Can there be mitosis without DNA replication in ‘S’ phase?

The arrangement of ovules within the ovary is known as placentation. What does the term placenta refer to? Name the different types of placentation seen in plants. Draw any three types of placentation in flowers as seen in T.S.

Some varieties of wheat are known as spring wheat while others are called winter wheat. Former variety is sown, and planted in spring and is harvested by the end of the same season. However, winter varieties, if planted in spring, fail to flower or produce mature grains within a span of a flowering season. Explain, why?

Comment upon the gametic exchange in earthworm during mating.

Sunflower is not a flower. Explain.

Trace the events starting from the coming in contact of Rhizobium to a leguminous root till nodule formation. Add a note on importance of leg hemoglobin.

Name the two important enzymes of C4 pathway, and explain their role in fixing CO₂?

Oxygen is critical for aerobic respiration. Explain its role with respect to ETS.

Lichen is usually cited as an example of ‘symbiosis’ in plants where an algal and a fungal species live together for their mutual benefit. Which of the following will happen if algal and fungal partners are separated from each other?

a. Both will survive and grow normally and independent from each other.

b. Both will die

c. Algal component will survive while the fungal component will die.

d. Fungal component will survive while algal partner will die. Based on your answer how do you justify this association as symbiosis.

How does a muscle shorten during its contraction and return to its original form during relaxation?

What special anatomical features are displayed by leaves of C4 plants? How do they provide advantage over the structure of C3 plants?