Question

answer all pls

5 Figure K 3 19. Which of the bonds in Figure K above are hydrogen bonds? A. 1 only B. 1&2 C. 2 only D. 3 only E. 4 only 20. What macromolecule is shown in Figure K above? A. A protein B. DNA C. A triglyceride D. A carbohydrate E. RNA Figure M CH3 он NH2 21. How many asymmetric carbons does the molecule in Figure M have? A. 3 B. 2 C.4 D.1 E.O 22. The molecule pictured in Figure M is a(n)? A. Amino acid B. Nucleic acid C. Carbohydrate D. Hydrocarbon E. Triglyceride

Answer 1

19. Option A is correct i.e. 1 only is hydrogen bond.

The two nitrogen bases in a base pair forms Hydrogen bonds. (represented by 1)

The bond between nitrogenous base and Sugar is called Glycosidic bond i.e. the sugar and nitrogen are bonded by beta-N- glycosidic bond.( represented by 2)

The bond between sugar and phosphorus is called Phosphoester bond. ( represented by 3)

The bond between 4th and 5th carbon of glucose molecule is Covalent bond.( represented by 4).

20. Correct option is B. The macromolecule shown is DNA.

As the macromolecule is made up of monomeric units comprising of NUCLEOTIDES containing nitrogenous base, phosphorus and sugar. Also the sugar used is DEOXYRIBOSE as it's 2' -OH is replaced by -H.

21. Correct option is B.

The molecule have 2 asymmetric carbons.

Carbon number 2 and 3 are chiral carbons( asymmetric carbon) as they contain all different groups attached to them.

22. Correct option is A.

The molecule shown in the picture is an AMINO ACID as it contain one carboxylic group, one amino group, one R group containing carbon and one hydrogen all attached to the central carbon numbered 2.

23. Correct option is C.

The two strands of DNA are held by hydrogen base pairing between nitrogen bases of two strands which can easily be broken to serve each strand as a template for enzymes like DNApolymerase for DNA replication and RNA polymerase for transcription.

24. Correct option id E.

DNA replication occurs in one direction only i.e. 5' to 3' of the new strand formed.

the two strands of DNA are anti-parallel to each other and hence in one strand the DNA is replicated easily but the orientation of other strand is opposite i.e. 3' to 5' so smaller fragments are formed which joins later to give complete strand.

25. Option A is correct.

According to Chargaff's rule, in a DNA molecule A is always equals to T and G is always equal to C.

This implies that A+C = G+T.

26. A is the correct answer.

The uptake of DNA or RNA molecule from the environment by bacteria is very common and is called transformation.

The living bacteria took up the genes from the heat killed bacteria and hence show fluorescence now.

27. Correct option is D.

28. E is the correct option.

The movement of chromosomes towards poles in anaphase occurs due o the depolymerization or shortening of the microtubules which when disturbed halts chromosome movement.