Characteristics of Living Organisms

These flashcards cover key concepts from the characteristics of living organisms, focusing on MRS GREN, processes like respiration and reproduction, and differences in growth and nutrition.

What does MRS GREN stand for in biology?

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

What is movement in the context of living organisms?

An action by an organism or part of an organism causing a change of position or place.

What is locomotion?

The movement of an organism from one place to another.

Can plants perform locomotion?

No, plants cannot perform locomotion, but they can change their orientation, such as through phototropism.

What is respiration?

The chemical reactions in cells that break down nutrient molecules and release energy for metabolism.

What are the products of aerobic respiration?

Carbon dioxide and water.

What is the difference between aerobic and anaerobic respiration?

Aerobic respiration occurs in the presence of oxygen, while anaerobic respiration occurs in its absence.

How does respiration differ from breathing?

Respiration is a chemical process that releases energy, not merely the act of breathing.

What is sensitivity in living organisms?

The ability to detect and respond to changes in the internal or external environment.

How do sensitivity mechanisms differ between humans and plants?

In humans, sensitivity is managed by the nervous system; in plants, it is controlled by slower chemical processes.

What does growth refer to in living organisms?

A permanent increase in size and dry mass.

How do animals and plants differ in their growth patterns?

Animals grow from the zygote to adult stages; plants grow throughout their entire life by adding new parts.

What is the process of reproduction?

The process that produces more of the same kind of organism, which is fundamental for survival.

What are the two types of reproduction?

Sexual reproduction (involving two parents) and asexual reproduction (involving one parent).

What is excretion?

The removal of waste products of metabolism and substances in excess of requirements.

How do humans excrete waste?

Through the skin, lungs, and liver.

How do plants excrete waste?

Plants remove different waste products at different times of the day.

What is nutrition in biology?

The process of taking in materials for energy, growth, and development.

What is autotropic nutrition?

The ability to create one's own food, as seen in plants through photosynthesis.

What is heterotropic nutrition?

The process of obtaining food from different sources, as seen in animals.

Give an example of organisms that reproduce sexually.

Plants, animals, and most fungi.

Give an example of organisms that reproduce asexually.

Bacteria, most protista, and a few fungi.

What happens during fertilization?

The fusion of an egg (ovum) and sperm, forming a zygote.