lecture 12

Question 1

What group of seed plants is characterized by generally short trunks, pinnate, coriaceous leaves (with
circinate vernation) and dioecy, bearing either male or female cones?

Answer 1

cycadophyta: cyads

Question 2

What are the conifers and what are some families of conifers?

Answer 2

• Dominant in plant communities
  mid-Mesozoic
• Trees or shrubs with simple,
  acicular or subulate leaves
• Leaves may be clustered into
  short shoots (short internodes)
• Extreme: fascicles (e.g., Pinus)
• Non-motile sperm: pollen tubes
• Male gametophyte of conifers delivers the
  sperm cells directly to the egg
• Pollen tube grows into the archegonial
  chamber
• Makes contact with the female gametophyte at
  or near the archegonia
• Sperm cells are then released from the pollen
  tube, make contact with the archegonial egg
  cell, and fertilize the egg nucleus
• Araucariaceae
• Cupressaceae – cypress family
• Podocarpaceae - yew pine
• Taxaceae - yews
• Pinaceae – including cedars,
  pines, spruces, firs, Douglas-fir,
  larches, and hemlock

Question 3

What is the definition of a cone (strobilus)? What are the parts of a female cone? a male cone?

Answer 3

• Male cones with regular male
  sporophylls and sporangia
• Female cones are different from
  those of other plants: compound
  structure
• Axis bearing bracts
• Each bract subtends an
  ovuliferous scale – a modified
  lateral branch system

Question 4

What is the name of the structure in a pine cone that directly bears the ovules/seeds? What was it derived
from? What subtends this structure?

Answer 4

• Female cones are different from
  those of other plants: compound
  structure
• Axis bearing bracts
• Each bract subtends an
  ovuliferous scale – a modified
  lateral branch system

Question 5

What is a pine fascicle?

Answer 5

• Leaves may be clustered into
  short shoots (short internodes)
• Extreme: fascicles (e.g., Pinus)

Question 6

What is the morphology of a conifer pollen grain? What is the possible function of this morphology?

Answer 6

• Male gametophyte of conifers delivers the
  sperm cells directly to the egg
• Pollen tube grows into the archegonial
  chamber
• Makes contact with the female gametophyte at
  or near the archegonia
• Sperm cells are then released from the pollen
  tube, make contact with the archegonial egg
  cell, and fertilize the egg nucleus

Question 7

Name two apomorphies for the Gnetales.

Answer 7

vessels porose
pollen striate

Question 8

Name the three families and four genera of the Gnetales. What do they look like and were do they occur?

Question 9

Name the apomorphies of the flowering plants.

Question 10

What is the definition of a flower?

Question 11

Describe the morphology and adaptive significance of the perianth.

Question 12

What was a major selective pressure that resulted in the evolution of specialized types of flowers?

Question 13

What about the male gametophyte of flowering plants is unique?

Question 14

Describe the structure and function of a mature male gametophyte in the flowering plants.

Question 15

What is endosperm and what is its function?

Question 16

What type of tracheary element do most angiosperms have, and what is its adaptive significance?

Question 17

What are the major groups of basal angiosperms?

Question 18

Name two economically important members of the Lauraceae.

Question 19

What is an economically important member of the Piperaceae?

Question 20

Name and describe the major apomorphies of the monocots