Question 1

If intelligent extraterrestrials visited Earth 475 million years ago, and then again 300 million years ago (at the close of the Carboniferous period), what trends would they have noticed in Earth's terrestrial vegetation over this period? 1. a trend from dominant gametophytes to dominant sporophytes
2. a trend from sporangia borne on modified leaves (sporophylls)to sporangia borne on stalks (seta)
3. a trend from no true leaves, to microphylls, to megaphylls
4. a trend from soil-surface-hugging plants to "overtopping" plants
5. a trend toward increased lignification of conducting systems

Accepted Answer

A) 1 and 3 
B) 3, 4, and 5 
C) 1, 2, 4, and 5 
D) 1, 3, 4, and 5 
E) 2, 3, 4, and 5

Question 2

Which of the following is a true statement about plant reproduction?

Accepted Answer

A) Embryophytes are small because they are in an early developmental stage. 
B) Both male and female bryophytes produce gametangia. 
C) Gametangia protect gametes from excess water. 
D) Eggs and sperm of bryophytes swim toward one another. 
E) Bryophytes are limited to asexual reproduction.

Question 3

Which of the following is true of seedless vascular plants?

Accepted Answer

A) Extant seedless vascular plants are larger than the extinct varieties. 
B) Whole forests were dominated by large, seedless vascular plants during the Carboniferous period. 
C) They produce many spores, which are really the same as seeds. 
D) The gametophyte is the dominant generation. 
E) Sphagnum is an economically and ecologically important example.

Question 4

Beginning with the germination of a moss spore, what is the sequence of structures that develop after germination? 1. embryo
2. gametes
3. sporophyte
4. protonema
5. gametophore

Accepted Answer

A) 4 →1 → 3 → 5 → 2 
B) 4 → 3 → 5 → 2 → 1 
C) 4 → 5 → 2 → 1 → 3 
D) 3 → 4 → 5 → 2 → 1 
E) 3 → 1 → 4 → 5 → 2

Question 5

What is thought to be the correct sequence of the following events during the Carboniferous period? 1. vascular plants become more prevalent
2. megaphylls with large surface areas become more prevalent
3. atmospheric CO₂ levels decline by a factor of five
4. global cooling occurs, leading to widespread glaciations

Accepted Answer

A) 1, 2, 3, 4 
B) 2, 1, 3, 4 
C) 2, 1, 4, 3 
D) 1, 2, 4, 3 
E) 3, 4, 1, 2

Question 6

Which of the following were probably factors that permitted early plants to successfully colonize land? 1. the relative number of potential predators (herbivores)
2. the relative number of competitors
3. the relative availability of symbiotic partners
4. air's relative lack of support, compared to water's support

Accepted Answer

A) 1 and 2 
B) 2 and 3 
C) 3 and 4 
D) 1, 2, and 3 
E) 1, 2, and 4

Question 7

Which event during the evolution of land plants probably made the synthesis of secondary compounds most beneficial?

Accepted Answer

A) the greenhouse effect present throughout the Devonian period 
B) the reverse-greenhouse effect during the Carboniferous period 
C) the association of the roots of land plants with fungi 
D) the rise of herbivory 
E) the rise of wind pollination

Question 8

Which of the following structures are in the gametophyte generation of a moss?

Accepted Answer

A) buds, leaves, spores, rhizoids 
B) egg, sperm, zygote, sporangium 
C) antheridia, archegonia, egg, sperm 
D) foot, seta, spores, sporangium

Question 9

You are hiking in a forest and happen upon a plant featuring a central stemlike structure from which sprout many, tiny, leaflike structures. Which of the following would be the most certain means of distinguishing whether it was a true moss or a club moss?

Accepted Answer

A) its colour 
B) its height 
C) if seeds are present 
D) if conducting tissues are present 
E) the appearance of its spore-producing structures

Question 10

Which of the following should have had gene sequences most similar to the charophyte that was the common ancestor of the land plants?

Accepted Answer

A) early angiosperms 
B) early bryophytes 
C) early gymnosperms 
D) early lycophytes 
E) early pterophytes

Question 11

What is true of charophytes?

Accepted Answer

A) They are the ancestors of green algae. 
B) They are examples of seedless vascular plants. 
C) They are the closest living algal relatives of land plants. 
D) They share some features in common with land plants, namely spores surrounded by sporopollenin and alternation of generations.

Question 12

Which of the following is true of the life cycle of mosses?

Accepted Answer

A) The haploid generation grows on the sporophyte generation. 
B) Spores are primarily distributed by water currents. 
C) Antheridia and archegonia are produced by gametophytes. 
D) The sporophyte generation is dominant. 
E) The growing embryo gives rise to the gametophyte.

Question 13

Of the following list, flagellated (swimming)sperm are generally present in which groups? 1. Lycophyta
2. Bryophyta
3. Angiosperms
4. Chlorophyta
5. Pterophyta

Accepted Answer

A) 1, 2, and 3 
B) 1, 2, 4, and 5 
C) 1, 3, 4, and 5 
D) 2, 3, and 5 
E) 2, 3, 4, and 5

Question 14

The functional role of sporopollenin is primarily to

Accepted Answer

A) comprise spore surface structures that catch the wind and assist in spore dispersal. 
B) reduce dehydration. 
C) make spores less dense and able to disperse more readily. 
D) repel toxic chemicals. 
E) provide nutrients to spores.

Question 15

The next few questions are based on the following description.
A biology student hiking in a forest happens upon an erect, 15-cm-tall plant that bears microphylls and a strobilus at its tallest point. When disturbed, the cone emits a dense cloud of brownish dust. A pocket magnifying glass reveals the dust to be composed of tiny spheres with a high oil content.
-This student has probably found a(n)

Accepted Answer

A) immature pine tree. 
B) bryophyte sporophyte. 
C) fern sporophyte. 
D) horsetail gametophyte. 
E) lycophyte sporophyte.

Question 16

During glacial periods in the early evolution of land plants, which of the following would have been a beneficial adaptation regarding the number of stomata per unit surface area, and what accounts for it?

Accepted Answer

A) increased numbers of stomata, to maximize absorption of increasing levels of atmospheric CO₂ 
B) increased numbers of stomata, to maximize ability to absorb low levels of atmospheric CO₂ 
C) decreased numbers of stomata, to retain CO₂ produced by the chloroplasts 
D) decreased numbers of stomata, to maximize absorption of low levels of atmospheric CO₂

Question 17

Arrange the following terms from most inclusive to least inclusive. 1. embryophytes
2. green plants
3. seedless vascular plants
4. ferns
5. tracheophytes

Accepted Answer

A) 1, 2, 5, 3, 4 
B) 2, 1, 5, 3, 4 
C) 2, 5, 1, 3, 4 
D) 1, 4, 2, 5, 3 
E) 2, 1, 5, 4, 3

Question 18

Assuming that they all belong to the same plant, arrange the following structures from largest to smallest (or from most inclusive to least inclusive). 1. spores
2. sporophylls
3. sporophytes
4. sporangia

Accepted Answer

A) 2, 4, 3, 1 
B) 2, 3, 4, 1 
C) 3, 1, 4, 2 
D) 3, 4, 2, 1 
E) 3, 2, 4, 1

Question 19

Which of the following statements is true of archegonia?

Accepted Answer

A) They are the sites where male gametes are produced. 
B) They may temporarily contain sporophyte embryos. 
C) They are the same as sporangia. 
D) They are the ancestral versions of animal gonads. 
E) They are asexual reproductive structures.

Question 20

On a field trip, a student in a marine biology class collects an organism that has differentiated organs, cell walls of cellulose, and chloroplasts with chlorophyll a. Based on this description, the organism could be a brown alga, a red alga, a green alga, a charophyte recently washed into the ocean from a freshwater or brackish water source, or a land plant washed into the ocean. The presence of which of the following features would definitively identify this organism as a land plant?

Accepted Answer

A) alternation of generations 
B) sporopollenin 
C) rings of cellulose-synthesizing complexes 
D) flagellated sperm 
E) embryos

Exam 29: Plant Diversity I: How Plants Colonized Land