, phloem to transport organic materials away, xylem to transport water and ions into organ)
-arteries and veins (blood transport, consisting of epithelial and muscle tissue, amongst others)

Question 3

What is an organ system? List examples

Answer 3

collection of organs grouped together to perform particular functions
examples include:
-digestive system (digest and process food, organs include salivary glands, oesophagus, stomach, duodenum, ileum, pancrease, liver)
-respiratory system (breathing and gas exchange, organs include the trachea, bronchi, lungs)
-circulatory system (pumps and circulates blood, organs include the heart, arteries, veins)