CIE A Level Biology: Classification,
Biodiversity and Conservation Latest
Exam and All Correct Answers 2025-
2026 Updated.
What are species - Answer A group of organisms with similar morphological and
physiological features that able to breed together and produce fertile offspring
Morphological species concept - Answer In the past, most scientists described organisms by
their physical features (morphology) as these can be more easily observed, They group together
organisms that share many physical features that distinguish them from other species, This is
the morphological species concept
Ecological species concept - Answer When there is a population of similar organisms living in
the same area at the same time, they can be described as an ecological species. This is the
ecological species concept
Naming of species - Answer The first part of the name is the genus that the species belongs
to; this is a group of very similar organisms. The second part of the name is specific and unique
to a single group of organisms that are identified as a species (and occasionally there may be a
third name). e.g Saccharomyces cerevisiae
Taxonomy - Answer Taxonomy is the practice of biological classification
What is the highest rank in the hierarchical classification system - Answer The highest rank is
the domain
The different cell types - Answer Prokaryotic cells are easily distinguishable in that they lack
a nucleus
Eukaryotic cells have compartmentalised structures, with at least their genetic material
segregated from the rest of the cell in a nucleus
What are three domains - Answer Archaea (prokaryotes)
Bacteria (prokaryotes)
Eukarya (eukaryotes)
Features of archae - Answer Archael cells have no nucleus (and so are prokaryotic). They
were initially classified as bacteria until several unique properties were discovered that
separated them from known bacteria, including:
,Unique lipids being found in the membranes of their cells
No peptidoglycan in their cell walls
Ribosomal structure (particularly that of the small subunit) are more similar to the eukaryotic
ribosome than that of the bacteria
Archaea a similar size range as bacteria (and in many ways metabolism is similar between the
two groups)DNA transcription is more similar to that of eukaryotesExample: Halobacterium
salinarum are a species of the archaea domain that can be found in environments with high salt
concentrations like the Dead Sea
Features of bacteria - Answer These are organisms that have prokaryotic cells which contain
no nucleus. They vary in size over a wide range: the smallest are bigger than the largest known-
viruses and the largest are smaller that the smallest known single-celled eukaryotes. Bacterial
cells divide by binary fission
Example: Staphylococcus pneumoniae is a bacteria species that causes pneumonia
Features of eukarya - Answer Organisms that have eukaryotic cells with nuclei and
membrane-bound organelles are placed in this domain. They vary massively in size from single-
celled organisms several micrometres across to large multicellular organisms many-metres in
size, such as blue whales. Eukaryotic cells divide by mitosis, Eukaryotes can reproduce sexually
or asexually. Example: Canis lupus also known as wolves
Main differences between archae and bacteria - Answer Membrane lipids
Ribosomal RNA
Cell wall composition
How do archae and bacteria differ in their membrane lipids - Answer The membrane lipids
found in the cells of Archaea organisms are completely unique. They are not found in any
bacterial or eukaryotic cells, The membrane lipids of Archaea consist of branched hydrocarbon
chains bonded to glycerol by ether linkages. The membrane lipids of Bacteria consist of
unbranched hydrocarbon chains bonded to glycerol by ester linkages
How do archae and bacteria differ in their ribosomal RNA - Answer Both Archaea and
Bacteria possess 70S ribosomes, The 70S ribosomes in Archaea possess a smaller subunit that is
more similar to the subunit found in Eukaryotic ribosomes than subunits in Bacterial ribosomes.
The base sequences of ribosomal RNA in Archaea show more similarity to the rRNA of Eukarya
than Bacteria, The primary structure of ribosome proteins in Archaea show more similarity to
the ribosome proteins in Eukarya than Bacteria
How do archae and bacteria differ in their cell wall composition - Answer Organisms from
the Bacteria domain have cells that always possess cell walls with peptidoglycan, Organisms
from the Archaea domain also have cells that always possess cell walls, however these do not
contain peptidoglycan
, What is the lowest taxonomic rank - Answer Species is the lowest taxonomic rank in the
system
Order of taxonomic rank - Answer Domain
Kingdom
Phylum
Class
Order
Family
Genus
Species
Taxonomic groups of a wolf - Answer A wolf is an example of an organism in the Eukarya A
wolf belongs to the following taxonomic groups:
Domain: Eukarya
Kingdom: Animalia
Phylum: Chordata
Class: Mammalia
Order: Carnivora
Family: Canidae
Genus: Canis
Species: lupus
Taxonomic groups of Hibiscus rosa-sinesis - Answer The Hibiscus rosa-sinensis is another
example of of an organism in the eukarya domain It is a colourful flowering plant It belongs to
the following taxonomic groups:
Domain: Eukarya
Kingdom: Plantae
Phylum: Angiospermae
Class: Dicotyledonae
Order: Malvales
Family: Malvaceae
Genus: Hibiscus
Species: rosa-sinensis
Biodiversity and Conservation Latest
Exam and All Correct Answers 2025-
2026 Updated.
What are species - Answer A group of organisms with similar morphological and
physiological features that able to breed together and produce fertile offspring
Morphological species concept - Answer In the past, most scientists described organisms by
their physical features (morphology) as these can be more easily observed, They group together
organisms that share many physical features that distinguish them from other species, This is
the morphological species concept
Ecological species concept - Answer When there is a population of similar organisms living in
the same area at the same time, they can be described as an ecological species. This is the
ecological species concept
Naming of species - Answer The first part of the name is the genus that the species belongs
to; this is a group of very similar organisms. The second part of the name is specific and unique
to a single group of organisms that are identified as a species (and occasionally there may be a
third name). e.g Saccharomyces cerevisiae
Taxonomy - Answer Taxonomy is the practice of biological classification
What is the highest rank in the hierarchical classification system - Answer The highest rank is
the domain
The different cell types - Answer Prokaryotic cells are easily distinguishable in that they lack
a nucleus
Eukaryotic cells have compartmentalised structures, with at least their genetic material
segregated from the rest of the cell in a nucleus
What are three domains - Answer Archaea (prokaryotes)
Bacteria (prokaryotes)
Eukarya (eukaryotes)
Features of archae - Answer Archael cells have no nucleus (and so are prokaryotic). They
were initially classified as bacteria until several unique properties were discovered that
separated them from known bacteria, including:
,Unique lipids being found in the membranes of their cells
No peptidoglycan in their cell walls
Ribosomal structure (particularly that of the small subunit) are more similar to the eukaryotic
ribosome than that of the bacteria
Archaea a similar size range as bacteria (and in many ways metabolism is similar between the
two groups)DNA transcription is more similar to that of eukaryotesExample: Halobacterium
salinarum are a species of the archaea domain that can be found in environments with high salt
concentrations like the Dead Sea
Features of bacteria - Answer These are organisms that have prokaryotic cells which contain
no nucleus. They vary in size over a wide range: the smallest are bigger than the largest known-
viruses and the largest are smaller that the smallest known single-celled eukaryotes. Bacterial
cells divide by binary fission
Example: Staphylococcus pneumoniae is a bacteria species that causes pneumonia
Features of eukarya - Answer Organisms that have eukaryotic cells with nuclei and
membrane-bound organelles are placed in this domain. They vary massively in size from single-
celled organisms several micrometres across to large multicellular organisms many-metres in
size, such as blue whales. Eukaryotic cells divide by mitosis, Eukaryotes can reproduce sexually
or asexually. Example: Canis lupus also known as wolves
Main differences between archae and bacteria - Answer Membrane lipids
Ribosomal RNA
Cell wall composition
How do archae and bacteria differ in their membrane lipids - Answer The membrane lipids
found in the cells of Archaea organisms are completely unique. They are not found in any
bacterial or eukaryotic cells, The membrane lipids of Archaea consist of branched hydrocarbon
chains bonded to glycerol by ether linkages. The membrane lipids of Bacteria consist of
unbranched hydrocarbon chains bonded to glycerol by ester linkages
How do archae and bacteria differ in their ribosomal RNA - Answer Both Archaea and
Bacteria possess 70S ribosomes, The 70S ribosomes in Archaea possess a smaller subunit that is
more similar to the subunit found in Eukaryotic ribosomes than subunits in Bacterial ribosomes.
The base sequences of ribosomal RNA in Archaea show more similarity to the rRNA of Eukarya
than Bacteria, The primary structure of ribosome proteins in Archaea show more similarity to
the ribosome proteins in Eukarya than Bacteria
How do archae and bacteria differ in their cell wall composition - Answer Organisms from
the Bacteria domain have cells that always possess cell walls with peptidoglycan, Organisms
from the Archaea domain also have cells that always possess cell walls, however these do not
contain peptidoglycan
, What is the lowest taxonomic rank - Answer Species is the lowest taxonomic rank in the
system
Order of taxonomic rank - Answer Domain
Kingdom
Phylum
Class
Order
Family
Genus
Species
Taxonomic groups of a wolf - Answer A wolf is an example of an organism in the Eukarya A
wolf belongs to the following taxonomic groups:
Domain: Eukarya
Kingdom: Animalia
Phylum: Chordata
Class: Mammalia
Order: Carnivora
Family: Canidae
Genus: Canis
Species: lupus
Taxonomic groups of Hibiscus rosa-sinesis - Answer The Hibiscus rosa-sinensis is another
example of of an organism in the eukarya domain It is a colourful flowering plant It belongs to
the following taxonomic groups:
Domain: Eukarya
Kingdom: Plantae
Phylum: Angiospermae
Class: Dicotyledonae
Order: Malvales
Family: Malvaceae
Genus: Hibiscus
Species: rosa-sinensis
