Lecture 1: What is Biodiversity?

Question 1

Biodiversity is

Answer 1

the variety of life, in all its manifestations. IT encompasses all forms, levels and combinations of natural variation.

Question 2

3 different categories of biodiversity

Answer 2

Ecological, Genetic and organismal. All have populations in common.

Question 3

Ecological diversity

Answer 3

Biomes
bioregions
Landscapes
Ecosystems
Habitats
Niches
Populations

Question 4

Genetic diversity

Answer 4

Populations
Individuals
Chromosomes
Genes
Nucleotides

Question 5

Organismal diversity

Answer 5

Domains of kingdoms 
Phyla
Families
Genera
species
subspecies
populations
individuals

Question 6

Example of biodiversity plant kingdom. Why they so fascinating?

Answer 6

• the major primary producer
• represent an est 90% of all biomass
• single most important influence on Earth’s environment and global change
• food, drugs,materials and fuel.
• aesthetically pleasing
• jobs!

Question 7

Cambrian life in the ocean and on the land before the advent of land plants:

Answer 7

Only one carbon cycle as only life in the oceans.

Question 8

Origin of land plants and now:

Answer 8

2 carbon cycles as life on land and in ocean.

Question 9

Life on earth before the origin of land plants:

Answer 9

• Pond scum-free living organisms in bodies of freshwater (rivers, lakes etc.)
• Microbial mats on damp surfaces periodically inundated with water (lake margins, estuary mudflats etc.)
• Biological soil crusts on rudimentary rocks
• Within or beneath rocks as endoliths

Question 10

whats an endoliths

Answer 10

An endolith is an organism that lives inside rock, coral, animal shells, or in the pores between mineral grains of a rock.

Question 11

Life’s challenges from salt water to land

Answer 11

salt water -> river water -> land

Question 12

Physiological problems for when migrating from an aquatic to subaerial habitat:

Answer 12

• water balance
• availability of essential nutrients and gases
• support
• UV protection
• Necessary alterations in reproductive strategy

Question 13

Water balance for when migrating form aquatic -> subaerial habitat:

Answer 13

Plants are no longer bathed in water. Therefore they utilize rhizoids/roots [collection], xylem [transport], cuticle and stomata [desiccation avoidance])

Question 14

essential nutrients and gases for when migrating form aquatic -> subaerial habitat:

Answer 14

(Plants are no longer bathed in water containing dissolved essential nutrients and gases. Therefore, they have to collect them from the soil and atmosphere using roots and stomata)

Question 15

Support for when migrating form aquatic -> subaerial habitat:

Answer 15

Plants no longer supported in an aquatic medium. Therefore, they use lignified conducting tissues to provide support)

Question 16

UV protection for when migrating form aquatic -> subaerial habitat:

Answer 16

(Plants no longer protected from UV by water absorption. Therefore, they use cuticle)

Question 17

1. Necessary alterations in reproductive strategy for when migrating form aquatic -> subaerial habitat

Answer 17

(Plants can no longer release their gametes directly into an aquatic medium in which it is easy to move and UV is filtered. Therefore, they must protect them by enclosure in a sporopollenin wall (spore wall) with dispersal by new vectors-wind/animals)

Question 18

Land plants are divided into two main groups:

Answer 18

• Non vascular plants (Bryophytes)

- vascular plants (tracheophytes)

Question 19

Non-vascular plants (Bryophytes)

Answer 19

o Conducting tissues are not lignified: hydroids + leptoids.

o Gametophyte dominant with sporophyte subsidiary.

Question 20

Vascular plants (Tracheophytes)

Answer 20

o Sporophyte dominant with gametophyte subsidiary.
o Conducting tissues lignified: xylem (conducts water: tracheids or vessels) + Phloem (conducts food: sieve tubes or sieve cells)

Question 21

example of Bryophytes (non-vascular plants)

Answer 21

• liverworts
• mosses
• hornworts

Question 22

examples of Vascular plants: Free-sporing:

Answer 22

• Lycopsids
• Sphenopsids
• Ferns

Question 23

example of Vascular plants: Seed plants (Gymnosperms):

Answer 23

• Ginkgos
• Cycads
• conifers
• Gnetales

Question 24

Angiosperms definition:

Answer 24

seed & more importantly flowering plants

Question 25

Gymnosperms:

Answer 25

vascular seed plants

Question 26

Evidence utilised in the study of the origin of land plants

Answer 26

Extant plants:
Analysis of living plants provides information on-
- Evolutionary relationships of living plant groups
- Physioogical changes required to make the trainsition from an aqueous to a subaerial existence.
Fossil Evidence:
Fossil evidence provides us with the only direct evidence as to the nature of the plants that lived at a particular time (inc. groups that became extinct). It also provides evidence as to the timing of evolutionary events.