The stage during which separation of the paired homologous chromosomes begins is

• Pachytene

• Diplotene

• Zygotene

• Diakinesis

The two functional groups characteristic of sugars are

• Hydroxyl and methyl

• Carbonyl and methyl

• Carbonyl and hydroxyl

• Carbonyl and phosphate

Which of these statements is incorrect?

• Enzymes of TCA cycle are present in mitochondrial matrix

• Glycolysis occurs in cytosol

• Oxidative phosphorylation takes place in outer mitochondrial membrane

• Glycolysis operates as long as it is supplied with NAD that can pick up hydrogen atoms

Use of bioresources by multinational companies and organisations without authorisation from the concerned country and its people is called

• Bio-infringement

• Biopiracy

• Bioexploitation

• Biodegradation

Which of the following is commonly used as a vector for introducing a DNA fragment in human lymphocytes?

• Retrovirus

• Ti plasmid

• pBR 322

• λ phage

Double fertilization is

• Fusion of two male gametes of a pollen tube with two different eggs

• Fusion of one male gamete with two polar nuclei

• Syngamy and triple fusion

• Fusion of two male gametes with one egg

Which among the following is not a prokaryote?

• Saccharomyces

• Mycobacterium

• Oscillatoria

• Nostoc

Pollen grains can be stored for several years in liquid nitrogen having a temperature of

• –120°C

• –80°C

• –160°C

• –196°C

Many ribosomes may associate with a single mRNA to form multiple copies of a polypeptide simultaneously. Such strings of ribosomes are termed as

• Polysome

• Polyhedral bodies

• Nucleosome

• Plastidome

Which of the following is true for nucleolus?

• Larger nucleoli are present in dividing cells

• It is a membrane-bound structure

• It is a site for active ribosomal RNA synthesis

• It takes part in spindle formation