Life Science

  1. What is life science? Life science is the study of living things and how they work. It tries to understand what life is, where it comes from, how it functions, and how living things interact with their surroundings and each other.

  2. What is life? Life refers to things that can:
    • Turn energy from their environment into usable energy (metabolism)
    • Make copies of themselves (reproduction)
    • Get bigger and more complex over time (growth and development)
    • Sense changes around them and react (response to stimuli)
    • Keep their internal conditions stable (homeostasis)
    • Change over time to survive better in their environment (adaptation)

  3. What are cells? Cells are the basic building blocks of all living things. They’re made up of different molecules like proteins, fats, DNA/RNA, and sugars. These molecules are arranged in ways that let the cell do things like use energy, grow, and reproduce. Some cells have a nucleus (a central control center), while others don’t.

  4. What are biochemical molecules? These are the main types of molecules that make up living things:
    • Proteins: Do most of the work in cells, like speeding up chemical reactions and giving cells structure
    • DNA: Stores genetic information, like a blueprint for making proteins
    • Lipids: Fats and oils that form cell boundaries and store energy
    • Carbohydrates: Sugars that provide energy and structure

  5. What is metabolism? Metabolism is all the chemical processes that happen in living things to keep them alive. It involves breaking down molecules to release energy and building up molecules to store energy. Cells use a molecule called ATP as a kind of energy currency.

  6. What is DNA and heredity? DNA is a molecule that stores genetic instructions. It’s made up of four building blocks arranged in a specific order, which tells cells how to make proteins. When living things reproduce, they pass copies of their DNA to their offspring. Sometimes small changes (mutations) occur in DNA, which can lead to new traits and drive evolution.

  7. What is evolution? Evolution is the process by which species change over time. It happens because:
    1. There are differences in genetic traits within a population.
    2. Some individuals have traits that help them survive better in their environment.
    3. These individuals tend to have more offspring, passing on their helpful traits.
    4. Over time, these traits become more common in the population.

  8. Ecosystems and interdependence: Living things don’t exist alone. They live in communities called ecosystems, where they interact with each other and their environment. These interactions include eating each other, helping each other, and competing for resources. The flow of energy and recycling of nutrients are important for keeping ecosystems balanced.

  9. How life science works - the scientific method: Life scientists use a step-by-step process to study living things:
    1. They observe something interesting.
    2. They come up with a possible explanation (hypothesis).
    3. They test their explanation through experiments.
    4. If their explanation is supported by lots of evidence, it might become a broader theory.
    5. Some well-established ideas become scientific laws.
  10. Fundamental principles in life science: Life science has discovered some key ideas that explain how life works:
    • All living things are made of cells, and all cells come from other cells.
    • Species change over time through natural selection.
    • Information in cells flows from DNA to RNA to proteins.
    • There are rules for how traits are passed from parents to offspring.

In summary, life science tries to figure out what life is and how living things work.

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