10.1 Species and taxonomy

Question 1

What is classification

Answer 1

The organisation of living organisms into groups.

Question 2

What is a species

Answer 2

Similar organisms capable of breeding together to produce living, fertile offspring.

So when they reproduce sexually, any of the genes of its individual can be combined with any other

Question 3

What is the binomial system
Who came up with it

Answer 3

Term coined by Carl Linnaeus.

It is a universal way to name organisms

Organisms are identified by two names:

First name is the generic name -
Denotes the genus to which the organism belongs

Second name is the specific name:
It denotes the species of which the organism belongs

Question 4

What specific details are necessary for when writing the binomial system to name an organism

Answer 4

. The generic first name always has a capital letter at the beginning, but the second name is all in lowercase
. The name is written in italics online, or underlined if written down
. If the specific name is not known, it can be written as sp

Question 5

Why does the classification of species often change

Answer 5

New knowledge is discovered about their evolution, physical features, behaviour, biochemistry

Question 6

Why do individuals of the same species behave similarly

How does it influence survival

Answer 6

The behaviour of members of the same species is more similar than that of members of different species

So individuals can recognise members of the same species by the way they act

If the same species recognise each other, they can reproduce to make fertile offspring to continue the species

Much like how in the same species, the members have similar genes so resemble each other physically and biochemically

Question 7

How is courtship behaviour necessary for the survival of a species

5 reasons

Answer 7

• They can recognise individuals of the same species to ensure that mating only occurs within a species to produce fertile offspring
• Identify a mate that is capable of breeding because both partners need to be sexually mature
• Form a pair bond which will lead to successful mating and raising of offspring
• Synchronise mating so it occurs when there is maximum probability of the sperm and egg meeting
• Become able to breed by bringing a member of the opposite sex into physiological state that allows breeding to occur

Question 8

When are females of a species able to reproduce

How does courtship by males help the odds of this happening

Answer 8

In the period of time they produce eggs (it is very short)

Males can test if females are in this stage, and they can see her behavioural response to it to see if courtship will continue

Eg signals and a chain of actions will be the same in one species

If she is not receptive there will be a different pattern of behaviour so the males will go elsewhere

Question 9

What is taxonomy
What are the two types of biological classification

Answer 9

The theory and practice behind of biological classification

There are two main types of biological classification:
Artificial and phylogenetic

Question 10

What is artificial classification

Answer 10

It divides organisms according to differences that are useful at the time
Eg colour, size, number of legs, leaf shape

These are analogous characteristics where they have the same function but different evolutionary origins
Eg wings of butterflies and birds are both used for flight, but they originated in different ways

Question 11

What is phylogenetic classification

Answer 11

.Based on the evolutionary relationships between organisms and their ancestors

. It classifies species into groups using shared features derived from their ancestors

. Arranges the groups into a hierarchy, in which the groups are contained in larger composite groups with no overlap

Question 12

What is a hierarchy

Answer 12

Smaller groups arranged within bigger groups
No overlap between groups

Question 13

What is taxonomy in phylogenetic classification

Answer 13

Each group in a phylogenetic classification is called a taxon

Taxonomy is the study of these groups and their positions in hierarchal order

These are based on the evolutionary descent of its members .

Question 14

What are the 3 types of domain

Answer 14

. Bacteria, archaea and eukarya

Question 15

What is the bacteria domain

Give some characteristics

Answer 15

. Group of single celled prokaryotes

• No membrane bound organelles
• Circular single strand of DNA made of nucleic acids but no histones
• Unicellular
• Small 70s ribosomes
• Cell walls made of murein (not cellulose or chitin)

Question 16

What is the Archaea domain
Give some characteristics

Answer 16

. Group of single celled prokaryotes that were originally classified as bacteria but are actually different because…

• No murein in cell walls
• Genes and protein synthesis are more similar to eukaryotes
• Their membranes have fatty acid chains attached to glycerol by ester bonds
• Have more complex form of RNA polymerase

Question 17

What is the Eukarya domain
Give some characteristics

Answer 17

Group of organisms made up of one or more eukaryotic cells
Their features are:
- Cells possess membrane bound organelles eg mitochondria or chloroplasts
- They have membranes made of fatty acids and glycerol joined by ester bonds
- Not all possess cell wall, but where they do it is made of cellulose
- Ribosomes are large 80s ones

Question 18

What are the 4 kingdoms in Eukarya

Answer 18

. Protoctista
. Fungi
. Plantae
. Animalia

Question 19

What is the order of classification
In Eukarya

Answer 19

Kingdom
Phylum
Class
Order
Family
Genus
Species

Remember it by
King Philip came over for good soup

Question 20

What does the phylum depend on

Answer 20

Within each kingdom, there are different body plans

A group of organisms with developmental similarity

Question 21

What does class depend on

Answer 21

The phylum, so the body plan eg exoskeleton or jointed legs

Question 22

What is phylogeny

What term is it derived from

In what format is it represented

Answer 22

Hierarchical order of taxonomic ranks is based on evolutionary line of descent of the group members

This evolutionary relationship between organisms is known as phylogeny

Term derived from phylum, and phylogeny reflects the evolutionary branch that led up to it

Phylogenetic relationships of different species is usually represented by a tree diagram called phylogenetic tree
Oldest species at base of tree whilst most recent ones are at the ends of branches