How many parts of a comet are there?

There are three:  a nucleus, a coma, and a tail.

Explanation:

image result for what happens whenever a net force acts on an object

if an object has a net force acting on it, it will accelerate. the object will speed up, slow down or change direction. an unbalanced force (net force) acting on an object changes its speed and/or direction of motion. an unbalanced force is an unopposed force that causes a change in motion.

ans.

gregor john mendel is known for study of inheritance in pea plants. he used garden pea plant for his study, having alternative traits for various characters. he performed cross-breeding in pea plants to check how characters are transmitted between parents to offspring, such as cross between pure tall and pure dwarf plant. mendel studied the inheritance patterns in pea plants for various generations.

thus, the correct answer includes options and f).