Chapter 29: Plant Diversity 1

Question 1

Diversity Overview

Answer 1

• Land void of plant life for 3 billion years
• ~ 500 mya small plants emerged
• ~385 mya tall plants, forest
• Currently > 290,000 living species

Question 2

Land Plants

Answer 2

• Evolved from green algae (protists)
• Group called the charophytes, closest relative
• Evidence
  
  • 1. Protein rings: cellulose synthesizing
  • 2. Flagellated sperm: structurally similar
  • 3. Phragmoplast: cell plate producing
  • 4. Nuclear & chloroplast genetic similarities

Question 3

Clade

Answer 3

Question 4

Land Plant Advantages

Answer 4

• Advantages to land transition:
  
  • 1. Increased sunlight
  • 2. Increase CO2 availability
  • 3. Soils rich in nutrients
  • 4. Fewer predators

Question 5

Land Challenges

Answer 5

• Challenges to land transition:
  
  • 1. Lack of water
  • 2. Desiccation
  • 3. Lack of structural support
• Diversified once adaptations evolved

Question 6

Derived Traits​

Answer 6

• Appear after split from algal ancestor:
  
  • 1. Alternations of generations
  • 2. Dependent embryos
  • 3. Sporangia & walled spores
  • 4. Multicellular gametangia
  • 5. Apical meristems

Question 7

Alternations of Generations

Answer 7

Question 8

Dependent Embryos

Answer 8

Question 9

Sporangia & Spores

Answer 9

Question 10

Gametangia

Answer 10

Question 11

Apical Meristems

Answer 11

Question 12

Origins of Plants

Answer 12

Question 13

Nonvascular plants

Answer 13

• are collectively called bryophytes
• Phyla include:
  
  • 1. Phylum Hepatophyta (liverworts)
  • 2. Phylum Bryophyta (mosses)
  • 3. Phylum Anthocerophyta (hornworts)

Question 14

Liverworts

Answer 14

Question 15

Moss

Answer 15

Question 16

Hornworts

Answer 16

Question 17

Bryophyte Gametophytes

Answer 17

• are the dominant stage of life cycle
• Body made of
  
  • protonema + gametophores
• Anchored by rhizoids

Question 18

Bryophyte Sporophytes

Answer 18

• Remain attached & depend on gametophyte
• Consists of
  
  • 1. Foot
  • 2. Seta
  • 3. Capsule

Question 19

Moss life cycle

Answer 19

Question 20

Seedless Vascular Plants

Answer 20

• Characteristics
  
  • 1. Sporophyte dominant
  • 2. Vascular tissue
• Two major groups
  
  • 1. Phylum Lycophyta
  • 2. Phylum Monilophyta

Question 21

Sporophyte Dominant

Answer 21

Question 22

Vascular Tissue

Answer 22

• Composed of two types
• 1. Xylem
     * conducts water, minerals
     * strengthened by lignin
• 2. Phloem
     * sugars, organic products

Question 23

Leaves

Answer 23

• Primary photosynthetic organ
• Categorized as
  
  • 1. Microphylls - single vein
  • 2. Megaphylls - branched vascular tissue

Question 24

Sporophylls and Spores

Answer 24

• Sporophylls
  
  • modified leaves
  • bear sporangia
• Spores
  
  • Homosporous – one sporangia, spore
  • Heterosporous – two sporangia, spores

Question 25

Homospory vs Heterospory

Answer 25

Question 26

Phylum Lycophyta

Answer 26

• Collectively called the lycophytes
• Include
  
  • 1. Club mosses*
  • 2. Spike mosses*
  • 3. Quillworts

Question 27

Phylum Monilophyta

Answer 27

• Collectively called the monilophytes
• Include
  
  • 1. Ferns
  • 2. Horsetails - “arthrophytes”
  • 3. Whisk ferns - lack roots