Questions

While plant cells have chloroplasts to photosynthesize, they also require ATP for cellular functions, and do use oxygen to break down some of the sugar they produce in order to generate that ATP. Cellular respiration takes place in the mitochondria. They need mitochondria for this reason.
Hence with this logic, we can say that Plants cells have mitochondria.

Gamma rays has the shortest wavelength and radio waves has the longest wavelength.

Activation of the receptors by stimuli is called Sensation.

Hedging is a tool to minimize the risks. It is thus like an 'insurance' where one pays a premium but gets an assured amount in case of some uncertain event to the extent of the loss actually suffered on an equally opposite position for which the hedge was done. Thus, hedger is different from arbitrageur and speculators, as the intention here is not to maximize the profit but to minimize the loss.

E.g. In Capital Markets, suppose an investor has an equity portfolio of Rs. 2 lacs and the portfolio consists of all the major stocks of NIFTY. He thinks the market will improve in the long run but might go on a downside in the shortrun. NIFTY today stands at 4300. To minimize the risk of downfall, he enters into an option contract by buying NIFTY-PUT of strike 4300 at a premium of, say, Rs. 100. Thus, the actual amount paid is Rs. 5,000(lot size of NIFTY is 50). Also, the number of NIFTY-PUTs to be bought will vary on the beta of the portfolio so as to completely hedge the positon.