Exam I Practice Questions

Question 1

Which of the following adaptations in plants would not be well suited to a tropical rainforest environment?

Answer 1

a. Broad flat leaves b. Epiphytic habit c. Small reduced leaves d. Deciduous only in dry season e. Lack of freezing tolerance

Question 2

Which of the following plant types has a haploid (gametophyte) dominant life-cycle?

Answer 2

a. Gymnosperms b. Ferns c. Mosses d. Angiosperms e. All of the above

Question 3

Flowers are important innovations in the success of angiosperms because

Answer 3

a. they promote cross-pollination and gamete exchange b. they provide attractive decorations for gardens c. they make animals evolve d. they supply nutrients to the plant e. they promote seed dispersal

Question 4

Which of the following were important adaptations allowing plants to become terrestrial?

Answer 4

a. Chlorophyll b. Baseball bats c. gametophytes d. Motile male gametes e. None of the above

Question 5

Which tissue type is most likely to be involved in protecting plants against desiccation?

Answer 5

a. vascular tissue b. dermal tissue c. ground tissue d. xylem e.phloem

Question 6

Pollination results in delivery of sperm cells to the ovary after which what happens?

Answer 6

a. Fertilization occurs resulting in a triploid zygote b. Meiosis occurs resulting in 3 haploid zygotes c. Mitosis occurs resulting in a larger endosperm d. Double fertilization occurs resulting in a zygote and triploid endosperm e. Double fertilization occurs resulting in a diploid endosperm

Question 7

Meristems in plants are associated with ?

Answer 7

a. Growth of a plant from the apices b. Elongation of plant stems c. Outwards growth of dicots d. Production of bark e. All of the above

Question 8

Which of the following best describes photosynthesis in plants?

Answer 8

a. A process for releasing energy from carbohydrates b. A process involved in harnessing light energy to produce ATP and NADPH which is then used to fuel fixation of sugars into water and oxygen c. A process which harnesses light energy to produce ATP and NADPH which is then used to fuel fixation of carbon dioxide into organic compounds d. A process for synthesizing proteins using a sequence encoded on DNA e.A process which converts chlorophyll into oxygen, water and carbon dioxide

Question 9

Which of the following habitats is a perennial evergreen plant with narrow needle-like leaves with waxy covering likely to inhabit.

Answer 9

Taiga (boreal forests)

The evergreen conifers with their waxy needle-like leaves dominate in the taiga or boreal forests.

Question 10

Which kind of life cycle is typical of most animals?

Answer 10

Diploid dominant

most animals are diploid dominant i.e. the independent organism is diploid, while the gametes are haploid cells involved in excahnge of genetic material

Question 11

Which life cycle is found in ferns?

Answer 11

alternation of generation

Yes! Ferns are the classic example of alternation of generation, where both the diploid sporophyte and the haploid gametophyte are independent and macroscopic (although the prothallus gametophyte is much smaller than the sporophyte)- you looked at this in the lab.

Question 12

Which of these conclusions is supported by plant phylogenies (evolutionary trees)?

Answer 12

The oldest lineages of land plants are descended from some green algae (Charophytes)

This is true because of the oldest lineages are found in watery environments due to lack of vascular tissue and need for water in sexual reproduction. Also, the sister group to land plants, the Charophytes, are algae that live in fresh water.

Question 13

Solving the problem of the need for water in plant reproduction, which restricted plants to moist environments, was a major breakthrough in plant evolution. In what major group of plants did this first occur?

Answer 13

seed plants

In seed plants (gymnosperms and angiosperms), the male gametophyte is contained within pollen which is transported in various ways (wind, insects, etc.).

Question 14

Plants need to take in carbon dioxide from the atmosphere and release oxygen, but the waxy cuticle overlaying the epidermis of stems and leaves to prevent water loss also prevents the exchange of gases. What structure found in many plants was the solution to this problem?

Answer 14

stomata

The stomata consist of an opening surrounded by specialized guard cells. When the guard cells become taut, they open the pore, maximizing carbon dioxide intake and release of oxygen.

Question 15

The fossil record is important to our understanding of plant evolution. The oldest plant fossil dates to 475 million years ago, and the fossil record for land plants spans almost 60 million years, documenting the origin of land plants. What fossilized remains were found early in the record that helped plants adapt to land by reducing water evaporation?

Answer 15

sheets of waxy material called cuticle

Cuticle fossils are the earliest evidence of land plants

Question 16

Mosses, ferns, and clubmosses expand their geographic range by spore dispersal. What replaces spore dispersal in gymnosperms and angiosperms?

Answer 16

seeds

Seeds, either alone (gymnosperms) or in fruits (angiosperms) are the main method of dispersal in these groups.

Question 17

In the alternation of generations life cycle (e.g. ferns), the sporophyte produces:

Answer 17

spores

Question 18

In the alternation of generations life cycle, meiosis directly precedes the production of:

Answer 18

spores

spores germinate into the gametophyte (Prothallus) which produces the gametes via antheridia and archegonia

Question 19

In the alternation of generations life cycle, mitosis directly precedes the production of:

Answer 19

eggs and sperm, gametes

gametes are a collective term for egg and sperm. The gametes are produced in the antheridia and archegonia within the halpoid gametophyte (prothallus)

Question 20

The reason that mitosis can result in the production of haploid gametes in alternation of generations is because

Answer 20

Eggs and sperm are produced by the haploid gametophyte via mitosis

Question 21

In the fern life cycle, how does fertilization occur?

Answer 21

The gametophyte produces sperm and eggs in gametangia (antheridia and archegonia). The sperm reach the eggs by swimming through water

Question 22

The earliest land plants were most likely to have lived in which of the following habitats?

Answer 22

fresh water wetlands

land plants were believed to have evolved from freshwater algae, the Charophytes

Question 23

What is heterospory?

Answer 23

The production of two kinds of spores: the larger spores germinate into female gametophytes, the smaller spores germinate into male gametophytes

Question 24

In the life cycle of mosses, which of the following is true?

Answer 24

The sporophytic generation grows out of gametophytic tissue and is dependent on the green gametophyte for nutrition

this describes the gametophyte generation. Mosses are Haploid dominant.

Question 25

Which of the following innovations in seed plants did away with the need for water to effect fertilization?

Answer 25

pollen

Question 26

Which of the following innovations allowed plants to move into drier habitats?

Answer 26

embryo packaged in a seed pollen vascular tissue

The embryo is protected from desiccation (drying out) by the seed, pollen replaces the need for fertilization via water, cuticles also protect the earliest land plants from desiccation and vascular tissue allows water to be provided to aerial parts

Question 27

Which of the following group of adaptations are likely to be found in plants living in tropical rainforests?

Answer 27

Large spreading leaves, epiphyitc habit, lianas

Yes - many leaf adaptation are to improve light capture

Question 28

What is the best reason that tundra ecosystems do not support large trees

Answer 28

There is only a shallow layer of thawed soil to support roots

Yes - little support options for trees which need deep roots to for structural stability, and little options for uptake of water (and nutrients) when the water is frozen in permafrost

Question 29

Which of the following helps to explain the purpose of flowers?

Answer 29

Flowers are adaptations that increase the probability that pollination will occur

Flowers have many adaptations to ensure pollination. Among them is showy petals (or other floral parts), scent, nectar, and special markings to direct the pollinator to the interior of the flower. Plants that are pollinated by wind tend not to be showy, but do have characteristics that aid in the dispersal of pollen

Question 30

Which of the following is NOT part of the pollination process of flowering plants?

Answer 30

The egg contained within the female gametophyte is fertilized by a sperm cell contained within the male gametophyte

This describes fertilization, not pollination. Do not confuse the two.

Question 31

What adaptation found in vines and epiphytes aid in the capture of light for photosynthesis?

Answer 31

They take advantage of the structural support of trees to reach high in the canopy, where light levels are higher

This adaptation allows them to capture photons high above the ground without expending the energy and resources required to synthesize wood in the way that trees do.

Question 32

Which of the choices below are a prime characteristic of both the gymnosperms and angiosperms?

Answer 32

seeds

• Angiosperms and Gymnosperms form the Seed plants!*
• fruits and vessel elements are found only in angiosperms (with a minor exception for the Gnetales, which have vessel elements). Neither group has free swimming sperm*

Question 33

Which of the characteristics below are major evolutionary innovations found mainly in the angiosperms

Answer 33

fruit, flowers, double fertilization

Question 34

Which of the following is true of tracheids?

Answer 34

They are found in vascular tissue and conduct water and dissolved nutrients.

tracheids are xylem cells found in all seed plants (gymnosperms and angiosperms) and thus are important for conducting water from roots to aerial tissues.

Question 35

Which of the following is a major cell type that is totipotent?

Answer 35

parenchyma

Parenchyma is capable of cell division throughout the cell’s life

Question 36

Which of the following is true of seive tube members?

Answer 36

They conduct photosynthate (sugars) throughout the plant

seive tubes are part of vascular phloem

Question 37

Why is seed dormancy advantageous for many plants?

Answer 37

Plants can hold off on germination until environmental conditions are ideal for growth of the new seedling

Question 38

Which of the following are gymnosperms?

Answer 38

cycads, conifers, gnetophytes (Welwitschia, Ephedra, and Gnetum)

Question 39

Which of the following is a true statement about life cycles as we “go up” the plant evolutionary tree (i.e. from oldest to most recently evolved)?

Answer 39

Primitive non vascular land plants are gametophyte dominant with a dependent sporophyte, seedless vascular plants have alternation of generation (independent free-living sporophytes and gametophytes) and seed plants have dominant sporophytes with a dependent gametophyte

Remember the figure from lectures showing a transition from haploid dominant in algae, mosses, to half/half in ferns and diploid dominant in the seed plants

Question 40

In angiosperms, how is the female gametophyte formed?

Answer 40

A megaspore mother cell (megasporocyte) in the ovule undergoes meiosis to produce a megaspore which in turn develops by mitosis into a seven celled, eight nucleate female gametophyte

Question 41

When can you encounter monoecy and dioecy in flowering plants?

Answer 41

When plants have unisexual flowers (containing only stamens or only carpels but not both together)

Plants that have unisexual male and female flowers on the same plant are monoecious; plants that have unisexual male and female flowers on separate plants (male and female plants) are dioecious

Question 42

Which of the following plant cell types have thick secondary walls?

Answer 42

sclereids and fibers

collenchyma has thick primary walls, not secondary walls

Question 43

What is the main function of xylem?

Answer 43

moving water and dissolved nutrients from roots to shoots in the plant

Question 44

The vascular tissue, phloem, is made up of:

Answer 44

seive tube members and companion cells

this is an undifferentiated cell type found throughout the plant, especially in the leaves

Question 45

Which of the following organs have apical meristems?

Answer 45

roots and stems

apical meristems are found at the root tip and shoot tip and help elongate the plant in both directions

Question 46

What is the apical meristem?

Answer 46

The area at the apex of a stem or root that has parenchyma cells that continually divide, producing growth in length.

Question 47

What is an imperfect flower?

Answer 47

A flower that is missing either stamens or carpels

Quite a few flowers may be missing sepals or petals or have them fused, but this does not make the flower imperfect

Question 48

Which of the following is NOT true about fruit and seeds?

Answer 48

A fruit is a ripened ovule

A fruit is an ovule with surrounding carpel tissue

Question 49

If green plant cells are incubated with 14C-labeled carbon dioxide, what molecule will become radioactive as the cells are exposed to light?

Answer 49

sugar

a 14-C label cannot be converted into an oxygen label.

Question 50

If green plant cells are incubated with 18O-labeled water, what molecule will become radioactive as the cells are exposed to light?

Answer 50

oxygen

CO2 is fixed in the dark reactions, which are separate from the light reactions which use water to supply an electron to the electron tranport chain.

Question 51

Why is it possible for the Calvin cycle to occur in the dark?

Answer 51

The Calvin cycle uses energy (ATP and NADPH) stored previously during the light-dependent reactions of photosynthesis.

The stored energy is in the form of ATP adn NADPH. This allows the reactions of carbohydrate (sugar) synthesis and light absorption to occur in different compartments of the chloroplast.

Question 52

The light dependent reaction in photosynthesis occurs in which part of the chloroplast?

Answer 52

The thylakoid membranes

Solar energy is converted to chemical energy (ATP, NADPH) in the thylakoid membranes of the chloroplast

Question 53

Chlorophyll is green because:

Answer 53

it absorbs both blue and red light.

The light not absorbed is reflected and gives the plant its green color.

Question 54

What is the difference between the absorption spectrum and the action spectrum

Answer 54

The absorption spectrum plots a pigments ability to absorb light against wavelength; the action spectrum plots photosynthetic rate against wavelength

• “Plants have several different pigments which absorb light at different wavelengths. This allows plants to photosynthesize across a broader range of light conditions than if they only contained one pigment.*
• The absorption spectrum is the wavelengths which are absorbed and the actiion spectrum is what wavelengths are effective in driving photosynthesis”*

Question 55

How does the sequestering of carbon dioxide during the night in CAM plants help them to survive?

Answer 55

It allows carbon dioxide to be fixed at night and released within the plant for use during the day. This in turn allows the CAM plants to keep their stomata closed during the hot day.

Water can be conserved by opening stomata only during the night. CO2 is initially fixed and stored in a C4 acid at night, and then the CO2 is released during the day and fixed by the Calvin cycle. Keeping stomata closed during the day drastically reduces transpiration rate and water loss via the stomata.

Question 56

How do CAM plants differ from C4 plants?

Answer 56

The two steps involved in carbon fixation are separated spatially in C4 plants and temporally in CAM plants

CAM plants fix carbon at night and release it during the day, where it is fed into the Calvin Cycle. C4 plants fix carbon in certain mesophyll cells and release it into the bundle sheath cells, where it feeds into the Calvin Cycle.

Question 57

What is the difference between a C3 and C4 plant?

Answer 57

In a C3 plant, the first organic product of carbon fixation is a 3 carbon compound. In a C4 plant, the first organic product of carbon fixation is a 4 carbon compound.

The C4 plant can fix carbonmore efficiently under hot dry conditions because the enzyme (PEP) has a greater affinity for carbon dioxide. This allows the plant to keep its stomata open for shorter times during the day, reducing water loss through transpiration.

Question 58

Which of the following best describes the light reactions of photosynthesis?

Answer 58

Reactions in the thylakoid membranes to harvest light energy and produce ATP and NADPH