The Characteristics of Life Flashcards
Define organism
An organism is a living thing.
Define metabolism
Metabolism is the sum of all the chemical reactions in an organism.
Metabolic reactions are controlled by chemicals called _______
Enzymes
Define continuity of life
Continuity of life means that living things arise from other living things of the same type.
Define life
Life is defined as the possession of all the following characteristics: organised, requiring nutrition and excretion, capable of responding and reproducing.
Why are the five characteristics of life necessary?
The five characteristics of life are necessary for organisms to maintain their metabolism and continuity of life. In particular, these characteristics allow organisms to carry out all the reactions necessary to survive and reproduce.
What are the five characteristics of life?
- Organisation
- Nutrition
- Excretion
- Response
- Reproduction
Define organisation
Organisation means that living things are composed of cells, tissues, organs and organ systems.
Give two examples of unicellular organisms.
- Bacteria
- Amoeba
Give two examples of multicellular organisms.
- Trees
- Humans
Define nutrition
Nutrition is the way in which an organism obtains and uses food.
Why is food needed?
Food is needed for energy and to supply the materials needed for normal life.
Define excretion
Excretion is the removal of waste products of metabolism from the body.
Why do plants have less need for excretion than animals?
Plants have less need for excretion than animals because they make their own food and do not produce or take in as much waste.
What are the excretory structures present in humans?
- Skin
- Lungs
- Urinary system (kidneys and bladder)
What are the main products excreted in advanced animals?
- Carbon dioxide
- Salts
- Surplus water
Define response
Response is the way in which all living things react to changes in their environment.
What is response also known as?
Behaviour
How do plants move?
Plants move by changing their growth, e.g. stems bend towards light, roots grow down into the soil towards gravity and leaves turn to face the sun.
Define reproduction
Reproduction is the production of new individuals.
Define sexual reproduction
Sexual reproduction is a type of reproduction where two parents produce offspring that are not genetically identical to the parents.
Define asexual reproduction
Asexual reproduction is a type of reproduction where only one parent is involved and the offspring is genetically identical to the parent.
