Cells, tissues and organs

plant and animal cells all have: 

• a nucleus--> to control the cells activities

• cytoplasm--> where chemical reactions take place

• a cell membrane--> controls the movement of materials in & out the cell

• mitochondria--> where energy is released during respiration

• ribosomes--> where protein synthesis takes place

• dissolved substances can be moved in and out of cells by diffussion.
• diffusion occurs rapidly when there is a larger difference in concentration
• diffusion is the net movement of particles from an area of high concentration to an area of low concentration
• examples of diffusion is: in the body for respiration (oxygen into cells), diffusion of CO2 in photosynthesis, diffusion of simple sugars from the gut

• tissue--> a group of cells with a similar structure and function
• different cells have different functions
• muscle tissue--> contract to bring movement
• glandular tissue--> provides substances like hormones and enzymes
• epitheral tissue--> covers some parts of the body

Plant tissue

• epidermal tissue--> covers some part of the plant
• mesophyll--> can photosynthesise
• xylem and phloem--> transport substances around the plant

• groups of organs work together in an organ system
• the food we eat must be converted from insoluble to soluble molecules so we can absorb them into our blood

The Digestive System-->

• pancreas- supplies digestive juices
• stomach and small intestines- where digestion occurs
• liver- produces bile
• small intestine-- absorption of soluble foods
• large intestine-- water is absorbed