Q. Identify the correct statements regarding the structure of DNA:

(A). The two chains have anti-parallel polarity 

(B). The backbone is constituted by sugar-phosphate 

(C). Adenine pairs with Thymine through three hydrogen bonds 

(D). The pitch of the helix is 3.4 nm

Choose the correct answer from the options given below:

TLS Online TPP Program

#Question id: 40521

#Environmental Science

ASSERTION–REASON

Assertion (A): Numerical taxonomy uses many observable characters.

Reason (R): It reduces subjectivity in classification.

TLS Online TPP Program

#Question id: 40522

#Environmental Science

ASSERTION–REASON

Assertion (A): Cytotaxonomy helps identify evolutionary relationships.

Reason (R): Chromosome number and structure vary among taxa.

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#Question id: 40523

#Environmental Science

Match the classification approach with its core principle

Column I	Column II
A. Cladistics	1. Shared derived characters
B. Phenetics	2. Overall similarity scoring
C. Evolutionary taxonomy	3. Ancestry + degree of divergence
D. Biosystematics	4. Population-level variation

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#Question id: 40524

#Environmental Science

Match taxonomic evidence with interpretation

Column I	Column II
A. Homologous organs	1. Common ancestry
B. Analogous organs	2. Convergent evolution
C. Vestigial structures	3. Evolutionary remnants
D. Molecular homology	4. Genetic relatedness

TLS Online TPP Program

#Question id: 40525

#Environmental Science

Consider the following statements regarding species delimitation:

1.Reproductive isolation is central to the biological species concept

2.Cryptic species challenge morphology-based taxonomy

3.Allopatric populations are always separate species

4.Molecular evidence can reveal hidden diversity

Which are correct?

TLS Online TPP Program

#Question id: 40526

#Environmental Science

Evaluate statements about systematics data integration:

1.Morphological data may reflect adaptive convergence

2.Molecular data eliminate all classification ambiguity

3.Integrative taxonomy improves reliability

4.Chromosomal variation aids species discrimination