Biology

  1. What is biology? Biology is the study of living things. It tries to understand what makes something alive, how living things work, and how they interact with each other and their surroundings.

  2. What is life? Life is what separates living things from non-living things. Some key features of life include:
    • Organization: Living things have complex structures, from tiny parts to whole bodies.
    • Metabolism: Living things can take in energy, change it, and use it to stay alive.
    • Homeostasis: Living things can keep their insides stable, like maintaining body temperature.
    • Growth and development: Living things get bigger and change over time.
    • Reproduction: Living things can make more of themselves.
    • Response to stimuli: Living things can sense and react to changes around them.
    • Evolution: Groups of living things can change over long periods of time.
  3. What is a cell? A cell is the smallest unit of life. All living things are made of one or more cells. There are two main types:
    • Simple cells (prokaryotic): These don’t have a central compartment for DNA.
    • Complex cells (eukaryotic): These have a central compartment for DNA and other specialized parts.

    Cells have some basic parts:

    • A membrane that separates the inside from the outside
    • A jelly-like substance inside (cytoplasm)
    • DNA, which contains instructions for the cell
    • In complex cells, specialized structures that do specific jobs
  4. What is DNA? DNA is like a instruction manual for living things. It’s made up of small pieces called nucleotides. These pieces form a twisted ladder shape. DNA:
    • Contains instructions for how living things grow and work
    • Can be copied and passed down when living things reproduce
    • Can change over time, which leads to evolution
  5. What is evolution? Evolution is how groups of living things change over time. This happens because:
    • Individuals in a group are slightly different from each other.
    • Some individuals are better suited to their environment and are more likely to survive and have offspring.
    • Random changes in DNA can create new traits.
    • Different groups can mix and share traits.
    • In small groups, traits can become more or less common by chance.

    Evolution explains why there are so many different types of living things and how they become suited to their environments.

  6. What is metabolism? Metabolism is all the chemical reactions that happen inside living things to keep them alive. There are two main types:
    • Breaking down substances to release energy
    • Building up substances using energy

    Living things get energy from different sources, like sunlight or food. They use a special energy-carrying molecule called ATP to power many of their functions.

  7. What is homeostasis? Homeostasis is how living things keep their insides stable. This includes:
    • Keeping the right temperature
    • Maintaining the right balance of acidity
    • Controlling the amount of water and important minerals

    Homeostasis is crucial for survival. It involves systems in the body that constantly check and adjust internal conditions.

  8. Reproduction and genetics: Reproduction is how living things make more of themselves. There are two main types:
    • Asexual reproduction: One parent makes an identical copy of itself.
    • Sexual reproduction: Two parents combine their genetic material to make offspring with a mix of traits.

    Genes are sections of DNA that carry instructions for specific traits. These traits are passed from parents to offspring.

  9. Ecosystems and ecology: An ecosystem includes all the living things in an area and the non-living parts of their environment. In ecosystems:
    • Energy flows from plants (which make food using sunlight) to animals and decomposers.
    • Important substances like carbon, nitrogen, and water cycle through the system.
    • Living things often form relationships with each other, which can be beneficial, neutral, or harmful.

In summary, biology is about studying life, from the tiniest parts of living things (cells) to how different living things interact with each other and their surroundings.

Table of contents