Deck 22: Early Development of the Plant Body

Question 1

When the zygote first divides, the two daughter cells are the ______ cell and the ______ cell.

A)micropylar; chalazal
B)root; shoot
C)apical; basal
D)proembryo; suspensor
E)axis; proembryo

Answer 1

C

Question 2

During embryogenesis in Arabidopsis, mutants with the twn mutation:

A)form no viable embryos.
B)produce no food reserves.
C)form secondary embryos from the suspensor.
D)produce a suspensor that dies prematurely.
E)produce a suspensor that loses its polarity.

Answer 2

C

Question 3

The cotyledons elongate most dramatically and may become curved during the _______ stage.

A)proembryo
B)torpedo
C)suspensor
D)heart
E)globular

Answer 3

B

Question 4

In some embryos, below the hypocotyl the _________ is found.

A)epicotyl
B)radicle
C)plumule
D)coletoptile
E)shoot apical meristem

Question 5

Which of following lists the correct developmental sequence in eudicots, where I is the globular stage; II, the heart stage; III, the proembryo; IV, the torpedo stage; and V, the zygote?

A)V, III, I, II, IV
B)I, V, IV, II, III
C)III, V, II, IV, I
D)V, I, III, II, IV
E)V, III, II, I, IV

Question 6

A plant's body plan consists of a(n) ______ and a(n) ______ pattern.

A)apical-radial; basal
B)apical-basal; radial
C)basal-radial; apical
D)apical; basal
E)radial; apical

Question 7

During early embryogenesis, the ground meristem surrounds the:

A)epidermis.
B)procambium.
C)protoderm.
D)epidermis.
E)ground tissues.

Question 8

Which of the following statements concerning primary meristems is FALSE?

A)An example is the suspensor.
B)An example is the procambium.
C)An example is the ground meristem.
D)They are formed during embryogenesis.
E)They are meristematic.

Question 9

Which of the following statements about the polarity of an embryo is FALSE?

A)It fixes the structural axis of the body.
B)It is established only after the zygote has divided.
C)It is essential to the development of all higher organisms.
D)It refers to the condition in which one end is different from the other end.
E)It is a key component of biological pattern formation.

Question 10

In eudicots, in which most of the endosperm is absorbed by the embryo, the cotyledons:

A)are large and fleshy.
B)are thin and membranous.
C)develop into the scutellum.
D)are absent.
E)absorb stored food during resumption of embryonic growth.

Question 11

Where does the shoot apical meristem arise in eudicot embryos?

A)at the tip of a sheathlike extension
B)at the tip of a cotyledon
C)on one side of the single cotyledon
D)on one side of the two cotyledons
E)between the two cotyledons

Question 12

Normal development of the ______ prevents formation of extra embryos by the ______.

A)embryo proper; apical meristems
B)primary meristems; embryo proper
C)suspensor; apical meristems
D)embryo proper; suspensor
E)suspensor; embryo proper

Question 13

The procambium is the precursor of the:

A)epidermis.
B)ground tissues.
C)protoderm.
D)xylem and phloem.
E)primary meristems.

Question 14

The stem-like axis above the cotyledon(s) is the:

A)epicotyl.
B)hypocotyl.
C)plumule.
D)funiculus.
E)radicle.

Question 15

In Arabidopsis, embryonic development is thought to be coordinated by at least ______ distinct genes.

A)50
B)150
C)350
D)550
E)750

Question 16

Which primary meristem forms first?

A)shoot apical meristem
B)root apical meristem
C)ground meristem
D)protoderm
E)procambium

Question 17

Located at the micropylar pole of the embryo is the:

A)apical cell.
B)embryo proper.
C)proembryo.
D)protoderm.
E)basal cell.

Question 18

Which of the following CANNOT be part of the plumule?

A)shoot apical meristem
B)young leaves
C)radicle
D)epicotyl
E)stem-like axis

Question 19

In embryogenesis in monocots, globular embryos next become:

A)two-lobed.
B)curved.
C)cylindrical.
D)heart-shaped.
E)spherical.

Question 20

The root and shoot apical meristems first become discernible during the transition between the ______ and ______.

A)proembryo; globular stage
B)torpedo stage; proembryo
C)heart stage; globular stage
D)globular stage; torpedo stage
E)torpedo stage; embryo proper

Question 21

Which of the following events is NOT associated with seed germination?

A)imbibition
B)activation of existing enzymes
C)synthesis of new enzymes
D)synthesis of food reserves
E)initiation of cell division and cell enlargement

Question 22

The integuments develop into the:

A)hilum.
B)seed coat.
C)funiculus.
D)coleoptile.
E)endosperm

Question 23

Which of the following statements concerning the maturation phase of seed development is FALSE?

A)The seed undergoes desiccation.
B)Food reserves accumulate in the endosperm and/or cotyledons.
C)The seed coat hardens.
D)Starch, proteins, and oils accumulate.
E)Cell division in the embryo accelerates.

Question 24

In monocots, the cotyledon can have all of the following functions EXCEPT:

A)protection of the plumule.
B)photosynthesis.
C)absorption of nutrients.
D)storage of nutrients.
E)transport of nutrients.

Question 25

In temperate regions of the world, after-ripening is triggered by:

A)drought.
B)high humidity.
C)low temperature.
D)high temperature.
E)low oxygen levels.

Question 26

Which of the following would not typically cause coat-imposed dormancy?

A)impermeability of the seed coat to water
B)impermeability of the seed coat to oxygen
C)prevention of the release of growth promoters from the seed
D)rigidity of the seed coat
E)prevention of the release of growth inhibitors from the seed

Question 27

What induces the seeds of manzanita and other plants of the California chaparral to germinate?

A)light
B)fire
C)rainfall
D)activity of digestive enzymes
E)low temperature

Question 28

The ______ is usually the first structure to emerge from a germinating seed.

A)epicotyl
B)hypocotyl
C)cotyledon
D)root
E)coleoptile

Question 29

In epigeous germination, which structure emerges above ground first?

A)cotyledon
B)epicotyl
C)hypocotyl
D)coleoptile
E)radicle

Question 30

In monocots, the root system commonly develops from:

A)branch roots.
B)stem-borne roots.
C)the primary root.
D)the secondary root.
E)the taproot.

Question 31

In the pea (Pisum sativum), the ______ forms the hook that pushes to the soil surface during seed germination.

A)coleoptile
B)cotyledon
C)hypocotyl
D)epicotyl
E)radicle

Question 32

When the seed coat is ruptured during germination, the seed:

A)switches to anaerobic glucose breakdown.
B)switches to aerobic respiration.
C)first begins to use glucose as a fuel molecule.
D)no longer uses glucose as a fuel molecule.
E)is no longer able to use oxygen.

Question 33

In a grass embryo, the coleorhiza encloses the:

A)scutellum.
B)hypocotyl.
C)radicle.
D)epicotyl.
E)plumule.

Question 34

The process of after-ripening involves:

A)enzymatic modification of a dormant seed so that it will germinate.
B)biochemical conversion of a germinating seed to a dormant seed.
C)cessation of the flow of nutrients from the parent plant to the ovule.
D)stimulation of the primary meristems to develop.
E)desiccation and hardening of the seed coat.

Question 35

Which of the following statements about the seed coat is FALSE?

A)It develops from the ovary.
B)It protects the embryo.
C)It may be papery or very hard.
D)It may be impermeable to water.
E)The micropyle may be visible on the seed coat.

Question 36

A quiescent seed is different from a dormant seed in that a quiescent seed will germinate:

A)when hydrated.
B)under anaerobic conditions.
C)in the presence of growth inhibitors.
D)when the embryo is physiologically immature.
E)under suboptimal temperature conditions.

Question 37

The cotyledon of grasses is called a(n):

A)scutellum.
B)hypocotyl.
C)epicotyl.
D)coleorhiza.
E)hilum.

Question 38

The scar left on the seed coat after the seed has separated from its stalk is called the:

A)micropyle.
B)funiculus.
C)hilum.
D)suspensor.
E)integument.

Question 39

Embryo dormancy would typically be caused by:

A)unfavorable external conditions.
B)the seed coat preventing the release of abscisic acid.
C)an increase in gibberellic concentrations.
D)a decrease in abscisic acid concentrations.
E)an increase in abscisic acid concentrations.

Question 40

In grasses, the pericarp consists of the:

A)mature ovary wall only.
B)remnants of the seed coat only.
C)remnants of the scutellum only.
D)mature ovary and remnants of the seed coat only.
E)mature ovary, remnants of the seed coat, and remnants of the scutellum.

Question 41

The coleoptile and coleorhiza are typically found in monocots and eudicots.

Question 42

The suspensor is an example of a structure that undergoes programmed cell death.

Question 43

In maize (Zea mays), the first structure to emerge from the seed during germination is the:

A)epicotyl.
B)hypocotyl.
C)radicle.
D)coleorhiza.
E)coleoptile.
True-False Questions

Question 44

In angiosperms, polarity can be established either with the first division of the zygote or before.

Question 45

In the heart stage of development, the lobes of the "heart" are the cotyledons.

Question 46

The apical meristems are the source of virtually all of the tissues of the seedling and adult plant.

Question 47

In a grass embryo, the coleoptile encloses the plumule.

Question 48

The embryonic root is called the radicle.

Question 49

The funiculus is the stalk of the seed.

Question 50

The radial pattern of embryogenesis consists of concentrically arranged tissue systems.

Question 51

The root and shoot apical meristems are two of the primary meristems.

Question 52

Metabolism increases toward the end of the maturation phase of seed development.

Question 53

In grasses, the pericarp is found immediately inside the seed coat.

Question 54

Which of the following statements about seed germination in onion (Allium cepa) is FALSE?

A)Germination is hypogeous.
B)The plumule emerges from the cotyledon.
C)The cotyledon becomes photosynthetic.
D)The cotyledon forms the hook.
E)The stored food is found in the endosperm.

Question 55

Seeds with large cotyledons typically have little or no endosperm.

Question 56

The protoderm is formed by anticlinal divisions of the outermost cells of the embryo proper.

Question 57

The suspensor anchors the embryo at the micropyle.

Question 58

The suspensor is part of the embryo proper.

Question 59

The cotyledon of grasses is called a scutellum.

Question 60

In most angiosperms, the first division of the zygote is symmetrical and longitudinal to the long axis of the zygote.

Question 61

The dormancy acquired during seed maturation is called primary dormancy.

Question 62

An example of coat-imposed dormancy is a mechanically rigid seed coat.

Question 63

In hypogeous germination, the cotyledons remain in the soil.

Question 64

Before a seed can germinate, it must first imbibe water.

Question 65

In temperate regions, after-ripening ensures that seeds will germinate in the fall rather than in the spring.

Question 66

Before the seed coat ruptures during germination, glucose breakdown may be entirely anaerobic.

Question 67

A quiescent seed will not germinate even when external conditions are favorable.