Deck 23: An Introduction to Plant Development

Question 1

The auxin produced in Arabidopsis embryos and Bicoid protein produced in Drosophila embryos have what similar function?

A)Both are regulatory transcription factors that serve as cell-to-cell signals.
B)Both are cytoplasmic determinants-they are loaded into eggs by cells in the mother or by female reproductive tissues.
C)Both trigger the transcription of homeotic loci-genes that specify the types of structures produced at a certain position.
D)Both establish a concentration gradient that demarcates the anterior-posterior axis.

Answer 1

D

Question 2

The ABC model of flower development suggests that

A)each of the three genes codes for the formation of a different flower organ.
B)genes may work alone or together to form different flower organs.
C)inactivation of genes may transform one organ into another.
D)both B and C are correct.
E)Answers A,B,and C are correct.

Answer 2

D

Question 3

In flowering plants,an event known as double fertilization occurs when

A)two sperm enter the ovule;one fertilizes the egg,and the other fertilizes a 2n cell to generate endosperm.
B)two sperm cells fertilize one normal egg cell to make a 3n embryo,and the embryo later becomes 2n during a unique mitotic division.
C)two eggs are simultaneously fertilized by two sperm nuclei.
D)None of the above apply.

Answer 3

A

Question 4

Plant embryos cannot undergo gastrulation.What ensures the correct positioning of cells during plant embryogenesis?

A)cell movements inside the seed coat
B)genetic differences among the cells
C)cytoplasmic determinants in the cells
D)different cell sizes and planes of mitosis
E)expansion of the cotyledons

Question 5

Auxin has an effect on plant embryos much like the Bicoid protein in Drosophila.If auxin were added to a culture of embryonic root cells,what is the likely result?

A)Root cells would elongate and mature.
B)Root cells would change into meristem cells.
C)Root cells would halt their development.
D)Root cells would not respond to auxin.

Question 6

Many flowering plant species have elaborate mechanisms to prevent an individual's pollen from fertilizing its own egg cells.Why?

A)to prevent inbreeding
B)to prevent polyspermy
C)to prevent cross-species fertilization and the production of dysfunctional hybrid offspring
D)to prevent double fertilization and the formation of endosperm

Question 7

The monopterous gene in Arabidopsis encodes a protein that is similar in its function to which animal protein?

A)MyoD in frog embryos
B)Bicoid in fruit-fly embryos
C)keratin in human embryos

Question 8

In the early plant embryo,cells divide asymmetrically.Which structure does NOT result from divisions of the apical cell?

A)the suspensor
B)the cotyledons
C)the hypocotyls
D)the shoot

Question 9

The ABC genes in Arabidopsis are considered homeotic genes.What could be a reason for this classification?

A)Each of the three genes codes for a different flower organ.
B)Each gene codes for regulatory transcription factors.
C)Each gene is similar in sequence to homeotic genes in Drosophila.
D)Each gene codes for proteins similar to Hox genes in mice.
E)Each gene directs different kinds of morphogenesis.

Question 10

If the expression of the PHAN gene is blocked in plants,what will be the likely result?

A)Plants will fail to develop leaves.
B)Plants will develop more leaves than usual.
C)Plants will develop leaves in very simple shapes.
D)Plants will develop leaves in inappropriate places.

Question 11

The basal cell in a plant embryo

A)develops from the root of the embryo.
B)forms the suspensor that anchors the embryo.
C)differentiates after gastrulation.
D)divides to form cotyledons.
E)divides to form hypocotyls.

Question 12

Of the following developmental processes,which is not undergone by plant embryos?

A)fertilization
B)cleavage
C)embryogenesis
D)gastrulation
E)organogenesis

Question 13

What does the ABC model of flower development attempt to explain?

A)how different combinations of gene products trigger the formation of different floral organs
B)why petals are found on the inside of the whorl of sepals instead of on the outside
C)why the four types of floral organs occur in whorls
D)why apical meristems are converted to floral meristems in response to specific cell-to-cell signals

Question 14

One unique feature of fertilization in flowering plants compared with animals is that

A)plant sperm are motile.
B)multiple ovules exist in the ovary.
C)the process involves double fertilization.
D)nuclear fusion does not take place.
E)the gametes are diploid,not haploid.

Question 15

Meristematic tissue cells in plants are MOST similar to which kind of cells in animals?

A)somite cells
B)ectodermal cells
C)embryonic stem cells
D)mesodermal cells

Question 16

The floral meristem in flowering plants develops from the shoot apical meristem,which usually produces leaves.Which floral part is not a modified leaf?

A)sepal
B)carpel
C)stamen
D)receptacle
E)petal

Question 17

Yolk and endosperm share a number of functions.Which of the following does NOT describe a similarity between them?

A)Yolk and endosperm both provide nutrition for embryos.
B)Yolk and endosperm both contain proteins.
C)Yolk and endosperm are both the result of a second fertilization process.
D)Yolk and endosperm are both cellular products.

Question 18

Organs in developing flowers include all of the following EXCEPT

A)whorls.
B)sepals.
C)petals.
D)carpels.
E)stamens.

Question 19

Interactions between proteins on the surface of the pollen grain and on the surface of the stigma are necessary for fertilization to proceed.What is the correct sequence of events that follow this interaction?

A)growth of pollen tube,double fertilization,formation of sperm
B)formation of sperm,growth of pollen tube,double fertilization
C)double fertilization,growth of pollen tube,formation of sperm
D)formation of sperm,double fertilization,growth of pollen tube
E)growth of pollen tube,formation of sperm,double fertilization

Question 20

All of the following statements are true of the endosperm except that

A)it may be likened to the yolk of an animal egg.
B)it is a triploid tissue.
C)it is used as a food source by the embryo.
D)it is formed from equal contributions of both parents.
E)it is the major energy source for germination.

Question 21

How do plants cope with the considerable variation in their environment?

A)Plants continually grow and take in cues from their environment,which alter their growth patterns in specific directions.
B)Plants have reproductive meristems that allow them to reproduce in response to poor conditions.
C)Plants have meristems that allow the plant to grow in more suitable conditions.
D)Plants undergo limited development and cannot adjust to changes in their environment.

Question 22

An elm tree is heavily shaded on one side due to growth of a nearby tree.How would the elm respond to such a change in its environment?

A)The elm tree cannot respond as only animals can respond to their environment.
B)The elm tree would stop growing on the shaded side and grow more on the unshaded side.
C)The elm tree would stop growing because of a lack of sunlight.
D)The elm tree would become dormant until the nearby tree died.

Question 23

Figure 23.1
On the figure above,which of the letters represents the apical axis?

A)A
B)B
C)C

Question 24

What effect does PHANTASTICA have on plant development?

A)It induces leaf growth within a shoot apical meristem.
B)It triggers transcription factors specific to the developing hypocotyl.
C)It triggers the expression of genes that cause cells to form the upper surface of leaves.
D)It induces growth of root apical meristems when nutrients are limited.

Question 25

How does the interaction between pollen and stigma in flowering plants compare to the interaction between bindin and its egg-cell receptor in sea urchins?

A)The specificity between these interactions prevents fertilization from occurring between members of different species.
B)The specificity between these interactions promotes self-fertilization (the union of sperm and egg from the same individual).
C)The specificity between these interactions promotes double fertilization.

Question 26

Which of the following would be attributed to a lack of meristems?

A)MONOPTEROS would no longer be activated leading to underdeveloped hypocotyls.
B)The roots and shoots would only respond to certain environmental cues (i.e.a lack of water).
C)Further growth of the plant would not occur.
D) Cells would only differentiate into vascular and epidermal tissue.

Question 27

Figure 23.1
Which of the following axes in the plant are analogous to the anterior-posterior axis in an animal?

A)lateral axis
B)adaxial-abaxial axis
C)proximal-distal axis
D)apical-basal axis

Question 28

Which of the following is correct regarding sperm cell development in Arabidopsis?

A)Sperm are produced by mitotic division of a haploid cell within the pollen grain.
B)Sperm are produced by meiotic divisions of a diploid cell within the male plant.
C)Sperm are produced by meiotic divisions of a haploid cell within a pollen grain on the male plant.
D)Sperm are produced by mitotic divisions of a diploid cell once the pollen has landed on the stigma.

Question 29

In their study of the Madagascar lace plant,how did the researchers establish that the holes were formed through programmed cell death?

A)They tested for apoptosis using the TUNEL assay.
B)They found suberin around the margins of the holes.
C)They found no nutrients in the cells forming the hole.
D)They tested for a waxy substance that triggered programmed cell death.

Question 30

Which of the following would be a logical hypothesis for advantage(s)to holes in the leaves of the Madagascar lace plant?

A)Holes in the leaves allow increased surface area for herbivores.
B)Holes in the leaves make it harder for competing plant species to see this plant.
C)Holes in the leaves reduce the amount of food available to herbivores.
D)Holes in the leaves increase the surface area to volume ratio of the plant.

Question 31

Plant and animal development share a number of features,but differ in major ways as well.Which of the following best summarizes the similarities between the two forms of development?

A)Both plants and animals develop from a process of single fertilization.
B)Both plants and animals produce specialized tissues through irreversible processes of determination and differentiation.
C)Both plants and animals produce gametes via meiosis followed by mitosis of haploid cells.
D)Both plant and animal development depends on precise control of gene expression in time and in space.

Question 32

Why is it advantageous for plants to have more than one shoot apical meristem (SAM)and more than one root apical meristem (RAM)?

A)Multiple SAMs and RAMs provide plants with the ability to deal with environmental changes in terms of resource availability.
B)Multiple SAMs and RAMs allow plants to decide where and when they should grow.
C)If one SAM or RAM doesn't function properly/got eaten,another SAM or RAM can take over.
D)All of A,B,and C
E)Both A and C.

Question 33

Figure 23.1
On the figure above,which of the letters represents the radial axis?

A)A
B)B
C)C

Question 34

Figure 23.2
Please refer to the elm tree shown in the figure above.What would be the likely phenotype of an elm that has the same genotype but grows in a forest?

A)Both elms have the same genotype and thus would look exactly the same as the one in the figure.
B)Because of competition for light,the elm in the forest would likely be taller and would not have as much growth to the sides.
C)Because of shading,the elm in the forest would likely be the same height as in the figure above,but would have less growth to the sides.
D)Because of competition for resources,the elm in the forest would be shorter and would have more growth to the sides.

Question 35

If auxin was not present in a developing plant cell,which of the following would most likely occur?

A)It would trigger activation of MONOPTEROS and other regulatory factors specific to cells in the developing hypocotyls.
B)It would trigger activation of MONOPTEROS and other regulatory factors specific to cells in the developing cotyledons.
C)It would trigger activation of MONOPTEROS and other regulatory factors specific to cells in the developing root apical meristem.
D) It would trigger activation of MONOPTEROS and other regulatory factors specific to cells in the developing shoot apical meristem.

Question 36

Plant and animal development share a number of features,but differ in major ways as well.Which of the following best summarizes the differences between the two forms of development?

A)Animal tissues are irreversibly differentiated;plant tissues retain plasticity throughout life.
B)Animal cells frequently undergo programmed cell death;plant cells do not.
C)Animal development is controlled by regulatory gene sets such as Hox genes;plants have no similar control systems.
D)Animal gametes are produced only after maturity is reached;plant gametes can be produced throughout a plant's lifetime.

Question 37

To what is the "double" part of double fertilization in flowering plants referring?

A)Two sperm penetrate and fertilize the egg at the same time.
B)Two sperm fertilize one egg each,producing two embryos.
C)One sperm fertilizes the egg to form the embryo,and,after several cell divisions,a second sperm fertilizes the same egg forming another embryo.
D)There are two fusion events involving separate sperm: one fuses with the egg forming an embryo,the other with a cell to form the endosperm.