Structural Organisation in Animals — BIOLOGY STD 11 Science — Question

Give the value of CO₂ concentration at which saturation of the rate of photosynthesis occurs in:
(a) C₃ plants and (b) C₄ plants, respectively.

In which phase is DNA replication and chromosome doubling occurs?

Birds have no teeth, then how do they grind the grains they eat as food?

Which two hormones are synthesised by the follicular cells of the thyroid?

Give an example of pinnately compound leaves.

Which one of the plant growth regulators would you use if you are asked to: (a) induce rooting in a twig (b) quickly ripen a fruit (c) delay leaf senescence (d) induce growth in axillary buds (e) 'bolt' a rosette plant (f) induce immediate stomatal closure in leaves.

Name the type of joint between the following :
carpal/metacarpal of thumb

What comes under the plant kingdom or Plantae?

What is the effect of dengue fever on the platelets of blood in humans?

Who is credited with the discovery of viruses? Name the virus he discovered.