Genetics Flashcards
Genetic variation
Characteristics that are inherited, caused by genes from both our parents
Examples of genetic variation
Eye colour, natural hair colour, blood group
Environmental variation
Characteristics caused by the surroundings around an organism
Examples of environmental variation
Length of hair, sunburn
Mixed variation (genetic & environmental variation)
Characteristics caused by a mix of both genetics and environment
Examples of mixed variation
Height, weight, handspan
Monogenic traits are usually………. are displayed with a …….. ……..
Monogenic traits are usually discrete (easily put into groups or categories) and are displayed with a bar chart
Polygenic traits
Traits caused by several genes ( not very easily put into categories)
Polygenic traits are usually………. and are displayed with a …………..
Polygenic traits are usually continuous (cannot be placed into distinct categories) and are displayed with a histogram
Discrete variation
Data that can be easily placed into distinct groups or categories
Continuous variation
Data that cannot be placed into distinct groups or categories, with values being placed in a range between two extremes
Order of the genetic structure
Cell, nucleus, chromosome, DNA molecule, gene, allele
Chromosome
Found within the nucleus and have a molecule of DNA a wrapped up inside of them
Gene
A short section of DNA
Each gene code is used to make …….. ……. ….. …. …..
Each gene code is used to make specific protiens in the body, which create different cell types
DNA stands for ……………… …….
Deoxyribonucleic acid
Why do chromosomes exist in pairs?
One chromosome is inherited from each parent
How many chromosomes do humans have in each cell?
46 chromosomes or 23 pairs
How are characteristics inherited?
During fertilisation, the nuclei of the egg and sperm fuse together. In each gamete, there is an incomplete set of 23 chromosomes and when these fuse, they create a zygote of 46 chromosomes which will develop into an embryo of a genetic mix of both the mother and father.
Why is the 23rd pair of chromosomes so important?
It determines the sex of the human. If there are 2 X chromosomes in the final pair, it’s a female. If there is one X and one Y chromosome in the final pair, it’s a boy.
