Characteristics and Classification of Living Organisms
Each subtopic includes About section, revision page link, 10 preview questions, and practice CTAs.
Characteristics of living organisms
SubtopicCharacteristics of living organisms under Characteristics and Classification of Living Organisms for Grade 12 IGCSE.
Preview questions (no answers)
- 1.
Which characteristic allows an organism to adjust to changes in its surroundings?
A.Sensitivity
B.Respiration
C.Growth
D.Nutrition
- 2.
Which process is an example of excretion in plants?
A.Loss of water vapor from leaves
B.Production of seeds
C.Growth of roots towards water
D.Taking in carbon dioxide for photosynthesis
- 3.
What is the result of respiration in cells?
A.The creation of glucose
B.The release of chemical energy
C.The absorption of mineral ions
D.The removal of undigested food
- 4.
Which of the following is a characteristic of all living organisms?
A.The ability to breathe through lungs
B.The ability to produce heat
C.The ability to reproduce
D.The ability to walk
- 5.
Which characteristic of living organisms is defined as the 'removal of toxic materials and substances in excess of requirements'?
A.Nutrition
B.Respiration
C.Excretion
D.Growth
- 6.
In many multicellular organisms, cells specialize to perform specific functions. The coordination of these cells to respond to a stimulus is part of:
A.Excretion
B.Nutrition
C.Sensitivity
D.Reproduction
- 7.
The synthesis of new protoplasm from nutrients is a key part of which process?
A.Respiration
B.Growth
C.Excretion
D.Movement
- 8.
Which of the following is the most accurate summary of the role of 'ATP' in the characteristics of living organisms?
A.It is a waste product of excretion.
B.It is the primary source of carbon for nutrition.
C.It provides the immediate energy currency for processes like movement, growth, and active transport.
D.It is a signaling molecule used in sensitivity to detect light.
- 9.
If an organism's 'Respiration' rate exceeds its 'Nutrition' rate over a long period, what will be the most likely effect on its 'Growth'?
A.Growth will increase because more energy is being released.
B.Growth will stop, and the organism will lose dry mass as it consumes its own reserves.
C.The organism will reproduce more quickly to ensure survival.
D.Excretion will stop to conserve the remaining nutrients.
- 10.
Which of these is a response of a living organism to an internal stimulus?
A.A plant leaf turning towards the sun.
B.A person's pupils constricting in bright light.
C.The release of insulin in response to high blood glucose levels.
D.A bird flying south for the winter.
Download the worksheet for Characteristics and Classification of Living Organisms - Characteristics of living organisms to practice offline. It includes additional chapter-level practice questions.
Concept and use of a classification system
SubtopicConcept and use of a classification system under Characteristics and Classification of Living Organisms for Grade 12 IGCSE.
Preview questions (no answers)
- 1.
Organisms that are multicellular and must ingest (eat) other organisms for food belong to which kingdom?
A.Plantae
B.Animalia
C.Fungi
D.Prokaryote
- 2.
Which group in the hierarchy would contain multiple Families?
A.Genus
B.Species
C.Order
D.Sub-species
- 3.
What happens to the number of shared characteristics between organisms as you move down from Kingdom to Species?
A.The number of shared characteristics increases
B.The number of shared characteristics decreases
C.The number of shared characteristics stays the same
D.Shared characteristics are only found in Kingdoms
- 4.
Which kingdom includes organisms like yeast and mushrooms?
A.Plantae
B.Protoctista
C.Fungi
D.Prokaryote
- 5.
In the binomial system, which name is written first?
A.The species name
B.The order name
C.The genus name
D.The family name
- 6.
Which of the following organisms are classified as Protoctists?
A.Yeasts and mushrooms
B.Bacteria and cyanobacteria
C.Amoeba and algae
D.Mosses and ferns
- 7.
How do the cell walls of plants and fungi differ?
A.Plants have chitin; fungi have cellulose.
B.Plants have cellulose; fungi have chitin.
C.Plants have protein; fungi have cellulose.
D.Plants have no cell wall; fungi have cellulose.
- 8.
In the classification of Kingdom Protoctista, which of the following is true?
A.It is a diverse group of eukaryotic organisms that do not fit into the plants, animals, or fungi.
B.All members are unicellular and autotrophic.
C.All members lack a nucleus but contain other membrane-bound organelles.
D.It only includes organisms that are pathogens to humans.
- 9.
What is the significance of 'cladistics' in modern classification?
A.It groups organisms based on shared derived characteristics to show evolutionary pathways.
B.It groups organisms primarily based on their ecological role in the food web.
C.It relies exclusively on morphological traits to determine species relationships.
D.It ignores molecular data in favor of fossil record evidence.
- 10.
Which group of arthropods is specifically characterized by having three pairs of legs and a body divided into a head, thorax, and abdomen?
A.Insects
B.Arachnids
C.Crustaceans
D.Myriapods
Download the worksheet for Characteristics and Classification of Living Organisms - Concept and use of a classification system to practice offline. It includes additional chapter-level practice questions.
Features of organisms
SubtopicFeatures of organisms under Characteristics and Classification of Living Organisms for Grade 12 IGCSE.
Preview questions (no answers)
- 1.
Which organelle, found in plant cells, is used to identify them as autotrophic organisms during classification?
A.Mitochondrion
B.Ribosome
C.Chloroplast
D.Nucleus
- 2.
What is the main aim of biological classification?
A.To give every animal a pet name
B.To reflect evolutionary relationships between organisms
C.To group organisms by where they live
D.To organize organisms by their color
- 3.
Which of the following is a feature found only in the mammal group of vertebrates?
A.External ears called pinnae
B.An internal skeleton
C.Laying eggs with shells
D.Scales on the skin
- 4.
Which term describes the ability of an organism to sense and react to a stimulus?
A.Sensitivity
B.Respiration
C.Movement
D.Growth
- 5.
A student uses the provided dichotomous key to classify an invertebrate found in damp soil. The organism has a long, cylindrical body divided into many repeating segments, but it lacks jointed legs. Which group is represented by 'Group X' in the key?
A.Nematodes
B.Molluscs
C.Annelids
D.Myriapods
- 6.
Which group of vertebrates is endothermic and has hair or fur?
A.Reptiles
B.Birds
C.Mammals
D.Amphibians
- 7.
What is the significance of the 'dry mass' when measuring the growth of an organism?
A.It includes the weight of the water inside the cells
B.It is more accurate because water content can fluctuate
C.It is only applicable to plants and fungi
D.It represents the total volume of the organism
- 8.
Which characteristic of DNA is most useful when using it to classify organisms that look very similar morphologically?
A.The sequence of nucleotide bases.
B.The double-helical structure.
C.The ratio of adenine to thymine.
D.The presence of a deoxyribose sugar.
- 9.
A biologists identifies a marine organism with a soft body, a muscular foot, and a radula used for feeding. Which phylum does this organism belong to?
A.Mollusca
B.Annelida
C.Arthropoda
D.Nematoda
- 10.
Which of the following is true regarding the classification of the Kingdom Animalia?
A.All animals are multicellular heterotrophs that lack cell walls.
B.All animals possess a vertebral column at some stage of their life.
C.All animals reproduce solely through sexual reproduction.
D.All animals have a nervous system with a centralized brain.
Download the worksheet for Characteristics and Classification of Living Organisms - Features of organisms to practice offline. It includes additional chapter-level practice questions.
Dichotomous keys
SubtopicDichotomous keys under Characteristics and Classification of Living Organisms for Grade 12 IGCSE.
Preview questions (no answers)
- 1.
If a key asks if an organism has an 'exoskeleton', which large group of animals is being considered?
A.Vertebrates
B.Arthropods
C.Mammals
D.Amphibians
- 2.
Which level of classification is usually the goal of a detailed dichotomous key used in the field?
A.Kingdom
B.Phylum
C.Class
D.Species
- 3.
Which of these pairs represents a clear, objective choice for a dichotomous key?
A.1a. Animal is pretty; 1b. Animal is ugly
B.1a. Animal has wings; 1b. Animal lacks wings
C.1a. Plant is tall; 1b. Plant is short
D.1a. Leaf is large; 1b. Leaf is small
- 4.
In a dichotomous key for fungi, which feature might be used to distinguish between different types?
A.The presence of a cap and stalk
B.The color of the flowers
C.The number of legs
D.The type of wings
- 5.
A key for Identifying vertebrate classes includes the statement: 'Body covered with dry scales'. Which two classes would this help distinguish if the other option is 'Body covered with moist skin'?
A.Mammals and Birds
B.Reptiles and Amphibians
C.Fish and Reptiles
D.Amphibians and Fish
- 6.
In a key to identify reptiles, which characteristic would uniquely separate turtles from snakes and lizards?
A.Presence of a bony shell
B.Laying of eggs
C.Cold-blooded metabolism
D.Presence of scales
- 7.
A dichotomous key for microbes starts with '1a. Cell has a nucleus... go to 2' and '1b. Cell lacks a nucleus... go to 3'. Which organism would be found by following path 1b?
A.Amoeba
B.Yeast
C.Bacteria
D.Euglena
- 8.
Why are 'larval characteristics' rarely used in dichotomous keys for adult insect identification?
A.Holometabolous insects undergo complete metamorphosis, changing their morphology entirely.
B.Larvae do not have DNA, so they cannot be classified using the same keys.
C.Larvae belong to a different kingdom than the adult insects.
D.The IGCSE curriculum only requires the identification of vertebrate larvae.
- 9.
Which of the following describes the correct use of a dichotomous key in a laboratory setting?
A.Always start at the first couplet for every new specimen being identified.
B.Skip to the couplet that looks most familiar based on your prior knowledge.
C.Only use the key if you cannot identify the organism by looking at a photograph.
D.Start from the middle of the key to save time and work backwards.
- 10.
In a key for the class Mammalia, which characteristic would best separate Monotremes from Marsupials and Placental mammals?
A.The laying of leathery eggs instead of giving birth to live young.
B.The presence of hair or fur on the body surface.
C.The ability to produce milk from mammary glands.
D.The presence of a middle ear with three small bones.
Download the worksheet for Characteristics and Classification of Living Organisms - Dichotomous keys to practice offline. It includes additional chapter-level practice questions.