Practice Questions

TLS Online TPP Program

#Question id: 3990

Which of the following statements is true of the attenuation mechanism used to regulate the tryptophan biosynthetic operon in E. coli?

#Unit 3. Fundamental Processes

Attenuation is the only mechanism used to regulate the trp operon.
One of the enzymes in the Trp biosynthetic pathway binds to the mRNA and blocks translation when tryptophan levels are high.
The leader peptide plays a direct role in causing RNA polymerase to attenuate transcription.
Trp codons in the leader peptide gene allow the system to respond to tryptophan levels in the cell.

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TLS Online TPP Program

#Question id: 12160

#Unit 9. Diversity of Life Forms

Which of these was not derived from an ancestral alpha proteobacterium?

TLS Online TPP Program

#Question id: 12161

#Unit 8. Inheritance Biology

If a cross is made between two plant heights 46cm and 10cm. The f2 Genotype has been shown;

I) AABBCC - 2) AABBCc – 3) AABbCc – 4) AaBbCc– 5) AaBbcc – 6) Aabbcc – 7) aabbcc –

Find out the

i) phenotypic values of the given character

ii) determining the no of polygenes involves and

iii) what will be the no of QTL?

TLS Online TPP Program

#Question id: 12162

#Unit 8. Inheritance Biology

Nilsson-Ehle’s cross obtained homozygous varieties of wheat that differed in color, he crossed a variety of wheat that possessed white kernels with a variety that possessed red kernels and obtained the following results:

The following conclusions are made from the results obtained;

TLS Online TPP Program

#Question id: 12163

#Unit 8. Inheritance Biology

A cross is made between the two pure line homozygous plant their height is 6cm and 2cm. the F1 progeny shows 6 cm height. the variations takes place in F2 progeny , which were made by

TLS Online TPP Program

#Question id: 12164

#Unit 8. Inheritance Biology

What is the value of broad sense and narrow sense heritability respectively , if the given values of;

A) dominance genetic variance =0.4 ,

B) genic interaction variance =0.3,

C) additive genetic variance =0.6,