Not needed to stay alive
Reproduction is different from the life processes.
One lone organism
Imagine one organism that eats food, breathes and gets rid of its wastes, but never makes any young ones.
Can this one organism stay alive?
What this lesson covers
The idea
Unlike life processes such as nutrition, respiration or excretion, reproduction is not necessary to maintain the life of an individual organism, and it uses up much of the organism's energy.
One lone organism
Imagine one organism that eats food, breathes and gets rid of its wastes, but never makes any young ones.
Can this one organism stay alive?
- Yes, it can stay alive
- No, it cannot stay alive
- It can stay alive only if it reproduces
Sort the processes
Drag each card to the group where it belongs. Think about what keeps ONE individual alive.
What reproduction costs
Nutrition, respiration and excretion are essential life processes. The individual needs them to stay alive. Reproduction is different. The individual can stay alive without it. And if it makes more individuals, a lot of its energy is spent.
Unlike life processes such as nutrition, respiration or excretion, reproduction is not necessary to maintain the life of an individual organism, and it uses up much of the organism's energy.
Notes
Reproduction is not necessary to keep an individual alive, unlike nutrition, respiration and excretion, and it uses up much of the organism's energy.
Check yourself
Which of these is NOT needed to keep one individual organism alive?
What does making new individuals cost the parent organism?
A student says, "An animal that never reproduces will not stay alive." What is the right reply?
- Respiration. Respiration is an essential life process, so the individual needs it.
- Reproduction — correct. Yes!
- Nutrition. Nutrition is an essential life process, so the individual needs it.
- Nothing, because it costs no energy. The book says that creating more individuals spends a lot of the organism's energy.
- It saves energy for the parent. It is the opposite: a lot of the parent's energy is spent.
- A lot of its energy — correct. Yes!
- Reproduction is not necessary to maintain the life of an individual — correct. Yes!
- Reproduction is an essential life process, like respiration. The essential life processes named in the book are nutrition, respiration and excretion. Reproduction is not necessary for the individual's life.
- It would die at once because it has no young ones. Reproduction is not necessary to maintain the life of an individual organism.