Characteristics of life Flashcards
revision (20 cards)
What are the 7 characteristics of life?
Movement, Respiration, Sensitivity, Growth, Reproduction, Excretion, Nutrition
What does unicellular mean?
An organism made of a single cell.
What does multicellular mean?
An organism made of many cells.
Name the five kingdoms of life.
Animalia, Plantae, Fungi, Protista, Prokaryotae.
What is the correct order of biological organisation from smallest to largest?
Organelle → Cell → Tissue → Organ → Organ system.
Why can unicellular organisms rely on diffusion alone?
Because they have a large surface area to volume ratio, making diffusion efficient.
Why do multicellular organisms need a transport system?
Because diffusion is too slow to meet the needs of all cells in a larger body.
What is diffusion?
The movement of particles from an area of higher concentration to an area of lower concentration.
How is the agar jelly practical used to demonstrate diffusion?
It shows how acid diffuses into jelly cubes, changing colour to represent how diffusion slows as size increases.
What is the function of the nucleus?
It contains DNA and controls the cell’s activities.
What is the function of mitochondria?
They carry out aerobic respiration to release energy.
What is the function of the cell membrane?
It controls the movement of substances in and out of the cell.
Name three structures found in plant cells but not in animal cells.
Cell wall, chloroplasts, and large central vacuole.
What is the function of chloroplasts?
They carry out photosynthesis.
What is the function of ribosomes?
They synthesize proteins.
How is a red blood cell adapted for oxygen transport?
Biconcave shape, no nucleus, contains haemoglobin.
What is the function of the cell wall?
Provides structure and support to plant cells.
What does the vacuole do?
Stores nutrients and helps maintain cell shape in plants
What is a prokaryotic cell?
A cell without a nucleus, such as bacteria.
Name two differences between prokaryotic and eukaryotic cells.
Prokaryotic cells lack a nucleus and membrane-bound organelles; eukaryotic cells have both.
