Biology: 1a-Characteristics of Living Organisms

What are all living organisms broadly classified into based on the number of cells?

Unicellular and Multicellular

Give some examples of unicellular organisms

bacteria, protozoa, yeast, amoeba

Give some examples of multicellular organisms

plants, animals

Name the acronym that all living organisms exhibits and their meanings.

M - ovement

R - eproduction

S - sensitivity

H - omeostatis

G - rowth

R - espiration

E - xcretion

N - utrition

What is movement?

The action of an organism that causes a change in position or place.

What is movement of an organism from place to place called?

locomotion

What are the movement of plants? Give an example

plants can change their orientation, which helps them carry out photosynthesis. E.g. The leaves of a plant moves towards the direction of light and the roots grows downwards to find water and mineral ions in soil.

What is respiration?

Respiration is the chemical reaction that takes place in cells of all living things.

Respiration can take place...

With oxygen = aerobic respiration

Without oxygen = anaerobic respiration

What is the word equation for aerobic respiration?

Glucose + oxygen -> carbon dioxide + water + ATD/Energy

What is ATP?

Adenosine triphosphate is the 'energy currency' of a cell. Energy released during respiration carries out processes like growth.

What is sensitivity?

the ability to detect and respond to stimuli (changes) in its surroundings.

give some examples of senstivity

Animals: Have nervous systems that contain receptors, neurones and effectors. Has Endocrine (hormonal system).

Plants: Geotropism which is the response to gravity as the roots grow towards gravity and shoots grow against gravity. Phototropism responses to light and cause plants to grow towards or away form a light source.

What is Homeostasis

The maintenance of a constant internal environment.

Why is homeostasis important??

Maintains optimal conditions for cell function and enzyme activity.

What is growth

The permanent increase in cell size, cell number, or cell complexity.

Why is growth important?

it increase the likelihood of survival.

What is reproduction?

The process where living organisms produce offspring.

What are the two types of reproduction?

Asexual reproduction: Only one parent is needed to produce an offspring, offspring is genetically identical to the parent/.

Sexual reproduction: Two parents of the opposite sex are needed to produce an offspring, offspring is genetically different to the parent.

What is excretion?

the removal of waste substances, metabolic reactions, metabolic reactions, toxic materials and substances produced in excess if requirements.

What is a metabolic reaction?

A chemical reaction that takes place inside the living cells. These toxic products much be eliminated form the body.

What waste products do animals produce?

Carbon dioxide from respiration (exhaled by lungs), Urea from the breakdown of proteins.

What waste products to plants produce?

Carbon dioxide from respiration (released by stomata- tiny openings on the underside of leaves) and water from respiration (released as water vapour by stomata).

What is nutrition?

The process of obtaining food for energy and nutrients

How to animals and plants obtain nutrition?

Animals: Consuming other organisms, classified as heterotrophs.

Plants: Make their own food (glucose) during photosynthesis, classified as autotrophs.