Question 1

Suppose that 100 pollen grains land on a stigma,and 50 mature seeds are formed in the fruit.What does this indicate about the pollination process and success?

Accepted Answer

A)  50% success: 100 pollen grains grew to 50 ovules,and double fertilization occurred
B)  50% success: evidently,only 50 sperm pollinated 50 anthers
C)  50% success: 50 sperm fertilized 50 eggs,and 50 sperm fused with 50 polar nuclei
D)  50% success: 50 sperm fertilized 50 eggs,and 50 sperm fused with 100 polar nuclei D

Question 2

What is an essential part of alternation of generations in plants?

Accepted Answer

A)  meiosis to produce gametes
B)  meiosis to produce gametophyte
C)  mitosis to produce gametes
D)  fertilization to produce spores
E)  fertilization to produce gametes C

Question 3

If a hypocotyl does not elongate during seed germination and early seedling growth,where will the cotyledons be?

Accepted Answer

A)  above ground and above the seed
B)  above ground and below the seed
C)  in the ground with the seed coat C

Question 4

Charles Darwin experimented with reactions of grass seedlings (monocots)relative to applied auxin (a plant hormone)and light.He used the youngest seedlings with a structure that dicots do not have.What is the name of that structure?

Accepted Answer

A)  coleoptile
B)  cotyledons
C)  radicle
D)  seed coat

Question 5

Which of these events occurs first in seed germination?

Accepted Answer

A)  Cell division occurs in the embryo,and growth starts.
B)  Mitochondria multiply and provide energy for growth processes.
C)  Water is taken up.
D)  Oxygen is produced and proteins are synthesized.
E)  New mRNAs and proteins are produced.

Question 6

The egg of a plant has a haploid chromosome number of 12 (n = 12).What is true about the number of chromosomes in the cells of other tissues of this plant?

Accepted Answer

A)  The sperm has 6 chromosomes.
B)  The leaves and stems have 12 chromosomes.
C)  The zygote has 12 chromosomes.
D)  The endosperm has 36 chromosomes.
E)  All of these answers apply.

Question 7

Which of these is not a step in the formation of an embryo from a zygote in the seed?

Accepted Answer

A)  The root and shoot systems emerge from the seed.
B)  Basal cells form a connection between the parent plant and the developing embryo.
C)  Mitosis produces a mass of cells that become the young embryo.
D)  Cells differentiate to form the basic plant tissue types.
E)  The early root-shoot axis is formed.

Question 8

Use the following information when answering the corresponding question(s).
Whitebark pine (Pinus albicaulis)is an important tree at timberline in the Rocky Mountains and Sierra Nevadas.Its large seeds provide food for grizzly bears,squirrels and other rodents,and many birds,including its major seed disperser,the Clark's nutcracker (Nucifraga columbiana).The Clark's nutcracker has a pouch below its tongue for carrying seeds,which it deposits 10 m to 12 km from a tree.Clark's nutcrackers often store many more seeds than they need for survival;in a single year,one bird can store more than 30,000 seeds.They store 3-5 seeds from one cone in each cache and typically use the seeds for food during spring and summer.When these birds do not harvest the seeds,the seeds germinate and form new whitebark pine trees.(D.F.Tomback.1982.Dispersal of whitebark pine seeds by Clark's nutcracker: A mutualism hypothesis.Journal of Animal Ecology 51:451-67. )
-Refer to the paragraph on whitebark pine seed dispersal by Clark's nutcracker.To conclude that the Clark's nutcracker is a mutualistic seed disperser,not just a predator,you would need to determine that _____.

Accepted Answer

A)  if the birds are not present,whitebark pine cannot spread
B)  the birds eat all the seeds they cache
C)  seeds in the caches can germinate to produce seedlings
D)  bears and squirrels do not eat any of the seeds

Question 9

A gardener in Canada wants to surprise his mother on her birthday and make her favorite Shrubalthea bush flower in May instead of the end of June.The bush is growing in the greenhouse.Which of the following might make the Shrubalthea bush flower early?

Accepted Answer

A)  fertilizing the bush
B)  grafting leaves of a Shrubalthea that was exposed to long night
C)  grafting leaves of a Shrubalthea that was exposed to short night
D)  exposing flower buds of the Shrubalthea bush to long nights
E)  exposing flower buds of the Shrubalthea bush to short nights

Question 10

The flowering hormone is made in _____ and alters development of _____.

Accepted Answer

A)  flowers;leaves
B)  flowers;root meristem
C)  leaves;apical meristem
D)  leaves;flowers
E)  roots;flowers

Question 11

Gardeners purchase packets of seeds that are put in the ground and germinate.Native plant seeds usually need a scarification treatment or a real or simulated winter (stratification),some seeds need light,and others need a smoke treatment.What do these adaptations to the environmental conditions reveal about where the plants grow?

Accepted Answer

The answer of Gardeners purchase packets of seeds that are...

Question 12

A researcher found a beautiful plant while traveling in Alaska and collected its seeds.When she came back to Florida,she soaked some seeds in pure water and some in water with the hormone gibberellin.When she put seeds to grow in soil,only seeds soaked with gibberellin germinated.The seeds that were soaked in pure water did not germinate because of _____.

Accepted Answer

A)  no exposure to a cool temperature period
B)  high concentration of ABA
C)  thick seed coat
D)  absence of nutrients in pure water
E)  Any of the above might have prevented germination.

Question 13

If an ovary contains 50 ovules,what is the minimum number of pollen grains that must land in order to form 50 mature seeds?

Accepted Answer

A)  25
B)  50
C)  100
D)  It is impossible to tell.

Question 14

You find a fruit that has little hooks around the outside of the pericarp.You can assume that _____ is/are the pollinator.

Accepted Answer

A)  wind
B)  birds
C)  mammals
D)  cannot answer based on the information given

Question 15

Cottonwood,aspen,and willow trees have beige flowers,with no petals,that appear before the tree's leaves are out in the spring;and they are dioecious.What does that indicate about these trees?

Accepted Answer

A)  Their insect pollinators are specialists.
B)  Early emerging insects are probably the pollinators.
C)  Their pollen is dispersed by wind.
D)  The trees are self pollinating.

Question 16

Unripe fruits protect seeds from predation and early germination.What is the major function of ripe fruits?

Accepted Answer

A)  attracting pollinators
B)  dispersing seed
C)  releasing nutrients to seeds
D)  keeping the seed hydrated before germination

Question 17

A summer occupation in the Corn Belt states is de-tasseling the corn:
Removing unwanted male flowers so that female flowers on the same plant are pollinated by the desired pollen for the hybrid corn.What does this tell you about corn?

Accepted Answer

A)  The flowers are perfect and the plant is dioecious.
B)  The flowers are perfect and the plant is monoecious.
C)  The flowers are imperfect and the plant is dioecious.
D)  The flowers are imperfect and the plant is monoecious.

Question 18

Pollen from a plant with the S₁S₂ genotype is recognized and allowed to germinate on the stigma of the same plant with the S₁S₂ genotype.According to the S-system hypothesis,this indicates that the plant is _____.

Accepted Answer

A)  self-compatible and can self-pollinate.
B)  self-compatible and must cross-pollinate.
C)  self-incompatible and can self-pollinate.
D)  self-incompatible and must cross-pollinate.

Question 19

The hammer orchids resemble female thyranide wasps and release a chemical signal called pheromone to deceive male thyranide wasps and accomplish pollination.Compared to food-deceiving orchids,is it more or less likely that pollen of hammer orchid will be transferred to the flower of the same species than to flower of the different species?

Accepted Answer

A)  more likely
B)  less likely
C)  similar probability

Question 20

Mosses and ferns tend to be most abundant in warm,moist climates.Why do mosses and ferns have problems with reproduction in deserts?

Accepted Answer

A)  Their pollen is not resistant to desiccation.
B)  Their seeds are not resistant to desiccation.
C)  Their sperm must swim for fertilization to occur.
D)  Their ovules need water for fertilization to occur.

Exam 40: Plant Reproduction