biology

• The nucleus is the control center of the cell, containing the genetic material.
• double ciruculation

  blood passes thru the heart thru lungs to body and back to heart
• effect of physical activity on heart

  heart beats more quickly and more deeply, an increased circulation of blood so that more oxygen and glucose can get to the muscles
• xylem


  transports water and mineral ions
• phloem


  sucrose and amino acids
• adaptations of xylem

  thick walls w lignin

  no cell contents
• root hair cell structure

  have an elongated shape for more surface area which increase the rate of absoprtion of water by osmosis and ions by active transport
• pathway taken by water

  water enters root hair cells from moist soil via osmosis

  bc water potential is higher in soil than cytoplasm

  water passes thru the cortex cells by osmosis

  water enters xylem then leaves when it gets to mesophyll cells
• what is transpiration

  is the loss of water vapour from leaves