Energy stores, energy sources, energy in food

• Chemical energy is the energy stored in the bonds of molecules.
• Kinetic energy is the energy of motion.
• Explanation of why a light bulb wastes some electrical energy
• Five main ways in which energy is transferred:

  • Light
  • Sound
  • Heat (thermal)
  • Movement (kinetic)
  • Electricity
• Reason for using kilojoules to measure energy in food
• Chemical energy is stored in chemical form such as batteries, fossil fuels or food
• Elastic potential energy is stored in a stretched elastic material and when released, it is usually transferred to kinetic energy (movement)
• Example of elastic potential energy transfer to kinetic energy
• Gravitational potential energy (GPE) is stored in something lifted up against gravity and when it falls, GPE is transferred to kinetic energy (movement)
• Example of gravitational potential energy transfer to kinetic energy
• Table of pros and cons for using non-renewable and renewable fuels to generate electricity
• Energy can be transferred from one place to another but cannot be created or destroyed.
• adolescence


  Time when both physical and emotional changes occur in humans
• afterbirth


  When the placenta is pushed out through the vagina
• amnion


  Bag containing amniotic fluid
• amniotic fluid


  Liquid surrounding the growing embryo and protecting it
• antibodies


  Substances produced by white blood cells that help to fight microbes which might cause diseases
• cilia


  Small hairs on the surface of some cells
• contractions


  The uterus starts to push out the baby during labour
• cord


  Carries food, oxygen and waste between the placenta and the growing fetus
• egg cell


  The female sex cell in plants
• ejaculation


  Semen is pumped out of a man's penis into the top of the vagina during sexual intercourse
• embryo


  Tiny plant, found inside a seed, with a very small shoot and a very small root
• erection


  When the penis becomes stiff
• external fertilisation


  When fertilisation happens outside the bodies of the parents
• fertilisation


  Joining of a male sex cell with a female sex cell
• fertilised egg cell


  What is produced when a male sex cell fuses with an egg cell
• foetus


  After an embryo has grown all its organs it is called a fetus. This is usually at about 10 weeks
• fuse


  When two sex cells join together to form a fertilised egg cell they are said to fuse
• gestation period


  The length of time from fertilisation to birth
• glands


  The glands in the male reproductive system add a special liquid to the sperm cells to make semen. There are other sorts of glands in the body
• implantation


  When an embryo sinks into the soft lining of the uterus
• internal fertilisation


  When fertilisation happens inside the bodies of the parents
• labour


  Time when the baby is about to be born
• mammary glands


  Glands contained in the breasts of women which produce milk after childbirth
• menopause


  When the ovaries in women stop releasing eggs
• menstrual cycle


  Series of events lasting about a month, happening in the female reproductive system. The cycle causes ovulation and the lining of the uterus is replaced
• menstruation


  When the lining of the uterus and a little blood pass out of the vagina as part of the menstrual cycle
• navel


  Scar left by the cord. Often called the 'belly-button'
• nucleus


  Controls what a cell does