Squamous and epithelial tissue - lines free surfaces of the body such as skin, respiratory and digestive systems and blood vessels. Almost made entirely out of cells which are very close to each other - forms continuous sheets. No blood vessels - receive nutrients via diffusion. Some contain cilia or microvilli. Short cell cycles - replace damaged tissue. Specialised to carry out function.
Cartilage - immature cells (chondroblasts) divide by mitosis and secrete the extracellular matrix and then mature. Matrix maintained by less active chondrocytes. Hyaline cartilage - forms embryonic skeleton, covers ends of long bones in adults, joins ribs to sternum, found in nose, trachea and larynx. Fibrous cartilage - between discs between vertebrae and in knee joint. Elastic cartilage - outer ear and epiglottis.
Muscle tissue - well-vascularised, made of elongated fibres which contain myofilaments which allow muscle to contract. Skeletal muscle - packaged by connective tissues, joined to bones by tendons and causes bones to move. Cardiac muscle - makes up heart walls and allows heart to beat. Smooth muscle - occurs in intestine walls, blood vescles, uterus and urinary tract and propels substances along these tracts.
Xylem - carry water and minerals from plant roots to all parts of plant. Lignin is deposist in the cambium cell walls which reinforces them, waterproofs them and kills the cells. The ends of the cells break down and form continuous coloumns with wide lumens.
Phloem sieve tubes - transfer products of photosynthesis in solution, from leaves to parts of the plants that do not photosynthesise such as roots, flowers and shoots. Not many organelles. Sieve plates form between the cells. Companion cells retain their organelles and continue metabolic functions to provide ATP for active loading of sugars into phloem.

	Criado por Zoe Mitchell quase 10 anos atrás

A level Biology (Module 2: Foundations in Biology) Slides sobre 2.1.6 Cell division, cell diversity and cellular organisation, criado por Zoe Mitchell em 30-12-2016.