Characteristics of Living Organisms & Nutrition/Respiration

Flashcards covering the defining characteristics of living organisms, distinctions between autotrophic and heterotrophic nutrition, and key facts about respiration.

What acronym summarises the 8 life processes required to classify something as living?

MRS C GREN (Movement, Respiration, Sensitivity, Control, Growth, Reproduction, Excretion, Nutrition).

List the 8 life processes represented by the acronym MRS C GREN.

Movement, Respiration, Sensitivity, Control, Growth, Reproduction, Excretion, Nutrition.

If an entity does NOT carry out all 8 MRS C GREN processes, how is it classified?

It is either dead or non-living.

Give an example of a non-living biological agent that fails the MRS C GREN test.

Viruses.

Why must organisms obtain food?

To provide energy needed to perform life processes such as movement, respiration and excretion.

How do plants obtain energy for life processes?

They manufacture glucose from sunlight, carbon dioxide and water via photosynthesis; this makes them autotrophic.

Why are plants described as autotrophic?

Because they create (feed) themselves by producing their own food through photosynthesis.

How do animals obtain their energy?

By consuming other organisms and digesting complex molecules into simpler ones; this makes them heterotrophic.

Why are animals described as heterotrophic?

Because they obtain food (‘feeding’) from different external sources rather than producing it themselves.

State the word equation for aerobic respiration.

Glucose + Oxygen → Carbon Dioxide + Water (+ energy transferred as ATP).

What are the two types of respiration mentioned and how do they differ?

Aerobic respiration uses oxygen; anaerobic respiration occurs in the absence of oxygen.

During respiration, in what molecular form is usable energy transferred?

ATP (adenosine triphosphate).

What waste products are generated by aerobic respiration?

Carbon dioxide and water.

Break down the word ‘autotroph’ into its Greek roots and meanings.

‘Auto’ = ‘self’, ‘trophic’ = ‘feeding’; together meaning ‘self-feeding’.

Break down the word ‘heterotroph’ into its Greek roots and meanings.

‘Hetero’ = ‘different’, ‘trophic’ = ‘feeding’; together meaning ‘different-feeding’, i.e., feeding on others.