What are the differences between alkanes, alkenes and alkynes?

What are the differences between alkanes, alkenes and alkynes? What are the differences between cis- and trans-isomers of alkenes? How are cis-trans isomers used for night vision?  Discussion Question 2  Using the South University Online Library or the Internet, research haloalkanes. Based on your research, respond to the following:  What is a haloalkane? Identify one of them. How does the haloalkane you identified function as an anesthetic? Describe in detail.