Year 12 Biology - UNIT 3 TOPIC 1. Classification Processes

Question 1

LInnaean System

Answer 1

Classification system created by ‘Carl Linnaeus’ in the 1750s. Focuses on the similarity of physical features into taxons or hierarchical levels (domain, kingdom, phylum, class, order, family, genus, species)

Question 2

Kingdom

Answer 2

The second highest taxon in Linnaean classification; includes Animalia, Plantae, Protista, Fungi, Archaea, Bacteria

Question 3

Phylum

Answer 3

The third highest taxon in Linnean classification

Question 4

Prokaryote

Answer 4

‘Prokaryotes’ do not contain membrane-bound organelles, the nucleus is also absent. They are unicellular (Bacteria & Archaea). They are typically smaller in size in comparison to eukaryotes and they multiply through binary fission. Because Prokaryotic DNA interacts with cytoplasm, transcription and translation occur simultaneously.

Question 5

Classification Systems

Answer 5

All are hierarchical and based on different levels of similarity.
1. Linnaean system - similarity of physical features
2. Methods of reproduction - asexual or sexual (eutherian, marsupial, monotreme)
3. r/K selection - mathematical classification based on the number of offspring and parental care
4. Molecular phylogeny/cladistics - similarity of molecular sequences

Question 6

Classification Systems

Answer 6

All are hierarchical and based on different levels of similarity.
1. Linnaean system - similarity of physical features
2. Methods of reproduction - asexual or sexual (eutherian, marsupial, monotreme)
3. r/K selection - mathematical classification based on the number of offspring and parental care
4. Molecular phylogeny/cladistics - similarity of molecular sequences

Question 7

Domain

Answer 7

The highest ranking taxon in Linnaean classification; includes Eukarya, Archaea, Bacteria

Question 8

Eukaryote

Answer 8

‘Eukaryotes’ are cells that have a nucleus (membrane-bound) and other Membrane-bound organelles (aside from nucleus). These cells can either be unicellular (Fungi & Protis) or multicellular (Plant & Animal cells). Eukaryotes are typically larger in size in comparison to prokaryotes. In these cells, transcription occurs within the cell and translation within the cytoplasm. They multiply through mitosis and meiosis.

Question 9

Clade

Answer 9

A group of organisms that consist of a common ancestor and all its lineal descendants

Question 10

r/K Selection

Answer 10

A form of mathematical classification based on the number of offspring a species produces and the level of parental involvement required to care for them

Question 11

Division

Answer 11

The third highest taxon in LInnaean classification (eg- Tracheophyta/ vascular plants)

Question 12

Order

Answer 12

The fifth highest taxon in Linnaen classification (eg-Carnivora)

Question 13

Hierarchy

Answer 13

A system categorised by the specific arrangement of information into layers

Question 14

Cladistics (molecular phylogeny)

Answer 14

A taxonomic technique that arranges organisms by clade or descendants of particular ancestor organisms.

Question 15

Class

Answer 15

The fourth highest taxon in Linnean classification (eg- Mammalia)

Question 16

Taxonomy

Answer 16

A system of classification, particularly biological; the study of systems of classificarion

Question 17

Taxon

Answer 17

A level of hierarchical classification system (Eg- Kingdon, Family, Species)

Question 18

Methods of reproduction

Answer 18

Type of classification - asexual or sexual. Class Mammalia is split into three main based on where offspring develop
1. Eutherian - Offspring develop completely in the mother with an attached placenta and has a live birth
2. Marsupial - fetus brighter at a very early developmental stage and complete development in the pouch
3. Monotreme - offspring develop in eggs

Question 19

Family

Answer 19

The sixth highest taxon in Linnaean classification (Eg- Felidae)

Question 20

Species

Answer 20

The lowest taxon in Linnaean classification; it is always italicised and combined with genus (eg- Felis catus)

Question 21

Bifurcaction

Answer 21

The division of something into two branches or parts

Question 22

Binomial Nomenclature

Answer 22

A naming system in which each individual is given a two-part name, such as genus and species or first name and surname

Question 23

Genus

Answer 23

The seventh highest taxon in Linnaean classification; it is always italicised (Eg- Felis)

Question 24

Common Ancestor

Answer 24

A species of organism whose offspring diverges over time

Question 25

Assumptions of Cladistics

Answer 25

Assumptions include:
- common ancestry
- bifurcation
- physical change

Question 26

Plesiomorphic

Answer 26

Having characteristics or traits that are common among their evolutionary relatives, but are not unique to their clade (Eg- members of class Reptilia usually have legs as do many organisms no in class Reptilia)

Question 27

Node

Answer 27

A point in a diagram where lines branch or intersect

Question 28

Molecular Homology

Answer 28

The identification of shared biomolecular elements - generally genes; used to test the relationships between organisms, which can demonstrate common ancestory

Question 29

Cladograms

Answer 29

Phylogenic tree diagrams that show the most probable sequence of divergence in clades; grouped according to their most likely evolutionary relationships

Question 30

Apomorphic

Answer 30

Having characteristics or traits unique to a particular group of organisms that are different from their evolutionary relatives (Eg- snakes, in class Reptilia, have no legs)

Question 31

Conserved Sequence

Answer 31

DNA or protein that is preserved across species due to optimal function.

Question 32

Question: Why are multiple definitions of species needed?

Answer 32

1. Biological species concept - the capacity to interbreed by two individuals; speciation occurs when breeding cannot occur naturally.
2. Hybrid organisms exists - interbreeding of teo species (Eg- donkey + zebra +zonkey); difficult to classify because they are bred from two species.
3. Morphological species concept - based on physical characteristics - Fossilis: impossible. with extinct organisms; we don’t know if they could interbreed or if physical differences mean a new species or just a variation in species
4. Ohylogenic species concept - based on common ancestor; relies on cladistics which is limited to scientists understanding of the genetics of organisms.

Question 33

Question: Explain how molecular sequences are used to infer species evolutionary relatedness

Answer 33

• protein conservation
• molecular sequencing
• histones
• dating divergence
• mutations

Question 34

Questions: Explain how ecosystems are composed of varied habitats (microhabitat to ecoregion)

Answer 34

• rainforest canopies
• vertical stratification

Question 35

Describe the process of stratified sampling in terms of:
- purpose
- site selections
- surveying technique
- bias
- methods of data presentation and analysis

Answer 35

1. Purpose - estimating population, density, distribution, environmental gradients and profiles, zonation, stratification
2. Site selections
3. choice of ecological surveying technique - quadrant, transects
4. minimising bias - size and number of samples, random-number generators, counting criteria, calibrating equipment and noting associated precision
5. Methods of data presentation and analysis

Question 36

Question: Explain an example of an interspecific hybrid that does not produce fertile offspring

Answer 36

Mules, bananas, grolars

Question 37

Question: Explain the classification of organisms according to the following species interactions: predation, competition, symbiosis and disease

Answer 37

• Predation: 1 species kills and teats the other
• Competition: 2 or more individuals (whether the same species or not) compete for the same resources in the same area
• Symbiosis: a relationship between individuals or 2 or more species in which at least one organism benefits from the interaction: no death, just sickness; parasitism
• Disease: where a pathogen damages or kills a host

Question 38

1/Question: Explain how the process of classifying ecosystems in an important step towards effective ecosystem management (consider old-growth forests, productive soils and coral reefs)

Answer 38

• allows decision-making about ecosystem, Can understand diversity
• consider different stakeholders
• management techniques
  help reduce human impacts leading to long-term resilience