Mention any two abiotic factors that affect crop production.

Find out the correct sentence:
$(i)$ Hybridisation means crossing between genetically dissimilar plants.
$(ii)$ Cross between two varieties is called as inter-varietal hybridisation.
$(iii)$ Introducing genes of desired character into a plant gives genetically modified crop.
$(iv)$ Cross between plants of two species is called as inter-specific hybridisation.

Ram's teacher was showing the structure of a cell under a compound microscope,highlighting different parts like the cell wall,cell membrane,and nucleus. The teacher explained the difference between plant and animal cells,noting that the cell wall is found only in plant cells. Everyone observed the structure carefully and understood its structural importance.
$(a)$ What kind of qualities are shown by Ram?
$(b)$ Why is the cell called the structural and functional unit of life?

Vividha told Vasudha that she will show her some magic. Vividha took a metallic pipe. She asked Vasudha to hold one of its ends close to her ears. She gently tapped the other end of the pipe with a metallic object. She asked Vasudha what she heard. Vasudha said she heard two sounds.
$(a)$ Was this magic? Why did Vasudha hear two sounds?
$(b)$ What values are imbibed by Vividha?

For good production of poultry birds,what kind of management practices are important?

It is observed that the number of asthmatic patients is increasing day by day. It is due to urbanization,industrialization,and excessive use of vehicles. Sidak's mother took some initiatives to reduce this problem. She,along with her son and his friends,prepared data on the destinations colony people visit,the different routes taken,and the timings of their jobs,and arranged for carpooling.
$(a)$ Explain the reason for the growing number of asthmatic patients.
$(b)$ Explain the values shown by Sidak's mother.
$(c)$ Suggest other methods to reduce this problem.