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#Question id: 12349


Males in a population differ in the time they spend displaying to females. A researcher hypothesizes that predators are responsible for these differences. Males display for longer durations when there are no predators in the vicinity and for shorter durations when there is a predator nearby. Which of the following study designs is the most appropriate test of this hypothesis?

#Unit 10. Ecological Principles
  1. Map predator distribution in the area; measure the abundance of females; quantify the natural variation in male display rates in areas without predators
  2. Measure display  rates of  males at  the beginning  of  the breeding season; remove all  predators from the study site; then measure male display rates later in the breeding season; repeat for multiple populations
  3. Measure display rates of males in areas with and without predators; randomly assign males to two treatments: (i) capture and release back in original area (ii) capture and switch between areas; measure display rates for all experimental males
  4. Measure display rates of males in areas with and without predators; randomly assign males to two treatments: (i) addition of females to the area (ii) removal of females from the area; measure display rates for all experimental males
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TLS Online TPP Program

#Question id: 5296

#Unit 8. Inheritance Biology

A transformation experiment is performed with a donor strain that is resistant to four drugs: A, B, C, and D. The recipient is sensitive to all four drugs. The treated recipient cell population is divided up and plated on media containing various combinations of the drugs. The table below shows the results. What is the probable order of the three tightly linked genes?  

TLS Online TPP Program

#Question id: 5295

#Unit 8. Inheritance Biology

A cross is made between an Hfr that is met+ thi+ pur+ and an F-that is met- thi- pur-. Interrupted mating studies show that met+ enters the recipient last, so met+ recombinants are selected on a medium containing supplements that satisfy only the pur and thi requirements.  These recombinants are tested for the presence of the thi+ and pur+ alleles. The following numbers of individuals are found for each genotype:

A) Gene Order

I

Thi Pur  Met

II

Pur  Met  Thi

III

Pur   Thi  Met

B) Distance between Pur and Thi

IV

15.4 map unit

V

1.8 map unit

What is the following correct combination?

TLS Online TPP Program

#Question id: 5294

#Unit 8. Inheritance Biology

Interrupted mating experiments were performed using three different Hfr strains (1-3). The three strains have different combinations of selectable markers. The time of entry for markers for each strain is shown is shown in the table given.

Hfr 1

Phe

(5)

Trp

(35)

Met

(50)

Ala

(52)

Hfr 2

Trp

(2)

Val

(12)

His

(57)

Pro

(87)

Hfr 3

Ala

(10)

Met

(12)

Val

(37)

Phe

(57)

Using the above data, predict the correct sequence of markers on the E. coli chromosome

TLS Online TPP Program

#Question id: 5293

#Unit 8. Inheritance Biology

The two strains a and b are tested for being auxotrophic for the following nutritional mutations: pyridoxine (pdx), biotin (bio), methionine (met), adenine (ade), and para-aminobenzoic acid (pab). Growth is indicated by ( + ) and lack of growth by ( - ). From these tests, what is genotype of strain a and b respectively (+ indicate prototroph while other auxotroph)? 

TLS Online TPP Program

#Question id: 5292

#Unit 8. Inheritance Biology

A transformation experiment is performed with a donor strain that is resistant to four drugs: W, X, Y, and Z. The recipient is sensitive to all four drugs. The treated recipient population is divided up and plated on media containing various combinations of the drugs. The table below shows the results:

Drug(s) added

Number of Colonies

None

20,000

WX

76

WY

1324

WZ

1976

XY

85

XZ

69

YZ

1564

WXY

50

WXZ

62

WYZ

1354

XYZ

48

WXYZ

53

Following observation are given

A) X gene is obviously quite distant from the other three genes

B) Y gene is obviously quite distant from the other three genes

C) The Order is three closely link gene W Z Y

D) The Order is three closely link gene W X Z

Which of the following combination is correct?

TLS Online TPP Program

#Question id: 5291

#Unit 8. Inheritance Biology

A number of nutritional mutant strains were isolated from wild-type Neurospora that responded to the addition of certain supplements in the culture medium by growth ( + ) or lack of growth ( -). Given the following responses for single gene mutations, diagram a metabolic pathway that could exist in the wild-type strain that is most consistent with the data. Indicate where the pathway is blocked in each mutant strain.