In areas of permafrost, stands of black spruce are frequently observed in the landscape, while other tree species are noticeably absent. Often these stands are referred to as "drunken forests" because many of the black spruce often "lean over" (that is, they are displaced from their normal vertical alignment). What is the most likely explanation for the unusual growth of these forests in this marginal habitat?

TLS Online TPP Program

#Question id: 27070

#Unit 1. Molecules and their Interaction Relevant to Biology

Which of the following statements is correct regarding the stereochemistry of Thr, Ile 

1. Thr, Ile is special case because of two chiral center exist in L-Ile in 2R,3S and L-Thr in 2R,3S configuration 

2. Thr, Ile is special case because of two chiral center exist in D-Ile in 2R,3S and D-Thr in 2R,3S configuration 

3. Thr, Ile is special case because of two chiral center exist in L–Ile in 2S,3R and L–Thr in 2S,3R 

4. Thr, Ile is special case because of two chiral center exist in D–Ile in 2S,3R and D–Thr in 2S,3R

TLS Online TPP Program

#Question id: 27069

#Unit 1. Molecules and their Interaction Relevant to Biology

Choose the correct option regarding the stereochemistry of given compound 

TLS Online TPP Program

#Question id: 27068

#Unit 1. Molecules and their Interaction Relevant to Biology

Isoleucine and Threonine have two chiral carbons so exists in multiple RS configuration, choose the correct option regarding the given fig.

1. a is D-threonine is (2S, 3S) threonine

2. b is L-threonine is (2R,3S) threonine

3. a is L-threonine is (2S, 3R) threonine

4. b is D-threonine is (2R,3S) threonine

TLS Online TPP Program

#Question id: 27067

#Unit 1. Molecules and their Interaction Relevant to Biology

Choose the correct statement regarding the stereochemistry of amino acid

1. 16 amino acid except (Thr, Ile, Cys, Gly) L Fischer projection is equal to S and D is equal to R configuration 

2. Thr, Ile is special case because of two chiral center exist in L – Ile/Thr – 2S,3R and D-Ile/Thr–2R,3S configuration  

3. Cys exiest in L- Cys – R & D- Cys – S configuration 

4. Gly is optically inactive 

TLS Online TPP Program

#Question id: 744

#Unit 1. Molecules and their Interaction Relevant to Biology

In a DNA molecule, deoxyribonucleotides are joined into a polymer by the covalent linkage of a phosphate group. The covalent link termed as:

TLS Online TPP Program

#Question id: 745

#Unit 1. Molecules and their Interaction Relevant to Biology

The structure of RNA differs from that of DNA, as RNA contains: