Lecture 19: Non-Vascular and Vascular Seedless Plants (Midterm III)

Question 1

Three phyla of nonvascular plants

Answer 1

1. liverworts, phylum hepatophyta
2. hornworts, phylum anthocerotophyta
3. mosses, phylum bryophyta

• mosses are most closely related to vascular plants

Question 2

In bryophytes, which stage is the dominant stage

Answer 2

gametophyte

Question 3

How often are sporophytes present in the gametophytic stage and how?

Answer 3

only part of the time; embyronically attached to the gametophyte

Question 4

how does a spore become a gametophyte

Answer 4

a spore germinates into a gametophyte composed of a protonema and gamete-producing gametophore

Question 5

____ , not roots anchor ________ to the substrate in the gametophytic stage

Answer 5

rhizoids; gametophytes

Question 6

what constrains the height of gametophytes?

Answer 6

lack of vascular tissue

Question 7

mature gametophytes produce what?

Answer 7

flagellated sperm in antheridia; egg in each archegonium

Question 8

in the gametophytic stage, how do sperm reach and fertilize the egg?

Answer 8

sperm swim through a film of water

Question 9

In the sporophytic stage, bryophyte sporophytes grow out of ?

Answer 9

they grow out of archegonia

Question 10

what are the smallest simplest sporophytes of all extant plant groups?

Answer 10

bryophytes

Question 11

structure of a sporophyte

Answer 11

a foot, seta(stalk), and a sporangium/capsule, which discharges spores through a peristome

Question 12

hornwort and moss sporophytes have what for gas exchange that liverworts do not?

Answer 12

stomata

Question 13

hornwort and moss sporophytes have what for gas exchange that liverworts do not?

Answer 13

stomata

Question 14

seedless vascular plants evolved which two tissues?

Answer 14

xylem and pholoem

Question 15

in seedless vascular plants, what did vascular tissues do? (2)

Answer 15

1. provide structural support
2. allow plants to grow tall

Question 16

seedless vascular plants live in what type of environment and have what?

Answer 16

have flagellated sperm & restricted to moist environments

Question 17

the life cycle of seedless vascular plants involves what dominant generation?

Answer 17

dominant sporophytes w/ well-developed roots & leaves

Question 18

function of xylem (vascular tissue)

Answer 18

• conducts most of the water & minerals & includes dead cells called tracheids
• strengthened by **lignin –> structure **
• allowed increased height

Question 19

function of phloem (vascular tissue)

Answer 19

phloem consists of living cells & distributes sugars, amino acids, and other organic products

Question 20

explain roots and their evolution

Answer 20

1.roots are organs that anchor vascular plants
2. they enable vascular plants to absorb water & nutrients from the soil
3. roots may have evolved from subterranean stems
- bryophytes don’t have roots, they have rhizoids w/no tissues

Question 21

explain leaves and the different types of leaves

Answer 21

1. leaves are organs that **increase the surface area **of vascular plants –> more solar energy used for photosynthesis
2. two types
   a. microphylls - single vein
   b. **megaphylls **- highly branched vascular system

Question 22

What are the two phyla of seedless vascular plants?

Answer 22

1. Lycophyta includes club mosses, spike mosses and quillworts
2. Monilophyte = Pteridophyta includes ferns, horsetails, and whisk ferns and relatives

Question 23

Phylum Lycophyta (seedless vasc. plant)

Answer 23

1. giant lycophytes thrived in moist swamps for millions of years
2. surviving species are small herbaceous plants
3. club mosses and spike mosses have vascular tissues and aren’t true mosses

Question 24

Phylum Monilophyte = Pteridophyta (seedless vasc. plant)

Answer 24

1. ferns are the most diverse seedless vascular plants (12,000 species)
2. most diverse in tropics; also in temperate forests
3. horsetails were diverse during Carboniferous period, now restricted to the genus Equisetum
4. Ferns resemble ancestral vascular plants but are closely related to modern ferns

Question 25

The ancestors of modern lycophytes, horsetails, and ferns grew to great heights during which era which led to ?

Answer 25

Devonian and Carboniferous; forming the first forests

Question 26

What helped with global cooling at the end of the Carboniferous period

Answer 26

increased photosynthesis