Biology paper 2

What is the biggest taxonomic group?

Kingdom

What are the seven groups?

Kingdom,phylum,class,order,family, genus and species

Why do scientists classify organisms?

To identify species, to predict characteristics and to find evolutionary links

What is the most recent level of hierarchy added to the taxonomic groups?

Domain

What are the three domains?

Archaea, bacteria and eukarya

What are the species of humans?

Homo sapiens

What is the definition of a species?

A group able to reproduce to produce fertile offspring

What is an example of an animal who is in fertile and therefore not a species ?

A mule bred by a donkey and horse

Why are some animals in fertile?

Their cells contain an odd number of chromosomes meaning that meiosis cannot take place

What language is binomial nomenclature?

Latin

How does the binominal nomenclature work?

All species are given a name consisting of two parts where the first word indicates the organisms genus (generic name) and the second word indicates the organisms species (specific name)

When naming an organism with its scientific name what should it be written in?

Italics or underlined

Is the first letter of the genus name upper or lower case?

Lower

What species does the "Capra aegagrus" belong to?

Aegagrus

Which kingdom contains single-celled organisms without membrane bound organelles?

Prokaryotae

What are the five kingdoms?

Prokaryotae, protoctista (the prokaryotes) and fungi, plantae and animalia (the eukaryotes)

Which kingdom contains single-celled organisms with membrane-bound organelles?

Protoctista

What do protoctista sometimes contain?

Chloroplasts

How are nutrients absorbed in prokaryotae ?

Through cell walls or produced internally by photosynthesis

How are nutrients acquired in protoctista ?

By photosynthesis (autotrophic feeders), ingestion of other organisms (heterotrophic feeders) or both as some as parasitic

Which kingdom contains both unicellular and multicellular organisms?

Fungi

Which kingdom contains autotrophic, multicellular organisms?

Plantae

What is an example of fungi?

Mushrooms, moulds and yeast

What is the cell wall of fungi composed of?

Chitin

Do fungi have chloroplasts or chlorophyll?

No

What is the body of fungi made of?

Threads or hyphae

How are nutrients acquired in fungi?

By absorption from decaying material (saprophytic feeders) and some are parasitic

How do fungi store food?

Glycogen

Which kingdom contains the most organisms?

Animalia

Which kingdom is the second largest?

Plantae

What type of feeders are the plantae kingdom?

Autotrophic feeders as they make their own food

How do plantae store food?

As starch

What is the cell wall of plants composed of?

cellulose

Do animals have cell walls?

No

How do Animalia kingdom move?

Cilia, flagella or contractile proteins

How are nutrients acquired by animalia kingdom?

Ingestion (heterotrophic feeders)

Which kingdom contains multicellular heterotrophic organisms?

Animalia

Which kingdom is unicellular and have no nucleus or other membrane bound organelles?

Prokaryotae

How many kingdoms are in the Eurkaya domain?

4

Which kingdom is split in half by the bacteria and archaea domain?

Prokaryotae

What are the three domains?

Archaea, Bacteria, Eukarya

How are the organisms in the three domain system different to eachother?

Have a unique form of rRNA and different ribosomes

What ribosomes do eukarya have?

80s

What RNA does Eukarya have?

RNA polymerase containing 12 proteins

What ribosomes do Archaea have?

70s

What RNA does Archaea have?

RNA Polymerase between 8-10 proteins

How many ribosomes do bacteria have?

70s

How many proteins does RNA Polymerase in bacteria contain?

5

Which kingdom does an amoeba belong to?

Protoctista

How does the prokaryotae kingdom become divided?

Into archaebacteria and eubacteria

What are the six kingdoms in the six kingdoms classification system?

Archaebacteria, eubacteria, protoctista, fungi, plantae and animalia

Although both archaebacteria and eubacteria are single celled why is eubacteria classified into its own kingdom?

It's chemical makeup is different as they contain peptidoglycan (a polymer of sugars and amino acids) and archaebacteria does not

What are the three commonly used classification systems?

The three domain, the six kingdom and the traditional five kingdom system

Which bacterial domain contains most species?

Eubacteria

Where can archaebacteria live?

extreme environments

Where can eubacteria live?

All environments

What is phylogeny?

The study of evolutionary relationships among organisms.

How is phylogeny represented?

In a phylogenetic tree

In a phylogenetic tree where are the earliest species found?

At the base of the tree

In a phylogenetic tree where are the most recent species found?

At the tips of branches

Where has the evidence for phylogenetic trees come from?

Fossils

What do the nodes of the tree represent?

Common ancestors of descendants

What are two descendants split from the same node called?

Sister groups

If the branches are close what does this mean?

The closer the evolutionary relationship

What is one advantage of phylogeny?

Produces a continuous tree whereas classification requires discrete taxonomical groups

What is the issue with classification that is resolved by phylogeny?

Linnaean classification implies different groups within same rank are equivalent

What was Darwin's Theory of Evolution?

Natural selection

What is the 3 evidence for evolution?

Paleontology, comparative anatomy, and comparative biochemistry

How are fossils formed?

When animal and plants remains are preserved in rocks

What is paleontology?

Study of fossils

What is the fossil record?

the evolution of living organisms through geological time shown by fossils.

Why is the fossil record incomplete?

Some organisms decompose quickly and don't fossilise, conditions needed for organisms to become fossils are not always present, many have been destroyed by earth's movement or still lie undiscovered

What is comparative anatomy?

The study of similarities and differences in the anatomy of different species.

What is a homologous structure?

Structure that appears superficially different in different organisms but have same structure

Give an example of comparative anatomy

Pentadactyl limb of vertebrates

What does the presence of homologous structures provide evidence for?

Divergent evolution

What is divergent evolution?

Describes how, from a common ancestor, different species have evolved each with a set of adaptive features

How does divergent evolution occur?

When closely related species diversify to adapt to new habitats as a result of migration or loss of habitat

What is comparative biochemistry?

Study of similarities and differences in the proteins and other molecules that control life processes

What are two of the most common molecules studied in comparative biochemistry?

Cytochrome c, a protein involved in respiration and ribosomal RNA

How can scientists estimate the point at which two species last shared a common ancestor?

The number of differences that exist is plotted against the rate the molecule undergoes neutral base pair substitutions

What does the hypothesis of neutral evolution state?

That most of the variability occurs outside of molecules functional regions so it's function is not affected

What is variation?

The differences in characteristics between organisms

What is variation between different species?

Interspecific

What is variation between organisms within the same species?

Intraspecific

What are the two factors that cause variation?

Organisms genetic material \= genetic variation and the environment in which the organism lives

How is genetic variation caused within a population?

Alleles, mutations, meiosis, sexual reproduction and chance

Is there greater variation in organisms which produce asexually or sexually?

Sexually

What does asexual production result in?

Production of clones (genetically identical to parents) therefore genetic variation can only occur through mutation

Give an example of an environmental cause of variation

Scars on your body

In most cases genetic variation is caused by a combination of...?

Environmental and genetic such as height or skin colour

What is discontinuous variation?

A characteristic that can only result in certain values

What is variation?

The differences in characteristics between organisms

How is discontinuous variation represented?

Using a bar chart and sometimes pie chart

What is continuous variation?

A characteristic that can take any value within a range

What is variation between different species?

Interspecific

What is a continuum in continuous variation?

Where there is a graduation in values from one extreme to the other of a characteristic

How is continuous variation represented?

In a frequency table and plotted on a histogram

When continuous variation data is plotted into a graph what curve is formed?

A normal distribution curve (bell-shaped)

What are the characteristics of a normal distribution curve?

\-Mean,mode,median are the same.

\-bell shape which is symmetrical about the mean

\-50% values are less than mean and 50% greater than mean

\-most values lie close to mean value (extremes are low)