Lab Quiz 3 (lab 7: free-sporing plants)

Question 1

What specialized structures does a liverwort have for gamete production?

Answer 1

gametangia: antheridiaphores and archegoniophores

Question 2

(looking at beached thallus liverworts on display)

What are the openings in the epidermal layer and what is their function?

Answer 2

The openings are pores, and their function is gas exchange

Question 3

(looking at gamma cups of liverworts)
Are the gemmae haploid or diploid?
Are gemmae the result of vegetative (clonal) or sexual reproduction?

Answer 3

Gemmae are haploid,

and are the result of vegetative reproduction

Question 4

(moss life cycle)

What are the similarities with the liverwort life cycle?

Answer 4

Gametophyte dominant

Question 5

(sporophytes of living moss)

What is the name of the structure that houses the spores?

Answer 5

The capsule houses the spores

Question 6

(sporophytes of living moss)

What do the peristomal teeth do?

Answer 6

The peristomal teeth move back and forth depending on how moist or dry the conditions are.
When they dry out completely, they move the spores out forcefully dispersing them.

Question 7

(sphagnum moss)

In what type of environment does Sphagnum grow?

Answer 7

Bogs / wetlands

Question 8

(sphagnum moss)
Sphagnum had specialized dead cells that make it useful for hanging baskets and in potting media for many plants. What is the function of those dead cells?

Answer 8

The dead cells absorb and hold water

Question 9

(lycopodium life cycle)

How does the alternation of generations differ from that of nonvascular plants?

Answer 9

Sporophyte dominant, bisexual gametophyte

Question 10

(lycopodium life cycle)

What are strobili and where do they occur on the plant body?

Answer 10

Strobili: reduced spore-producing modified leaves (sporophylls) in a cluster at the tip of stems

Question 11

(cross section of lycopod stem)

What type of stele does it possess?

Answer 11

Protostele

Question 12

(resurrection plant)

Describe its roots and its overall morphology.

Answer 12

It has fibrous, adventitious roots and has a spreading flat form.

Question 13

(resurrection plant)

How does its structure look different from when it is wet to when it is dry?

Answer 13

When dry it is curled up and brown,

when wet it spreads out flat and starts to green up with chlorophyll

Question 14

(selaginella)

What type of branching does it have (is it dichotomous or does it have axillary buds)?

Answer 14

It has dichotomous branching

Question 15

(leptosporangiate fern life cycle)

How does it differ from that of the lycopods and Selaginella?

Answer 15

Sporangia are clustered in sori on the underside of sporophylls instead of in strobili.
The gametophyte generation is very short-lived, and most are homosporous.

Question 16

(leptosporangiate fern life cycle)
These ferns have colonies of nitrogen-fixing cyanobacteria that live in their leaves. Why do rice farmers have these ferns in their paddies?

Answer 16

The N-fixing bacteria in the leaves of the Azolla fix N from the atmosphere to make it available to the rice plants, especially when the Azolla die and decompose.

Question 17

(Look at a sporangium)(technically synangia because they are made up of multiple fused sporangia).
How many parts are there to each synangium?

Answer 17

There are 3 fused sporangium to each synangium

Question 18

(look at removed psilotum)

How do the rhizomes differ in appearance to the rest of the plant?

Answer 18

The rhizomes are thicker, brown and more irregular, while the rest of the plant is thinner, green and the stems are more uniform.

Question 19

(cross section of the psilotum stem)

What type of stele do these plants have?

Answer 19

Protostele

Question 20

(strobilus under a dissecting scope)

Can you identify individual sporangia?

Answer 20

yes

Question 21

Now hold a few Equisetum stems in your hand. Are they rough or smooth?
Explain why the stem feels that way

Answer 21

The Equisetum stems are rough because they have silica in their cell walls.

Question 22

lycopodiophyta have… which are?

Answer 22

microphylls which are one-unbranched vascular bundle

Question 23

selaginella =

Answer 23

resurrection plant

Question 24

resurrection plant unique characteristic

Answer 24

Poikilohydry: ability to loose 95% of their intracellular water and go dormant during dry seasons

Question 25

leptosporangiate venation

Answer 25

circinate venation

Question 26

leptosporangiate fern common name

Answer 26

young fiddlehead

Question 27

cluster of sporangia =

Answer 27

sorus

Question 28

plural of sorus

Answer 28

sori

Question 29

why are Equisetum stems green

Answer 29

The stems are photosynthe3c (the leaves are reduced and do not photosynthesize)