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#Question id: 13142

The Norway rat (Rattus Norvegicus), a widespread pest, was controlled for about a decade by the anticoagulant warfarin. This chemical substance, placed in food pellets, is absorbed by the intestinal tract and inhibits the clotting of blood. After a population decline for about 10 years, rat populations increased and stabilized. In one European population, as illustrated in the graph below, the percentage of rats resistant to warfarin has remained fairly stable over a number of years.

Resistance to warfarin is governed by a dominant autosomal gene, R. More than 15 percent of the resistant animals are heterozygous at this locus (Rr). The table below indicates the response to warfarin and relative reproductive fitness of individuals that are homozygous or heterozygous for the dominant gene (R). The RR individuals have a 20-fold increase in vitamin K requirement over individuals.

Fitness is a measure of the reproductive success of a particular genotype. The highest fitness is 1.00.
There is a substantial number of heterozygotes in the population. Which of the following is the best explanation of this observation?

#Unit 10. Ecological Principles
  1. Heterozygotes (Rr) have a selective advantage over both homozygotes (RR and rr). 
  2. The gene for susceptibility (r) is increasing rapidly each generation.
  3. The gene for susceptibility (r) is being lost by chance each generation.
  4. Dominant homozygotes (RR) enjoy a reproductive advantage over heterozygotes
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#Question id: 7300

#Unit 5. Developmental Biology

Following genes regulate flowering, column I represents genes, column II represents transcription factor family and column III represents functions.

Column I

Column II

Column III

A. FLOWERING D (FD)

i. bZIP

a. Activates flowering

downstream of florigen

B. SUPPRESSOR OF

OVEREXPRESSION OF

CONSTANS1 (SOC1)

ii. MADS

b. Receptor for florigen

C. FLOWERING LOCUS C

 

c. Class E homeotic genes

D. SEPALLATA (SEP)

 

d. Floral repressor

 Which of the following is correct?
TLS Online TPP Program

#Question id: 22944

#Unit 5. Developmental Biology

In the floral meristem, the FT-FD complex activates the expression of
TLS Online TPP Program

#Question id: 22938

#Unit 5. Developmental Biology

Genes that regulate flowering, have different transcription factors and functions:
 
Choose correct match:
TLS Online TPP Program

#Question id: 7314

#Unit 5. Developmental Biology

With reference to plant flowering pattern; match the terms of Column I with the most appropriate term of Column II. (Se-Sepal; Ca-Carpel; St-stamen; Pe-Petal)

s.no.

Homeotic mutants

(Column 1)

S. No

Flower patterning

(Column 2)

A.     

Apetala2 mutant

                    I.  

Ca-Ca-Ca-Ca

B.      

Agamous /Apetala3 mutant

                    II.    

Se-Pe-Pe-Se

C.      

Agamous mutant

               III. 

Se-Se-Se-Se

D.     

Apetala2/Apetala3 mutant

                IV.

Ca-St-St-Ca

 
TLS Online TPP Program

#Question id: 7312

#Unit 5. Developmental Biology

Following statements regarding to the classes of genes that regulate floral development:

A.  Floral organ identity genes directly control floral identity. The proteins encoded by these genes are transcription factors that likely control the expression of other genes whose products are involved in the formation and/or function of floral organs.

B.  Cadastral genes act as spatial regulators of the floral organ identity genes by setting boundaries for their expression.

C.   Meristem identity genes are necessary for the initial induction of the organ identity genes. These genes are the positive regulators of floral organ identity.

D.  Cadastral genes act as negative regulators of the floral organ identity genes by inhibits their expression.

E.   Meristem identity genes are the negative regulators of floral organ identity genes.

Which of the above statements are true?
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#Question id: 7311

#Unit 5. Developmental Biology

According to the ABC model of flower development in Arabidopsis, three classes of organ identity genes— designated A, B, and C— are required to specify the identity of floral organs in each whorl of a flower. If wild type Arabidopsis were transformed with a chimeric gene composed of a C class promoter fused to a B class coding sequence, which of the following arrangements   (outer to inner) would be predicted?