Plant Developmental Genetics Flashcards Preview

Developmental Genetics > Plant Developmental Genetics > Flashcards

Flashcards in Plant Developmental Genetics Deck (81):
1

Why is the arabidopsis plant used as a model organism?

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2

What are the three methods to transform plants (arabidopsis)?

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3

Three methods to altering gene expression in plants via transgenes?

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4

Describe the process of ectopic expression.

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5

What are the methods of silencing gene expression via trangenes and describe the process?

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6

Explain the method for turning snapdragon seeds yellow.

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7

What are some other examples of knockout expression?

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8

Describe the process of genome editing via the CRISPR/cas9 system.

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9

What is a meristem?

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10

What is the difference between an inflorescence meristem and a floral meristem?

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11

What are the three defining features of the shoot meristem?

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12

Describe the characteristics of Tunica and Corpus arrangement.

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13

Describe the arrangement of zones within the shoot meristem?

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14

What is a piece of evidence for the shoot meristem contributing to continuous organ growth?

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15

Define stem cells.

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16

Where are stem cells located in the meristem?

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17

What is the effect of colchicine on stem cells?

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18

How many stem cells are there in the meristem?

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19

What is the function of each zone?

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20

What is the example for multiple stem cells within the meristem?

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21

What are mutants that make no stem cells?

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22

What is WUS?

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23

What is STM?

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24

What are the CLAVATA mutants?

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25

Draw a diagram for the area of expression of the mutants?

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26

What does the ectopic expression of WUS lead to? What can be concluded from this?

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27

What does the ectopic expression of STM lead to? What can be concluded from this?

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28

What is the combined result of STM and WUS expression together?

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29

True or False?
WUS and STM act on the same pathway?

False, they act on different pathways.

30

What does the overexpression of CLV3 result in?

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31

What is the function of the CLV signal?

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32

Describe the negative feedback loop system of Clv3 and WUS.

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33

How does the Clv signal limit the size of the organising centre?

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34

What does CLV1,2,3 and WUS encode for?

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35

How is a feedback mechanism to control WUS expression formed?
Draw the diagram.

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36

In regards to the meristem, what happens if WUS is turned off?

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37

In regards to the meristem, what happens if there is too much CLV3.

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38

Summary:
What are the components of the shoot meristem feedback model?

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39

What are the LOF mutant phenotypes involved in the shoot meristem feedback?

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40

What is the relationship between Clv3 and Wuschel?

Clv3 is a repressor of Wuschel.

41

True or False?
Wuschel embryos fail to develop stem cells?

True.

42

True or False?
Clv3 embryos accumulate WUS expressing cells.

True.

43

What is the ZWILLE gene and what does it encode?

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44

What is the effect of Zll embryos on WUS and Clv3?

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45

What cells promote and antagonist stem cell maintenance?

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46

Describe the vegetative and floral transition of the meristem?

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47

How are floral organs arranged?

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48

Which homeotic mutants affect floral development?

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49

Define homeotic genes?

Homeotic genes are genes which regulate the development of anatomical structures in various organisms such as insects, mammals, and plants. This regulation is done via the programming of various transcription factors by the homeotic genes, and these factors affect genes through regulatory genetic pathways.

50

True or False?
ap1, ap2, ap3, pi and ag are all transcription factors.

True.

51

True or False?
ap1, ap2, ap3, pi and ag are active in 4 whorls.

False, they are only active in 2 whorls.

52

Can you turn on specific genes for a specific organ with different combinations of expression?

With the appropiate combination, they can turn on a gene to specify a given organ.

53

Describe the ABC model for floral development.

Each class of genes of genes are expressed in two whorls. with A
and C genes repressing each other.

Table for Class/Genes/Organ

54

Describe the outcome of LOF experiments on the ABC model.

LOF of A - C spreads (Carpels + Stamens)

LOF of B - Lose B (Sepals and Carpels)

LOF of C - A spreads ( Sepals + Petals)

55

True or False?
AP2 is only expressed in the cells that they function in?

False, they are expressed in all whorls, but only function in 1 and 2.

56

How is the AP2 protein controlled? What was the experiment conducted?

Post-transcriptionally regulated (Translational Control)

Comparing RNA and protein levels, RNA was found in all 4 whorls but the protein was only found in W1 and W2.

miRNA muts. show reduced Class C activity and increased A activity.

57

What are microRNAs and their function?

Interact with AGO1/RISC complex in order to perform RNA cleavage, or translation repression.

58

How do microRNAs work?

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59

Does microRNA172 affect floral development?

Yes, same effect as ap2 mut. No petals or sepals, but extra stamens and carpels.

60

How can you identity if miRNA binds to ap2 mRNA in vivo?

ap2 protein w/ diff RNA sequence but same protein coding sequence. Should not bind miRNA, but recognise ap2 sequence?

61

What is evidence the the ap2 protein levels are controlled via miRNAs?

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62

How do you test the sufficiency of a gene?

Attach coding region to promoter, and transform construct in plant. Examine for homeotic transformation.

63

Are combinations of the A B and C genes sufficient in producing flowers?

A B and C are necessary but not sufficient for flower development.

64

What proteins interact with AP1, AP3, PI and AG? How did they find this out?

SEP3 (SEPELLATA).
yeast two hybrid experiment.

65

What is the revised ABC model in regards to in vitro?

SEP3 interacts with MAD box TF AP1, AP3 an AG.

66

Is SEP3 required in vivo for floral development?

Yes, in combination can make flowers.

67

Describe the reproduction cycle in angiosperms.

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68

Define heterospory.

Heterospory is the production of spores of two different sizes and sexes by the sporophytes of land plants.

69

Describe the generation changes with heterospory.

• Heterospory requires meiotic reduction.
o Sporophyte → meiotic reduction to microspores (male) and megaspores (female).
¥ → allows formation of gametophyte.

70

What is the male and female gametophytes?

Male - microspores.
Female - megaspores.

71

Where does the male gametophyte develop?

Anthers.

72

Describe structure of the anther.

Microsporangium, Tapetum, Locules.

73

Describe microsporogenesis.

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74

Describe microgametogenesis.

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75

Define microsporogenesis.

The formation of microspores inside the microsporangia (or pollen sacs) of seed plants.

76

Define microgametogenesis.

Microgametogenesis is the process in plant reproduction where a microgametophyte develops in a pollen grain to the three-celled stage of its development.

77

Function of microgametophyte?

Formation of pollen tube.

78

Where does the megagametophyte develop?

Ovue.

79

Describe megagametogenesis.

3 mitotic divisions without any cell wall divisions, instead cellularises.
Functional megaspore is selected for in meiosis.

80

Function of megagametophyte?

Pollen tube grows to microplast to release sperm in the ovule. One sperm goes ot egg cell and the other to CZ via high pressure release.

81

Gametogenesis involves several basic cell biological processes, what are they?

Mitosis, Cell Wall Synthesis, and Nuclear Migration.