Module 3 - Biodiversity

Question 1

Biodiversity is often described on three levels:

Answer 1

1. ecosystem diversity describes variety of habitats present
2. species diversity is a measure of number of species and the number of individuals of each species present
3. genetic diversity refers to the total amount of genetic variability present

Question 2

Discipline of systematics

Answer 2

scientific study of the kinds and diversity of organisms and the relationships among them

Question 3

What are the three sub-disciples of systematics:

Answer 3

1. taxonomy
2. nomenclature
3. phylogenetics

Question 4

Taxonomy

Answer 4

theory and practice of classifying organisms into taxa within a hierarchy (classification of life)

Question 5

Nomenclature

Answer 5

scientific names are produced for taxa to provide common ground where specific taxa can be communicated (naming organisms)

Question 6

Phylogenetics

Answer 6

study of the evolutionary history of relationships of organisms

Question 7

How was scala naturae (scale of nature) for taxonomy first order by?

Answer 7

based on complexity of structure and ability to move (based on modes of transportation)

Question 8

What is the modern classification list?

Answer 8

(ranked from broad to more specific)
- domain
- kingdom
- phylum
- class
- order
- family
- genus
- species

Question 9

What are the 3 traits of class mammalia? (all mammals have)

Answer 9

• hair (insulation, aid in sensory touch)
• mammary glands (milk)
• 3 ear bones (transmissions of vibrations from eardrum to inner ear)

Question 10

what are the 3 domains:

Answer 10

• Bacteria (prokarya)
• Archea (prokarya)
• Eukarya

Question 11

Characteristics of Bacteria (Pro)

Answer 11

• circular chromsome
• peptidoglycans in cell wall
• membrane lipids ester-linked (bonds not branched)

Question 12

Peptidoglycans

Answer 12

composed of carbohydrates cross-linked by peptides (2 or more amino acids linked in chain)

Question 13

Characteristics of Archea (Pro)

Answer 13

• has circular chromosomes
• no peptidoglycans in cell wall
• membrane lipids are ether-linked (stronger bond, more resistant to extreme temperature)

Question 14

Rules for binomial nomenclature system:

Answer 14

• each type of organism has only one name
• no two kinds of organisms bear the same name

Question 15

Change in scientific names

Answer 15

Scientific names may change but the species authority and genus authority do not (original person and year
- bracket = name change

Question 16

What are the 3 types of extant mammals?

Answer 16

• Placentals (eutheria): have a placenta
• Marsupials (metatheria): Live birth
• Monotremes (Prototheria): lay eggs, no live birth

Question 17

What does the Law of Priority state?

Answer 17

if a genus or species has been accidentally given two names, only the earlier one is valid
- later name becomes a “junior synonym”

Question 18

Holotype

Answer 18

single specimen designated as the name-bearing type of a species when it was established (by original author)
- representative of whole group
- holotype for each species

Question 19

Allotype vs Paratype

Answer 19

Allotype: specimen of the opposite sex to the holotype (second most important specimen)
Paratype: specimen of the type series other than the holotype (offspring of holotype)

Question 20

Where are type specimens kept?

Answer 20

they must be preserved permanently and may not be living plants or cultures
- people need to compare them

Question 21

What are species?

Answer 21

organisms classified based on their appearance (morphological species concept)
- Morphology: outward appearance and the form and structure of the internal parts
- identify species by morphological features

Question 22

What can you not apply the biological species concept to?

Answer 22

1. fossils
2. asexually reproducing individuals

Question 23

Biological species concept

Answer 23

interbreeding natural populations whose individuals are reproductively isolated
- for them to be the same species they have to produce viable offspring (not hybrids)
- based on natural population not human interference

Question 24

Ecological species concept

Answer 24

species defined in terms of their ecological niches, focusing on unique adaptations (what does it need to survive?)

Question 25

Interbreeding

Answer 25

sharing a common gene pool and must produce viable offspring (not hybrid)

Question 26

What types of barriers prevent reproduction between two species?

Answer 26

1. prezygotic reproductive barriers - prevent mating of fertilization (if they do mate, no fertilization) 2. postzygotic reproductive barriers - prevent development of fertile adults

Question 27

Prezygotic reproductive barriers

Answer 27

1. Habitat isolation 2. Temporal isolation 3. behavioral isolation 4. mechanical isolation 5. gamete isolation

Question 28

Habitat isolation

Answer 28

species may occupy different habitats, so they don't come in contact with each other (separate by type of environment) Ex. garter snakes live in moist meadows and open grassy patches and ribbon snakes live in shallow water

Question 29

Temporal isolation

Answer 29

species have different mating or flowering season or times of day, become sexually mature at different times of year Ex. field crickets co exist but have different breeding seasons

Question 30

Behavioural isolation

Answer 30

little or no sexual attraction between males and females of different species due to difference in behaviour Ex. bird species use different songs to attract mates

Question 31

Sympatric

Answer 31

Species co existing with one another

Question 32

Conspecifics vs No conspecifics

Answer 32

conspecifics: everything of the same species no conspecifics: everything that is not of the same species

Question 33

Mechanical isolation

Answer 33

structural difference in genitalia or flowers prevent copulation/pollen transfer between two species (they can try but nothing will happen) - adapted to specific pollinators Ex. certain flowers are visited by bumblebees others by birds

Question 34

Gamete isolation

Answer 34

male and female gametes die before uniting or fail to unite - released but can't penetrate - by random chance if they get fertilized

Question 35

Postzygotic reproductive barriers

Answer 35

1. Hybrid inviability 2. Hybrid sterility 3. Hybrid breakdown

Question 36

Hybrid inviability

Answer 36

hybrid zygotes fail to develop or to reach sexual maturity - produce offspring but can't survive - not compatible for environment

Question 37

Hybrid sterility

Answer 37

hybrids fail to produce functional gametes (sterile) - has no function or reproductive system

Question 38

Hybrid breakdown

Answer 38

offspring of hybrids are weak or infertile - first generation will survive but second generation will be weak