Questions

Mixed economy is the most common economic system in the world.

The population increases in geometrical progression and has crossed the 5 billion mark. The united nations estimate an average growth rate of 1.5% per annum.

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.

In the above options, sperms are the haploid cells. In humans, haploid cells are those have only half the number of usual number of chromosomes. Sperm, gamates and egg cells are the haploid cells examples.

When two or more chemical species combine to form a single product, the reaction is said to be synthesis reaction. It is also called as Direct Combination reaction.

Here in the given options, Sodium (Na) combines with Chlorine (Cl) to form a more complex single product Sodium Chloride (NaCl).