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Flashcards in Module 5 EXAM PRACTICE Deck (105):
1

High concentration of which which protein stimulates the development of anterior structures?

Bicoid

2

Conserved developmental genes can lead to _______ evolution.

parallel

3

The correct sequence in which Drosophila body axis genes act is:

egg-polarity genes--->gap genes --->pair-rule genes---->segment polarity genes--->homeotic genes.

4

Pair-rule genes loss-of-function mutation phenotype

Deletes every other segment

5

Gap genes loss-of-function mutation phenotype

Delete adjacent segments

6

Segment-polarity genes loss-of-function mutation phenotype

Affect polarity of segment; part of segment is replaced by mirror image of part of another segment.

7

Genes that regulate development are conserved. This means that they

have changed very little over the course of evolution.

8

When the mammalian Pax6 gene is overexpressed in flies,

flylike eyes develop.

9

The following are NOT characteristics of maternal effect mutations:

When mutant offspring arise they account for 50% of the offspring.

Mutant offspring arise from homozygous mutant fathers crossed to heterozygous mutant mothers.

Wild-type offspring arise from crosses of heterozygous mutant fathers regardless of the genotype of the mother.

Heterozygous mutant fathers crossed to homozygous normal mothers will not produce normal offspring.

10

The following are characteristics of maternal effect mutations:

Mutant offspring arise from homozygous mutant mothers irrespective of the genotypes of the father

11

Deletion of the _______ gene in Drosophila converts the 3rd thoracic segment into the second thoracic segment, resulting in a fly with 2 sets of fully formed wings.

Ubx

12

The expression of a zygotic gene product is based on the ____________________.

genotype of the zygote

13

TRUE or FALSE?

In Drosophila homeotic genes are present in 2 gene complexes.

True

14

A self-contained unit that is made up of other units is called a

module

15

Establishment of the dorsal-ventral axis of the Drosophila embryo:

Involves the nuclear localization of Dorsal protein in the ventral nuclei.

16

Many of the genes that control development encode _______ that act on proteins in a cascade of events.

transcription factors

17

Which of the following statements is true?

1. The transcription factors and the extracellular signals that govern pattern formation can be thought of as the molecular “black box.”

2. Developmental processes in both Drosophila and vertebrates are controlled by similar sets of genes.

3. Many regulatory genes are required to bring about the diversity of organisms that we observe.

Developmental processes in both Drosophila and vertebrates are controlled by similar sets of genes.

18

TRUE or FALSE?

The human Hox genes are similar in sequence to the homeotic genes found in Drosophila, but are not lined up in the the same order.

FALSE

19

The ability of an organism to modify its development in response to environmental conditions is called

developmental plasticity.

20

Which of the following is NOT a way plants differ from animals regarding regulatory genes that affect their development?

a) Plants have tremendous developmental plasticity.

b) Plant cells do not have MADS box genes and homeobox genes.

c) Future reproductive cells are not set aside during early plant development.

d) None of the above

e) Plant cells do not move relative to one another.

Plant cells do not have MADS box genes and homeobox genes.

21

Which scientist performed experiments with eyeless and Pax6?

Rebecca Quiring

22

The transcription factors that govern pattern formation in multicellular organisms, and the genes that encode them, are components of what biologists call the molecular _______.

tool kit

23

Ways that plants differ from animals regarding regulatory genes that affect plant development:

Plants have tremendous developmental plasticity.

Future reproductive cells are not set aside during early plant development.

Plant cells do not move relative to one another.

24

What is true of homeotic transformations in Drosophila?

they can be passed on from generation to generation

25

The action of genes controlled by _______ determines where and when they will be expressed or suppressed.

genetic switches

26

Which of the following is NOT a developmental environmental signal?

a) Temperature
b) Light
c) The presence of predators
d) All of the above are developmental environmental signals.

All of the above ARE developmental environmental signals.

27

List some developmental environmental signals

Temperature
Light
The presence of predators

28

What are the role and relationship of egg-polarity genes, segmentation genes, pair-rule genes, gap genes, and homeotic genes in Drosophila development?

??
EXTENDED RESPONSE


Egg polarity genes establish the anterior-posterior axis of the embryo using a concentration gradient of maternal mRNAs and proteins.
This gradient activates the gap genes, which divide the embryo into broad bands of head/thorax/abdomen.
Gap gene products activate pair-rule genes, which divide embryo into segments.
Pair-rule genes activate segment polarity genes in each segment, dividing each into anterior and posterior regions and aligned linearly.
Homeotic genes will determine the identity of each segment by determining which adult structure will be formed by the segment.

29

Flies have _______ eyes, while mammals have _______ eyes.

Flies have compound eyes, while mammals have _______ eyes.

30

dorsal

nuclear localization

31

bicoid and nanos

??!
c, anterior–posterior axis

32

Bicoid (bcd) is a maternal effect gene required for anterior development in fruit flies. Suppose that a egg from a mutant mother is destined to develop into an embryo with two posterior ends. A scientist does an experiment with this embryo.


The scientist injects wild type bicoid mRNA at the location that in a wildtype would have formed the posterior end of a developing embryo. What will be the phenotype of the injected larva? Justify your answer.

Certified Correct:

(i) The injected DNA will have no effect since bicoid is a maternal effect gene. Thus, the insertion of DNA into the embryo will have no effect. The larva will still develop two posterior ends.

(ii) The injected mRNA will cause the larva to develop normally (1 posterior end and 1 anterior end). It will compensate for the lack of functional bicoid mRNA from the mother.

33

Morphogens control cell fate at ____________ concentrations.

??!!

3 or more

34

Which of the following statements is false?


a) All of the above are true.

b) Homologous genes encoding similar transcription factors are expressed in similar patterns along the anterior–posterior axes of both mammals and insects.

c) Ubx is a Hox gene.

d) The full-sized wing in Drosophila is normally produced on just the third thoracic segment.

e) Deletions of the Ubx gene convert the 3rd thoracic segment into the 2nd thoracic segment.

The full-sized wing in Drosophila is normally produced on just the 3rd thoracic segment.

35

The developmental pathway for sex determination in Drosophilia is best exemplified by which of the following statements:

One developmental state is the default, whereas its alternative requires the activation of a series of regulatory gene products.

One developmental state is the default, whereas its alternative requires the activation of a series of regulatory gene products.

Regulation occurs at more than one level from the gene to the active protein.

An on-off decision for a master switch is made early on in development.

All of the above are true.

36

What are some of the different signals that can initiate programmed cell death (apoptosis)?

??!!!
EXTENDED RESPONSE

Infection by Virus, DNA damage, damage to the mitochodria

37

Drosophila passes through ______ larval stages and a ____before developing into an adult fly.

??

3, pupa stage

38

There are ______ Hox gene cluster in mammals

4

39

Mutations in homeotic genes often cause

structures to appear in the wrong place

40

_______ is the ability to express different phenotypes under different environmental conditions.

Developmental plasticity

41

Master regulatory genes are ___________ and ____________ to determine cell fate.

??!!!

"necessary, sufficient"

42

ontogeny recapitulates phylogeny

j, Ernst Haeckel

43

In wild-type flowering plants, carpel development is determined by what class of gene products?

C gene products

44

Which of the following statements is false?


a) The cameralike eyes of mammals are composed of thousands of individual lenses known as ommatidia.

b) eyeless/Pax 6 acts as a molecular switch.

c) Evolutionary developmental biology is often called “evo-devo.”

d) All of the above are true.

e) Eyes evolved many times independently within the animal kingdom.

The cameralike eyes of mammals are composed of thousands of individual lenses known as ommatidia.

45

The _______ thoracic segment of Drosophila bears small hind wings that function as _______ organs.

third; balance

46

Insects have _______ legs.

6

47

The nanos mRNA is localized at the ________ end of the Drosophila egg.

posterior

48

TRUE or FALSE?

The function of the gene dorsal is required for determining the left/right axis during Drosophila development.

False

49

What is the role of maternal-effect genes?

Certified Correct:

Genes derived from the maternal genome are actively transcribed to support the zygote and are required for the proper patterning of the embryo.
Mutant phenotypes of maternal-effect reflect the genotype of the mother.

50

Genetic switches are involved in....

helping various modules develop differently.

51

Egg-polarity genes regulate __ genes, which in turn modulate the activity of __ genes.

??!!!

"gap, pair-rule"

52

The bicoid mRNA is localized at the ________ end of the Drosophila egg.

anterior

53

_______ allows morphological changes to occur without disrupting the entire organism.

Modularity

54

The expression of a maternal gene product is based on the _____________________________.

??
genotype of the mother

55

Match the Drosophila developmental stages with the gene families regulating the development of these stages.

Egg-polarity genes

Establishment of main body axis

56

Match the Drosophila developmental stages with the gene families regulating the development of these stages.

Homeotic genes

Establishment of identity of each segment

57

Match the Drosophila developmental stages with the gene families regulating the development of these stages.

Segmentation genes

Determination of the number of body segments

58

Which of the statements below are true about the pattern of gap gene expression in early Drosophila development?

1. It is determined by the activity of the anterior-posterior morphogens BCD and HB-M.

2. It contributes to dorsal-ventral patterning of the embryo.

3. It determines the pattern of expression of the homeotic genes.

4. it can overlap with the expression domain of another gap gene

5. It is dependent upon previous expression of the segment polarity genes.

6. It determines the pattern of expression of the pair-rule genes.

It is determined by the activity of the anterior-posterior morphogens BCD and HB-M.

It determines the pattern of expression of the homeotic genes.

It can overlapp with the expression domain of another gap gene

It determines the pattern of expression of the pair-rule genes.

59

Developmental plasticity is...

the ability to express different genotypes under different environmental conditions.

60

Most regulatory genes have evolved little over a period of millions of years; therefore, they are said to be _______.

conserved

61

antennapedia complex

h, homeotic gene

62

Which of the following about Ubx is true?

a) It turns on the genes that promote the function of the veins and other structures of the forewing.

b) It binds to cells of the third thoracic segment in butterflies.

c) None of the above

d) All of the above

e) In Drosophila, it is expressed by cells that form the hindwings.

In Drosophila, it is expressed by cells that form the hindwings.

63

What are morphogens and what do they do?

??
EXTENDED RESPONSE

Morphogens are master regulators that determine embryo fates at 3 or more concentrations.
They signal certain parts of the cell telling that part of the embryo what it will turn into.
BCD and HB-M are examples

Formation of concentration gradients of diffusible developmental regulatory molecules (morphogens) establishes positional information in developmental fields.

64

The homeotic, gap, pair-rule, and segment polarity genes ALL control:

the number of segments.

65

pair-rule genes

i, segmentation gene

66

The ability of organisms to modify their development (and hence, their phenotype) in response to environmental stimuli is known as developmental _______.

i, segmentation gene

67

Components of DNA, called _______ control how the molecular toolkit is used.

genetic switches

68

How do developmental genes constrain evolution?

a) Modifying previously existing structures

b) Maintaining highly conserved genes

c) Creating novel structures

d) Both a and b

e) All of the above

Both a and b:

Modifying previously existing structures
AND
Maintaining highly conserved genes

69

Which of the following statements about the gene eyeless is true?

a) None of the above

b) It encodes a transcription factor.

c) It is found in Drosophila.

d) All of the above

e) Pax6 is the equivalent gene in mice.

All of the above

70

To study mammalian segmentation in the mouse, zygotically acting mutations are generated. A recessive mutation is identified. It causes all seven cervical vertebrae to be missing. Given the striking evolutionary conservation of many aspects of development in mice and flies, one way to determine which gene is mutated is to look for a gene affecting an analogous process in Drosophila.

What type of segmentation gene in Drosophila is most analogous to the loss of seven cervical vertebrae produced by the recessive mouse mutation?

Gap gene

71

TRUE or FALSE?

Segmentation genes determine the identity of individual segments during development.

False

72

egg-polarity genes

??!!!

c, anterior–posterior axis

73

TRUE or FALSE?

Many plant cells remain totipotent throughout development.

True

74

What are Hox genes?

??
EXTENDED RESPONSE

Hox genes are homeotic genes that are expressed in a particular pattern along the Anterior-Posterior axis of many animals, including humans and Drosophila.

Hox genes code for transcription factors that are involved in the production of segment-specific structures.

The arrangement of Hox genes on a fruit fly chromosome correspond with expression of Hox genes in different body segments of a fruit fly embryo.

75

The maternal-effect Bicoid gene codes for ________________

a DNA-binding transcription factor

76

Alterations in the spatial expression patterns of regulatory genes can result in

evolutionary change.

77

TRUE or FALSE?

A morphogen is a protein that can restore totipotency to cells from an adult animal.

False

78

TRUE or FALSE?

Plant cells can not be cloned from single isolated cells.

False

PLANTS CAN BE CLONED

79

Which of the following statements is true?

a) Adults are made up of modules.

b) Many developmental genes exert their effects on only a single module.

c) Embryos are made up of modules.

d) All of above

e) None of the above

All of above

80

TRUE or FALSE?

Homeotic genes in mammals are dissimilar to those in Drosophila

False

81

_______ is a shift in the relative timing of two different developmental processes that can result in new morphology.

Heterochrony

82

Which of the following is true of homeotic transformations in Drosophila?


they can be passed on from generation to generation

they are not amenable to genetic analysis

they are caused by genes that are not conserved across species

they are always caused by more than one mutation in these genes

none of the above

they can be passed on from generation to generation

83

When the mammalian Pax6 gene is overexpressed in flies,

flylike eyes develop.

84

_______ allows morphological changes to occur without disrupting the entire organism.

Modularity

85

Which of the following statements is false?

a) The cameralike eyes of mammals are composed of thousands of individual lenses known as ommatidia.

b) All of the above are true.

c) Eyes evolved many times independently within the animal kingdom.

d) Evolutionary developmental biology is often called “evo-devo.”

e) eyeless/Pax 6 acts as a molecular switch.

The cameralike eyes of mammals are composed of thousands of individual lenses known as ommatidia.

86

What are homeotic genes and what do they do?

??
EXTENDED RESPONSE

Homeotic genes code for transcription factors that control the development of segment-specific body parts.

This class of genes controls the developmental identity of segments along the anterior-posterior axis.

Homeotic genes are regulatory genes that work after the body axes have been established.

Homeotic genes identify particular body segments in an individual, eventually leading to the formation of segment-specific body structures in the correct locations on the body.

87

_______ is the ability to express different phenotypes under different environmental conditions.

Developmental plasticity

88

Components of DNA, called _______ control how the molecular toolkit is used.

genetic switches

89

Master regulatory genes are ___________ and ____________ to determine cell fate.

necessary and sufficent

90

Genes that regulate development are conserved. This means that they

have changed very little over the course of evolution.

91

Many of the genes that control development encode _______ that act on proteins in a cascade of events.

transcription factors

92

Bicoid (bcd) is a maternal effect gene required for anterior development in fruit flies. Suppose that a egg from a mutant mother is destined to develop into an embryo with two posterior ends. A scientist does an experiment with this embryo.


The scientist injects wild type bicoid mRNA at the location that in a wildtype would have formed the posterior end of a developing embryo. What will be the phenotype of the injected larva? Justify your answer.

Certified Correct:

(i) The injected DNA will have no effect since bicoid is a maternal effect gene. Thus, the insertion of DNA into the embryo will have no effect. The larva will still develop two posterior ends.

(ii) The injected mRNA will cause the larva to develop normally (1 posterior end and 1 anterior end). It will compensate for the lack of functional bicoid mRNA from the mother.

93

pair-rule genes

i. segmentation gene

94

The developmental pathway for sex determination in Drosophilia is best exemplified by which of the following statements:

One developmental state is the default, whereas its alternative requires the activation of a series of regulatory gene products.

One developmental state is the default, whereas its alternative requires the activation of a series of regulatory gene products.

Regulation occurs at more than one level from the gene to the active protein.

An on-off decision for a master switch is made early on in development.

All of the above are true.

All of the above are true.

95

Mutations in homeotic genes often cause

structures to appear in the wrong place

96

Morphogens control cell fate at ____________________ concentrations.

??

3 or more concentrations.

97

i. segmentation gene

i. pair-rule gene

98

antennapedia complex

h. homeotic gene

99

j. ontogeny recapitulates phylogeny

j. Ernst Haeckel

100

dorsal

b. nuclear localization

101

egg polarity

c. anterior–posterior axis

102

bicoid and nanos

c. anterior–posterior axis

103

In Drosophila homeotic genes are present in two gene complexes

true

104

A morphogen is a protein that CANNOT restore totipotency to cells from an adult animal.

....

105

if maternal-effect:
-and mother is heteroz. wild type/mutant, then progeny will all be wild type...NO MATTER WHAT THE FATHER GENOTYPE IS

-and if mother is homozygous mutant, then progeny will all be mutant ...NO MATTER WHAT THE FATHER GENOTYPE IS

if zygotic:
just treat like normal monohybrid cross.


m/+ is wildtype and mm is mutant right?
+ is wildtype and m is mutant. in this scenario m is recessive and + is dominant so yes, what you said is correct