Plant-Animal interactions

Question 1

Plants

Answer 1

• autotrophs: primary producers that energise our planet
• provides food and a habitat
• the basis for radiations in animals is the resources provided by plants

Question 2

As we climb the trophic ladder,

Answer 2

species richness can increase by orders of magnitude

Question 3

Describe a hypothetical oak tree ecosystem

Answer 3

• host several hundred insect herbivore species
• each of these may be utilised by 10-20 species of carnivore or parasite

Question 4

Define predation of plants by animals

Answer 4

plants consumed by animals (without benefit to the plant)

Question 5

Describe predation of animals by plants

Answer 5

• plants attract, trap and digest animal prey
• e.g. Carnivorous plants

Question 6

Describe pollination (plants) by deception (animals)

Answer 6

• plants ‘dupe animals with olfactory/visual deception into pollinating them, with no reward to the animal
• e.g. Bee orchid sapromyiophily

Question 7

Describe symbiosis between plants and animals

Answer 7

• species-specific plant-animal relationships
• pollination, seed dispersal and completion of life cycles, myrmecophytes

Question 8

Describe plants and predation

Answer 8

Plants have evolved numerous defences both chemical and physical

Question 9

Describe sapromyiophily

Answer 9

• pollination by deceit
• composition of volatiles from these flowers and from a rotting carcass is strikingly similar
• pollinators respond in the same way to chemicals from both sources
• remarkably complex mimicry must have evolved to exploit insects as unrewarded pollinators

Question 10

Give a sapromyiophilous species

Answer 10

Helicodiceros muscivorus

Question 11

Describe the VOCs produced by sapromyiophilous species

Answer 11

oligosulphides

Question 12

Describe convergent sapromyiophily

Answer 12

• emerged 4 times
• Piperales, Alismatales, Malphigiales, Gentaniales

Question 13

Define carnivorous plants

Answer 13

1. Attract and capture prey using leaf-derived traps
2. Kill the captured prey
3. Digest the captured
   prey
4. Absorb nutrients from
   the prey
5. Benefit from those
   nutrients

Question 14

Describe the evolution of plant carnivory

Answer 14

• evolved independently in at least 6 major clades
• rare phenomenon
• evolution associated with extreme alterations in morphology
• 600+ carnivorous species
• evolved in response to nutrient economics: typically in water-logged, acidic, mineral-poor conditions;
• remarkable diversity

Question 15

Carnivorous plant lineages

Answer 15

• Alismatales
• Poales
• Caryophyllales (Nepenthes)
• Oxalidales (Cephalotus)
• Ericales (Sarraceniaceae)
• Lamiales
• (Malphigiales)
• (Asterales)

Question 16

Describe the ‘stereotype trap’ forms

Answer 16

• snap
• sticky
• pitfall

Question 17

Describe pitcher plants

Answer 17

• remarkable convergence of traits associated with carnivory
• common solution to the problem of nutrient deficiency evolved across unrelated lineages

Question 18

Describe the Nepenthes pitcher structure

Answer 18

• lid
• peristome
• pitcher

Question 19

Describe the functional surfaces of the Nepenthes pitcher

Answer 19

• peristome
• waxy zone
• viscoelastic fluid

Question 20

Describe other features of a Nepenthes pitcher

Answer 20

• nectar gland
• peristome epidermal cells
• lunate cells
• digestive glands

Question 21

Describe the Order Caryophyllales

Answer 21

• include cacti, carnations and many carnivorous plants
• 33 families (6% of all eudicots)
• flypaper traps such as Sundews (Drosera spp.)
• snap traps (Dionaea)
• also Nepenthaceae
• multiple stereotype trap forms

Question 22

Describe mechano-sensitive traps

Answer 22

• touching triggers hairs
• activates mechano-sensitive ion channels
• mechano-sensors generate bio-electrochemical signal that acts as an action potential; activates motor cells

Question 23

Describe Triphyophyllum

Answer 23

• ‘missing link taxon’
• multiple leaf forms on one plant

Question 24

Describe evolution of the Nepenthes pitcher

Answer 24

• adhesive glands: precursors to
  tentacles
• foliar folding and
  marginal fusion of glandular leaf

Question 25

Describe Nepenthes gracilis

Answer 25

• an ant-specific trap
• novel trapping mechanism
• unique, semi-slippery wax crystal surface on the underside of the horizontal, stiff lid
• secreted more nectar under the lid and less on the peristome; directing prey mainly towards the lid
• utilises impact of rain drops to ‘flick’ insects into the trap (confirmed with simulated rain)

Question 26

Nepenthes albomarginata

Answer 26

a termite-specific trap

Question 27

Nepenthes ampullaria

Answer 27

a detritivore

Question 28

Nepenthes lowii

Answer 28

• ‘tree shrew toilet’
• faecal capture
• flattened large scale ridges
• reduction in small scale ridges

Question 29

Nepenthes rajah

Answer 29

‘tree shrew toilet’

Question 30

Nepenthes hemsleyana

Answer 30

a bat roosting site

Question 31

Describe faecal capture

Answer 31

• substantial changes to nutrient acquisition strategies in carnivorous plants may occur through simple modifications to trap geometry
• at least four species show adaptations for mammalian faecal capture

Question 32

Describe the diversity of Nepenthes pitcher plants

Answer 32

• adaptations to differences in local prey assemblages
• diversity of pitcher geometries in association with different prey
• adaptive radiation
• detritivore; defecation + feeding; defecation + roosting
• may drive such divergence and speciation

Question 33

Describe myrmecophytes

Answer 33

• domatia
• food bodies
• extrafloral nectar
• plants that evolved across about 50 families to produce modified structures that host ant colonies in return for defence and/or nutrients

Question 34

Describe the types of ant-plant interactions

Answer 34

• opportunistic and facultative interactions (protection against herbivores)
• seed dispersal by ants attracted to seed-associated food bodies called elaiosomes
• more intimate obligate interactions (e.g. ant–plant symbioses)