Round 2: Biology Portion (Grade 11 PM students)

Cells without nucleoli die because they do not possess

• mitochondria and are unable to obtain energy

• centriole and are unable to undergo cell division

• ribosomes and are unable to manufacture proteins

• lysosomes are unable to destroy worn out organelles

Which one of the following is the major advantage of using a light microscope instead of an electron microscope?

• Constant depth of focus

• Use of very thin section

• Superior resolving power

• Observation of living things

9+2 pattern refers to the configuration of

• microtubule in cilia and flagella

• microfilament in cilia and flagella

• microfilaments in cilia and centriole

• microtubules in centrioles and spindle fibers

Penicillin restricts bacterial growth within the body of an infected person by inhibiting the formation of

• Cell wall

• Cytoplasm

• Cell membrane

• Adenosine triphosphate

1.      ‘Moist heat causes coagulation of proteins and kills microbes.’

The above statement highlights the mode of action of

• A disinfectant

• An antiseptic

• An antibiotic

• A sterilizer

A bacterium is infected with an experimentally constructed bacteriophage composed of the T2 phage protein coat and T4 phage DNA. The new phages produced would have

• T2 protein and T4 DNA

• T2 protein and T2 DNA

• T4 protein and T4 DNA

• T4 protein and T2 DNA

Which of the following pairs of base sequences could form a short stretch of a normal double helix of DNA

• 5′-AGCT-3′ with 5′-TCGA-3’

• 5′-GCGC-3′ with 5′-TATA-3′

• 5′-ATGC-3′ with 5′-GCAT-3′

• All of these pairs are correct

According to the Fluid Mosaic Model of cell membrane, proteins of the membrane are mostly

• embedded in a lipid bilayer

• confined to the hydrophobic interior of the membrane

• randomly oriented in the membrane, with no fixed inside outside polarity

• Spread in a continuous layer over the inner and outer surfaces of the membrane

———— are the non-essential parts of a flower

• Androecium and gynoecium

• Sepals and carpels

• Sepals and petals

• Sepals and gynoecium

Haemoglobin has

• Primary structure

• Secondary structure

• Tertiary structure

• Quaternary structure