MRSGREN, Broken Down

Movement

In order for an organism to be classed as living, it needs to be able to move. Although some organisms are almost immovable, they have a level of self-powered movement. Plants fall into this category, as although they don't physically move, they can to a degree, through phototropism.

Movememt is important from an evolution perspective. If movement doesn't occur, it decreases chances of catching prey, or being caught themselves.

Respiration

The conversion of energy from carbohydrates and fats into energy which is in turn used by cells. Multi-cellular organisms (such as yourself, and animals) use respiration with oxygen to break down sugars, and carbon dioxide is created as a by-product (usually exhaled). Other microorganisms use iron or nitrates instead of oxygen in oxygen-depleted areas.

Sensitivity

How an organism responds to an environment, depends on its sensitivity. All organisms can sense change in their environment, and react when something changes. For example, clam shell type crustaceans such as barnacles and oysters will close up when the tide is low, to prevent them from drying out.

Control

Based around homeostasis, which is the control of balance within an organism, control is exactly that. Every organism has some level of control in their own environment of cells and body. It needs to be maintained, and in order to do this, there are a set of controls that limit or keep the balance of regulation.

Growth

Organisms need to grow. Plants for example, will grow from small seeds, cuttings or bulbs, and then when they grow they reproduce in some manner. Growth is essential for an organism. Each organism uses energy in order to grow.

Reproduce

Like said above, once grown, an organism will reproduce. Sometimes this is a quick process, with seeds being flung (like a poppy head) in the wind, or sometimes it can take a long gestation period (elephants take up to 2 years to fully birth a baby). There are different ways that reproduction occurs - sexually, or a asexually. It all involves genetic materials that pool for variation or the ability to clone.

Excretion

An organism will create waste material. Simple as that, an organism that is living will create waste and will need to excrete it. We humans create feces, which are excreted through the end of the digestive system. Other animals do the same, in slightly different ways, and even plants are able to do similar.

Nutrition

The final component of MRSGREN, nutrition is needed for each organism to survive, grow and reproduce. This is in the form of food, energy and nutrients. For plants, this will include gaining nutrients from underground, as well as sunlight. For animals and humans, this can include consuming producers such as grass and vegetation, or other consumers like cows or small animals.

Link to DNA

Without DNA, MRSGREN would also not work. Whether the organism is small or large, it carries DNA with it. And when it reproduces, it will use DNA from the gene pool given to it by it's predecessor. DNA is a vital part of an organism. Though, virsuses carry DNA, it still is not classed as a living organism. But DNA is one of the most important parts of an organism.