During muscle contraction

• size of 'A' bands remain same

• size of 'H' zone becomes smaller

• size of 'I' band decreases

• diameter of fibre increases

The plant undergoes wilting when

• xylem is blocked

• cambium is blocked

• phloem is blocked

• some roots are reduced in number

The most advanced type of inflorescence is

• corymb

• catkin

• spadix

• capitulum

The organism in which Kreb's cycle does not occur in mitochondria is

• yeast

• E.coli

• Ulothrix

• mould

Lucocytes (WBCs) are considered as true cells because

• they possess nucleus

• they do not contain haemoglobin

• they show great power of movement

• they are responsible forphagocytic activity

Cranium is made up of

• 8 bones

• 12 bones

• 10 bones

• 16 bones

Stomata open at night and closes during day in

• xerophytes

• gametophytes

• mesophytes

• mesophytes

carthamus tinctorius belongs to family

• Asteraceae

• Solanaceae

• Malvaceae

• Fabaceae

The function of surfactant is/are

• facilitating lung expansion

• maintaining the stable size of the alveoli

•  to reduce the surface tension on the alveoli

• all of the above

Two chief functions of the leaves are

• photosynthesis and respiration

• photosynthesis and transpiration

• transpiration and respiration

• respiration and digestion