Genes & Genome Flashcards
Define Genome
All the DNA of an organism
Since when do humans have their genome?
Since fertilisation
What are the three main types of DNA?
Nuclear DNA, mitochondrial DNA, and Chloroplast DNA
What are possible traits of nucleotide sequences?
They are genes
Regulatory (on/off)
Non-coding (Introns)
Tandem Repeats (repetitive)
What is a Gene?
A heritable factor that consists of DNA and influences specific characteristics
OR
A sequence of DNA nucleotides that codes for a RNA or protein product
Define Locus
A specific location on a chromosome where a gene is located
OR
A specific location on a gene
Define allele
A different variation of the same gene
Give an example of an alelle
A gene encodes for the eye Color brown, dependent on the parents, the alternative code may be for blue eyes
How are new alleles formed?
Through mutations
What is a chromosome
Supercooled DNA and associated structural proteins
What is chromatin
A string of DNA wrapped around histone proteins
What is Gene expression
The process by which a gene creates a product
When is the X shape of a chromosome seen?
Only seen in prophase and metaphase when a cell has replicated its DNA and is dividing.
What does a chromosome look like when its not dividing?
Like one leg of a chromosome pair
Letters for homozygous dominant
AA
Letters for heterozygous
Aa
Letters for homozygous recessive
Aa
How are alleles of the same gene the same?
They are the same gene and both code for the same type of protein(eg hair Color). They occupy the same locus on homologous (similar) chromosomes and the majority of the sequence remains the same between alleles.