An organism has the following architectural pattern:
(i). Multicellular with germ layers
(ii). A coelom derived from the mesoderm
(iii) Primary bilateral symmetry with secondary radial symmetry
(iv) Presence of endo‐skeletal plates

Such an organism is most likely to
A. Have mesohymal as its connective tissue
B. Undergo torsion, whereby the mouth and anus are properly oriented
C. Be devoid of a brain but have calcareous spicules
D. Have comb plates to help in locomotion

Which of the following is true?

• A and C

• C only

• D only

• B and C

Industrial products in which bacteria are employed for production are shown in the following table:

I. List of product	II. Microorganism
A. 2,3- Butane diol	i) Leuconostoc
B. Dextran	ii) Brevibacterium
C. Glutamic acid	iii) Bacillus polymxa
D. Cobalamine	iv) Propionibacterium

The correct combinations are:

• A – iii; B – i; C – ii; D – iv

• A – i; B – ii; C – iii; D – iv

• A – iii; B – ii; C – iv; D – i

• A – ii; B – iii; C – iv; D – i

13.

In contrast with plant cells, the most distinctive feature of cell division in animal cells is

• Control of cell cycle transitions by protein kinases.  

• Enzymes responsible for DNA replication.  

• Ubiquitin-dependent pathway for protein degradation

• Pattern of chromosome movement.  

Most common type of phospholipids in the cell membrane of nerve cells is

• Phosphatidylcholine 

• Phosphatidylinositol 

• Phosphatidylserine 

• Sphingomyelin

The membrane lipid molecules assemble spontaneously into bilayers when placed in water and form a closed spherical structure known as

• Lysosome

• Peroxisome

• Liposome

• Endosome

In gene regulation, Open Reading Frame (ORF) implies

• Intervening nucleotide sequence in between two genes.  

• A series of triplet codons not interrupted by a stop codon.

• A series of triplet codons that begins with a start codon and ends with a stop codon.  

• The exonic sequence of a gene that corresponds to the 5’UTR of the mRNA and thus does not code for the protein

A nerve impulse or action potential is generated from transient changes in the permeability of the axon membrane to Na⁺ and K⁺ ions. The depolarization of the membrane beyond the threshold level leads to Na⁺ flowing into the cell and a change in membrane potential to a positive value. The K⁺ channel then opens allowing K⁺ to flow outwards ultimately restoring membrane potential to the resting value. The Na⁺ and K⁺ channels operate in opposite directions because

• There is an electrochemical gradient growth generated by proton transport  

• There is difference in Na⁺ and K⁺ concentrations on either side of the membrane  

• Na⁺ is a voltage-gated channel, whereas K⁺ is ligand-gated   

• Na⁺ is dependent on ATP whereas K⁺ is not   

The erythrocytes membrane cytoskeleton consists of a meshwork of proteins underlying the membrane. The principal component spectrin has α, β subunits which assemble to form tetramers. The cytoskeleton is anchored to the membrane through linkage with the transmembrane proteins band 3 and glycoprotein C. The cytosolic domain of band 3 also serves as the binding site of glycolytic enzymes such as glyceraldehydes 3-phosphate dehydrogenase. Analysis of blood sample of a patient with haemolytic anemia shows spherical red blood cells. The patient carries

• A mutation in glycophorin C

• A mutant spectrin with increases tetramerization propensity  

• Mutant β spectrin defective in αβ dimerization ability   

• Mutant glyceraldehydes 3-phosphate dehydrogenase

In cellular respiration, which of the following processes occur only inside mitochondria and not in the cytoplasm?

• Glycolysis and the pentose-phosphate pathway

• Glycolysis and the citric acid cycle

• The citric acid cycle and oxidative phosphorylation

• Glycolysis and oxidation phosphorylation

Acetylcholine receptor is an archetype for:

• Ligand-gated ion channel

• ATPase dependent voltage-gated ion channel

• ATPase dependent Ca²⁺ gated ion channel

• ATPase independent voltage gated ion channel.