Genetics Flashcards
What are the two types of characteristics?
Acquired characteristics e.g riding a bike
Inherited characteristics e.g hair colour
How many genes are in each human body?
20,500
How many chromosomes do humans have?
Every human body cell contains 46 chromosomes, except gametes.
What are gametes?
Gametes are the cells involved in reproduction. The male gamete is a sperm. The female gamete is an egg. They both contain 23 chromosomes
What is natural selection?
the process by which the members of a species who are best suited to their environment are most likely to survive and reproduce.
What is mutation?
a change in the gene or chromosome
What are examples of environmental causes of mutation?
Smoking
UV rays in sunlight destroy the DNA of skin cells.
Exposure to gamma rays or X-rays
Who invented the theory of natural selection?
Charles Darwin
What is variation?
describes all of the differences in traits that exist in members of the same species.
What is a dominant gene?
A dominant trait will show in a child even if only one parent has the dominant gene.
What is a recessive gene?
A recessive trait will only show if both parents pass the recessive gene on to the child.
