specialised cells, tissues, organs and systems 2.2

• • specialised cell

  there are many specialised cells in organism, this process for development is called differentiation
• differentiation is the process by which a cell becomes specialised for a specific function
• • red blood cell

  has no nucleus, enabling it to load more oxygen
• • red blood cell

  has a binocave, increase the surface area to volume ratio, oxygen can thus diffuse in and out more efficiently
• xylem vessel transport water from roots to the leaves
• • xylem vessel

  do not have a cross wall or protoplasm, this enables water and mineral salts to move through the lumen easily
• • xylem vessel substance

  called lignin is deposited in xylem vessels
• • xylem vessel structure

  lignin strengthens the xylem vessel and prevents the xylem from collapsing
• • xylem vessel function

  provides mechanical support for the plant
• • root hair cell

  is long and narrow, this increase the surface area to volume ration to absorb water and mineral salt efficently
• • how do cells work together in a multicellular organism?

  1. cells
  2. tissues
  3. organ
  4. organ system
• cells, specialised for a particular function
• tissues, a group of similar cells which work together to perform a specific function
• organ, different tissues working together to carry out a specific function
• organ system, several related organs working together to carry out a particular function
• there are 2 types types of tissue, simple tissue and complex tissue
• • simple tissue in animals

  are made up of only one type of cells, epithelial (skin) tissue and muscle tissue
• • simple tissue in plants

  epidermis
• • complex tissue in animals

  different cell types, connective tissue, nervous tissue, glandular tissue and bone tissue
• • complex tissue in plants

  vascular tissue
• • vascular tissue - xylem

  transport water from roots to stem and leaves and nutrients
• • vascular tissue - phloem

  transport and distribution of organic nutrients
• • organ

  different tissue may combine to form an organ to perform a specific function, group of tissues which work together to perform a specific function
• • organ in animals

  stomach, made up of many tissue and its function is to digest food
• • organ in plants

  leaf, made up of several tissue and its function is to photosynthesise
• • organ system

  different organs work together to form an organ system, a group of organs which work together to perform a specific function