When a few individuals go away from a population, the population loses some genes. What is the name of this phenomenon. Explain?

When two different genes came from same parent they tend to remain together. What is the name of this phenomenon?

When two different genes came from same parent they tend to remain together. (i) What is the name of this phenomenon? (ii) Draw the cross with suitable example. (iii) Write the observed phenotypic ratio.

What do we learn from identification of individuals and populations?

A laboratory blood test is 99% effective in detecting a certain disease when it is in fact, present. However, the test also yield a false positive result for 0.5% of the healthy person tested (i.e. if a healthy person is tested, then with probability 0.005, the test will imply he has the disease). If 0.1 percent of the population actually has the disease, what is the probability that a person has the disease given that his test result is positive?

A laboratory blood test is 99% effective in detecting a certain disease when it is in fact, present. However, the test also yields a false positive result for 0.5% of the healthy person tested (i.e. if a healthy person is tested, then, with probability 0.005, the test will imply he has the disease). If 0.1 percent of the population actually has the disease, what is the probability that a person has the disease given that his test result is positive ?

A population has more young individuals compared to the older individuals. What would be the status of the population after some years ?