. Numerate and describe the characteristic features of life
The characteristic features of life can be summarized using the acronym "MRS GREN" (Movement, Respiration, Sensitivity, Growth, Reproduction, Excretion, and Nutrition). Let's delve into each of these features:
1. Movement: Life forms exhibit self-generated movement in response to stimuli. This includes moving individual body parts or locomotion as a whole. For example, animals move by utilizing muscles and skeletons, while plants exhibit growth movement through tropisms.
2. Respiration: Organisms need to obtain energy by taking in oxygen and releasing carbon dioxide. They perform respiration to convert nutrients into energy through different biochemical processes, such as cellular respiration in animals and photosynthesis in plants.
3. Sensitivity: Life forms have the ability to sense and respond to stimuli from their environment. They possess sensory organs or receptors that allow them to detect and interpret changes in their surroundings. This includes responding to light, sound, temperature, touch, taste, and smell.
4. Growth: Living organisms exhibit growth over time. They increase in size, develop new body parts, and undergo changes in structure and complexity. Growth is achieved through cell division and cell enlargement, resulting in an increase in the number and size of cells.
5. Reproduction: Reproduction is the process by which living organisms produce offspring. It ensures the continuity of life. There are two types of reproduction - asexual and sexual. Asexual reproduction involves the production of offspring without the involvement of gametes, while sexual reproduction involves the fusion of gametes from two parents.
6. Excretion: Living organisms produce waste products as a result of metabolic activities. These waste products, such as carbon dioxide, urea, and feces, need to be eliminated from the body to maintain homeostasis. Excretion enables the removal of these waste materials.
7. Nutrition: Organisms require nutrients to acquire energy for their survival and growth. They obtain these nutrients through various methods, such as photosynthesis in plants, ingestion in animals, or absorption in fungi. Nutrients include carbohydrates, proteins, lipids, vitamins, and minerals.
These characteristic features collectively define life and are present in diverse organisms, ranging from bacteria to complex animals.