Why only left ovary and oviduct are present in birds?

Show that only odd harmonics are present in the vibrations of air column in a pipe closed at one end.

Why is only carbon used and not any other element for defining atomic mass unit?

Why do racer cars and birds have typical shape ?

Crop and gizzard are present in digestive system of birds. Give reason.

What is the single term that answers all the following question? OR What decides whether you are blue eyed or brown eyed? OR Why does wheat grain germinate to produce what plant and not rice plant? OR Which acid molecules are present in nuclei of living cells?

Read the following paragraph and answer the questions based on it. Rhizobium living in root nodules supply nitrates, nitrites and amino acids to that plant and in exchange get energy in the form of carbohydrates from it. Such a mutually beneficial relationship is called symbiosis. Rhizobium produce nitrogenous compounds from atmospheric nitrogen. However, for this process of nitrogen fixation, they need leguminous plants like beans, sweet pea, soyabean, etc. as ‘host’. Beans and pulses are rich in proteins due to the nitrogenous compounds made available by Rhizobium. After harvesting a leguminous crop, the left-over roots and other plant parts are deliberately dumped in farm soil to maintain its bacterial population. The use of Rhizobium has helped to reduce the use of chemical fertilizers and thereby their adverse effects. It has also helped to reduce expenses on fertilizers and thus works to the benefit of farmers. Why does left over roots and other plant parts are deliberately dumped in farm soil after harvesting a leguminous crop?

How many ovarioles are present in the ovary of cockroach.

Why do lanslides occur at those places only ?

Why is methionine always present in the beginning of each simple protein molecule?