Deficiency of which of the following leads to dermatitis,diarrhea,and dementia?

Which of the following is essential for living systems?

Match the items in Column-$I$ with Column-$II$ and select the correct option.

Column-$I$	Column-$II$
$(A)$ Aspartic acid	$(i)$ Two $\alpha$-chains and two $\beta$-chains
$(B)$ Haemoglobin	$(ii)$ $FMN$
$(C)$ Cytoplasm	$(iii)$ Nitrogen fixation
$(D)$ Azotobacter	$(iv)$ Site of protein synthesis
	$(v)$ Polar and negatively charged amino acid

Which type of bond connects the hydrogen and oxygen atoms within a water molecule?

Select the correct option for the following matches:

$(1)$ Carbohydrate	$(a)$ Ester bond
$(2)$ Lipid	$(b)$ Glycosidic bond
$(3)$ Protein	$(c)$ Phosphodiester bond
$(4)$ Nucleic acid	$(d)$ Peptide bond

Which of the following statements are correct?
$(a)$ Proteins are heteropolymers of amino acids.
$(b)$ The sugar found in nucleic acids is of the $\beta$-type.
$(c)$ Nucleic acids exhibit acidic properties.
$(d)$ $5$-methyl uracil is attached to the first carbon atom of the ribose sugar.
$(e)$ Collagen is the most abundant protein found in the plant kingdom.