Keywords Flashcards
What is Variation?
Variation is the personality or characteristics of an animal, human or plant.
For example:
- Height
- Width
- Eye Colour
- Mass
- Colour
These can come within your Genetics or Environment you live in.
What is DNA?
DNA is short for Deoxyribonucleic Acid. This is the molecule that contains the genetic code of organisms.
What are Chromosomes?
Chromosomes are threadlike structures of nucleic acids and protein found in the nucleus. This is in a genetic formation making genes. Humans have 46 Chromosomes where as cats have 38. You get half of your chromosomes from your mother, and the other half from your father. In humans, sperm contains 23 chromosomes along with egg containing 23.
What are Genes/Genetics?
Genes are divided into sections of DNA, the sections that hold the information to produce your characteristics are genes. For example, genes select your eye colour, your hair colour.
Inheritance
Different versions of a gene, that code for different versions of a characteristic, are called alleles.
If the alleles in a matching pair are the same, they are called homozygous alleles.
If the alleles pair are different they are called heterozygous alleles.
Letters are always used to represent different alleles.
A dominant allele is always a capital letter.
A recessive allele is always the corresponding small letter.
These are always expressed in a Punnet Square or a Cross Square, like a Two Way Table.
Genetic Disorders
Genetic Disorders are problems that are passed down generations.
For example, Cystic Fibrosis is an inherited disease. This is where your lungs and digestive system are affected by a flow of mucus, which traps and removes bacteria.
Cloning
Cloning is when a cell or gene is removed from a living animal or plant, making a replica of itself.
Dolly the sheep was the first cloned mammal. Wilmut and his colleagues transplanted a nucleus from a mammary gland cell of a Finn Dorsett sheep into the enucleated egg of a Scottish blackface ewe. The nucleus-egg combination was stimulated with electricity to fuse the two and to stimulate cell division. This is done by cloning a cell.
Selective Breeding
Selective Breeding is when humans manipulate animals to produce an animal with the desired genes or traits.
For example, cows and big strong bulls have been used to breed together to get a strong big cow, carrying the desired genes.
But this isn’t easy, because most of the time there is 3:1 ratio of getting what you want. Especially when it takes a long for the female animal to give birth.
