Biology WJEC AS 2.1

Flashcards created to review key concepts related to biological classification and taxonomy based on lecture notes.

What is the three domain classification system?

A classification system that categorizes life into Bacteria, Archaea, and Eukarya based on evolutionary relationships.

What are extremophiles?

Microorganisms that thrive in extreme environmental conditions such as temperature, pH, salinity, and pressure.

What is the biological definition of a species?

Organisms that are able to breed together and produce fertile offspring.

What does the term 'phylogenetic classification system' refer to?

A system that arranges species into groups (taxa) based on their evolutionary relationships.

What is the binomial nomenclature?

A formal system of naming species, consisting of the genus name and the species name, often in Latin.

What are the five kingdoms of life?

Animalia, Plantae, Fungi, Protoctista, and Prokaryotae.

What is the role of ribosomal RNA in classification?

It helps establish the close evolutionary relationships between different domains.

What does the genus represent in the binomial naming system?

The genus is the first part of the binomial name, written with a capital letter.

What is a key point about the classification hierarchy?

It includes categories such as Kingdom, Phylum, Class, Order, Family, Genus, and Species.

What is a class ?

a group of organisms that all possess the same general traits

What is the phylum ?

major subdivision of the kingdom and contains all the groups of organisms that have the same body plan e.g those who have a backbone are chordata

Who developed the bionomial naming system ?

Carl linnaeus

What are the 8 classifications ?

Domain , kingdom , phylum , class , order , family , genus , species

Advantages of using the bionmial naming system?

1. a universal name which will be used by every scientist in every country

2. translation of languages and dialects may guve different names

3. The same common name may be used fro different soecies in other parts of the world

What do the branch points represent in a phylogenetic tree ?

common ancestors

What are taxa ?

levels of cklassification

Why do we need to classify living organisms ?

1. to infer revolutionary relationships

2. to predict other characteristics

3. to make communication easier

4. Easier to track the health of an ecosystem

What are Eubacteria ?

Familiar bacteria such as E.coli and Samonella . Thye are prokaryotes

What are Archaea ?

They are often bacteria and have unusual metabolism .

They live in marginal habitats .

They are prokaryotes

What are Eukaryota ?

This domain includes : plantae , animalia , fungi and protoctista . They are all eukaryotic

Characteristic of prokaryotae

1. Microscpoic

2. SIngle celled

3. no membrane bound organelles

4. cell wall made out of meurin

Characteristic of protoctista

1. eukaryotic

2. single celled

3. no tissue differentitation

Characteristic of fungi

1. Heterotrophic eukaryotes

2. cell wall made of chitin

3. reproduce by spores

Characteristic of planta

1. multicellullar eukaryotes

2. photosynthetic

3. cellulose cell walls

Characteristic of animalia

1. multicellular eukaryotes

2. heterotrophic

3. no cell wall

4. has nervous coordination

What are the kingdoms based on ?

Based on morphological similarities not dna analysis

How to determine relatedness from DNA Base sequence ?

more closely related species shwo more similarity in their dna base sequence

How to determine relatedness from DNA hybridisation ?

The more DNA base sequences hybridise , the more closely related the species are

How to carry out DNA hybridisation ?

1. DNA is extracted, seperated and cut into fragments

2. Fragments are mixed

3. Where they have complementary bases , they hybridise

How to determine relatedness from amino acid sequence ?

The more amino acid bases thye have in common , the more closely related they are

How to determine relatedness from immunology?

The closer the veolutionary relationship , the more precipitate will form (the more antigen and antibody will react)

How to test for relatedness using immunology ?

mix the antigens of one species with specific antigens from another . The antigens and antibodies that are complementary will form a precipitate .

What are homologous structures

Have the same structure but different function .E.g pentdactyl limb

What are analogous structures

Have different strcuture but a similar function

What is biodiversity ?

A measure of different kinds of organisms in a region or other defined area

How does biodiversity change ?

Through extinction

What is extinction ?

Loss of species

What can cause extinction ?

1. a change in climate or habitat

2. increased competition

3. new predators

4. new diseases

What is speies richness ?

the number of species in a region or a specified area

What is species evenness ?

the degree of equitability in the distribution of individuals among a group of species

What is a bottle neck ?

sudden decrease in biodiversity

What is adaptive radiation ?

seevral new species evolving from a common ancestor due to natural selection

What are the 6 steps of natural selection ?

1. mutation

2. variation

3. competition

4. survive

5. reproduce pass on alleles

hwo to describe the “mutation” ?

Chnages in DNA to form a new allele / gene

hwo to describe the “variation ” ?

this leads to variation in species

hwo to describe the “competition”?

some individuals are better suited to the environment . they outcompete other individuals fro the resources needed to survive

hwo to describe the “survive ” ?

the individuals best suited to the environment survive

hwo to describe the “reproduce” ?

Those best suited survive and reproduce

hwo to describe the “pass on allele” ?

The offspring of the survivors inherit the advantagous allele so that they are also best suited to the environment

The three types of adaptation

anatomical , physiological and behavioural

What are anatomical adaptations ?

a structural adaptation

What are physiological adaptations ?

a change of the normal function

What are behavioural adaptations ?

a specific behaviour

What is conservation ?

actively planning to protect a species or habitat

How do CITES conserve biodiversity ?

Ban the sale of endangered species and their parts and products

How do SSSI conserve biodiversity ?

protect habitats from overdevelopment

How do government agencies and WWFN conserve biodiversity ?

Educate , lobby governments , raise awareeness and fund conservation projects . Monitor changes in biodiversity and alert us to changes in the organisms’ risk status

How do captive breeding programs conserve biodiversity ?

Breed endangered species in captivity ,esnuring limited human contact .Then reintroduce the organisms into the wild and monitor their numbers

how do seed banks conserve biodiversity ?

carry out research into plant species and their genetic diversity . Collect and preserve seeds of all species .

How does government legislation conserve biodiversity ?

pass legislation to protect habitats and species at risk