Multicellular organisms

Multicellular organisms
- Producing new cells
  Cell division allows for growth and replacement of dead cells. Most multicellular organisms are made of different cell types that are specialised to carry out specific functions.
- Control and communication
  Communication between cells in a multicellular organism occurs by use of nerve impulses or hormones. The central nervous system produces electrical impulses for rapid response.
- Reproduction
  New organisms are produced when male and female haploid gametes fuse. In mammals, gametes are produced in the testes or ovaries of individuals but anthers and ovaries are on the same flowering plant.
- Variation and inheritance
  The phenotype for a characteristic like eye colour is the result of the combination of alleles. If the alleles in the parental genotype are dominant or recessive, probable outcomes can be predicted.
- Transport systems - Plants
  Multicellular organisms require transport systems to supply their cells and remove waste products. Plants transport substances through xylem and phloem.
- Transport systems - Animals
  Multicellular organisms require transport systems to supply their cells and remove waste products. The heart uses blood vessels to transport these substances around the body.
- Absorption of materials
  Humans require transport systems to supply their cells and remove waste products. Gas exchange occurs in the lungs and food molecules are absorbed by the digestive system.
Video playlist
- Specialised and non-specialised cells. Video
  Comparing the roles of specialised and non-specialised cells in both animals and plants.
- The digestive system. Video
  Animated description of the digestive process and the structures of the digestive system.
- Sexual reproduction in animals. Video
  The biological processes involved in the sexual reproduction of animals.
- Plant and animal cell structures. Video
  A look at the cells of different organisms and a comparison of structures.
- Van Helmont's experiments on plant growth. Video
  How Jan Baptist van Helmont showed that plants did not use soil to grow.
- Hormonal systems. Video
  Endocrine glands produce hormones that regulate conditions in the body.
- Skeletal muscles. Video
  Looking at the role of skeletal muscles in moving parts of the body.
- Nervous system. Video
  The nervous system controls how the human body responds to sensory information.
- A balanced diet. Video
  An explanation of balanced diet and amounts of the food groups that make it up.
- Transport and exchange - Digestive system. Video
  Food is broken down and absorbed as it moves through the digestive system.
- Genetics. Video
  Genetic information in an organism's DNA controls its phenotype.
- The difference between cells, tissues and organs. Video
  An explanation of how cells make up tissues which in turn make up organs.
- Transport and exchange - Gas exchange. Video
  The movement and exchange of gas through the respiration system in animals.
- Transport and exchange in plants. Video
  The movement of water, nutrients and gases through a plant.
- Sexual reproduction in plants. Video
  Sexual reproduction involves haploid gametes fusing to form a diploid zygote.
- Reproductive cycle of crabs. Video
  Professor Richard Fortey investigates the reproductive cycle of the crab.
- Transport and exchange - Blood circulation. Video
  The heart pumps blood around the body. Blood carries oxygen and nutrients.

Video playlist

Links