Chapter 4: Genetics And Evolution Flashcards
Genetics
Is the study of how characteristics are passed on from one generation to another.
There are two types of characteristics
Inherited characteristics
Acquired characteristics
Inherited characteristics
Are passed on from parents to their children by genes. For example, hair colour, blood type and the ability to roll your tongue.
Acquired characteristics
Are not inherited from our parents. They are learned throughout our life. For example, the accent we speakin in or being able to ride a bike.
Chromosomes
Chromosomes are thread-like structures found in the nucleus of an animal or plant cell. They are made up of protein and a chemical called DNA (deoxyribonucleic acid)
Gene
A gene is a short section of the DNA is a chromosome. Each gene contains the information needed to make a different protein in a cell. Proteins make up everything in our bodys, such as enzymes, muscles, bones, hair and teeth.
Gamete
Gametes are the cells involved in reproduction.
The male gamete
Sperm, 23 chromosomes
The female gamete
Egg, 23 chromosomes
Zygote
During human reproduction the male sperm and the female egg fuse and a single cell called a zygote is formed.
It contains 46 chromosomes.
The dominant gene is called
The dominant gene, will show in a child even if only one parent has the dominant gene
The non-dominant gene
The recessive gene, will only show if both parents pass the recessive gene on to the child.
Species
A species is a group of similiar organisms that can breed with each other to produce fertile offspring.
Variation
Describes all of the differences in traits that exist in members of the same species.
Natural selection
Is the process by which the members of a species who are best suited to the environment are most likely to survive and reproduce.
