B1 Part 2



1) Diffusion is the spreading out of particles from an area of higher concentration to an area of lower concentration

2) Oxygen and Carbon Dioxide diffuse during gas exchange in the lungs

3) Factors that affect the rate of diffusion are:

  • Concentration gradient
  • Temperature
  • Surface area of the membrane

4) Because the substances move from an area of high concentration to an area of low concentration

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Osmosis and Active Transport

1) The movement of water molecules across as a partially permeable membrane from a region of high water concentration to a region of low water concentration

2)  Red blood cells will swell up and burst when put in water with a high concentration

When plant cells are placed in a high water concentration it takes up water but the cell wall stops it from bursting so it becomes turgid instead

3) The red blood cells will swell up in the solution as they are usuing osmosis to take the water in

4) Active transport is the movement of of a substance from an area of low concentration to an area of high concentration

Active transport happens in respiration in animals and in plants active transport is used to take up mineral ions the root hair cell.

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1) Chromosomes- molecules found in the nucleus of all cells; made from DNA

   Gene- Part of a chromosone, made of DNA, which codes for a protein

   Allele- an alternative form of a particular gene

2) One chromosone is from the molther one is from the father

3) It's a female because they have two x chromosomes

4)  DNA is the chemical that all genetic material is made up of. DNA is found in the nucleus of animal and plant cells in long structures called chromosomes.

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Cell Division

1) Mitosis:

  • The chromosomes duplictae 
  • The nucleus divides
  • The cytoplasm and cell membrane divides
  • There is now two identical copies of a cell

2) 2 identical daughter cells to the parent cells are produced in mitosis                                          3) Cells divide to replace old or dead cells with new fresh ones                                                        4) Stem cells are used to cure diseases and they can also be used to replace faulty cells. However there are risks of the cells being contaminated with a virus that could pass on as they are grown in a lab.                                                                                                                                                  5) Stem cells are undifferentiated cells that can divide to produce more undifferentiated cells. There are embryonic and adult stem cells. Stem cells are found are found in early human embryos or bone marrow.                                                                                                                                    6)The cell cycle is a cycle of stages that cells pass through to allow them to divide and produce new cells. The cell prepares by gathering nutrients and making a copy of its DNA.

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