Life Processes Flashcards

Flashcards about life processes based on lecture notes.

What are life processes?

The processes which perform the maintenance job in living organisms, even when they are asleep.

What is nutrition?

The process of transferring a source of energy (food) from outside the body to the inside of an organism.

Why is oxygen important for many organisms?

Many organisms use oxygen sourced from outside the body in oxidising-reducing reactions to break down molecules for energy.

What is respiration?

The process of acquiring oxygen from outside the body and using it to break down food sources for cellular needs.

Why is a transportation system needed in multi-cellular organisms?

To carry food and oxygen from one place to another in the body, since not all cells are in direct contact with the surrounding environment.

What is excretion?

The process by which waste by-products are removed from the body and discarded outside.

What are autotrophs?

Organisms that use simple food material obtained from inorganic sources like carbon dioxide and water (e.g., green plants and some bacteria).

What is the role of enzymes in heterotrophs?

Enzymes are bio-catalysts used by heterotrophs to break down complex substances into simpler ones for upkeep and growth.

What is photosynthesis?

The process by which autotrophs convert carbon dioxide and water into carbohydrates in the presence of sunlight and chlorophyll.

What is the function of stomata?

Tiny pores on the surface of leaves that facilitate massive amounts of gaseous exchange for photosynthesis.

How do guard cells control the opening and closing of stomatal pores?

Guard cells swell when water flows into them, causing the stomatal pore to open, and shrink to close the pore.

How do terrestrial plants obtain water and other raw materials?

Water is taken up from the soil by the roots, while other materials like nitrogen, phosphorus, iron, and magnesium are also absorbed from the soil.

What are heterotrophs?

Organisms that obtain nutrition from other plants or animals and break down food material either outside or inside their bodies.

What is a food vacuole?

A structure in single-celled organisms like Amoeba where food particles are enclosed and broken down into simpler substances.

What is the alimentary canal?

A long tube extending from the mouth to the anus in human beings, specialized into different regions to perform different functions in digestion.

What is the role of saliva in digestion?

Saliva contains the enzyme salivary amylase, which breaks down starch into simple sugar.

What is the function of peristaltic movements?

Rhythmic contractions of muscles in the lining of the digestive canal that push food forward.

What is the role of hydrochloric acid in the stomach?

Creates an acidic medium for the enzyme pepsin to function and helps to protect the inner lining of the stomach.