Genetic Processes Flashcards
What is genetics (definition)
study of genes, heredity, and variation of organisms
Major Fields of Genetics (3)
Transmission genetics
Molecular genetics
Population genetics
Epigenetics
New genetic field
Epigenetics = turning genes on/off
E.g. what women eat affects eggs → eating habits, lifestyle
Jobs involved in genetics
Medical research scientist
Scientific laboratory technician
Genetic counselor
Trait (definition)
characteristic of an organism
traits can be inherited or acquired
Inherited traits
Traits from our ancestors
E.g. 1 eye colour from mom, 1 eye colour from dad
Inherited traits come from chromosomes → found inside nucleolus
Acquired traits
traits from environmental change
E.g. dyeing hair (sunbleached), gaining weight, freckles from sun
What is DNA?
deoxyribo nucleic acid
DNA is organized into genes
What are genes
Distinct part of a cell’s DNA, which are coded instructions for making everything the body needs, especially protein
Carry distinct code for specific inherited traits
Alleles
allele: variations of the same gene found on the same place of the chromosome
- We all carry the same types of genes, but the alleles we carry and are expressed accounts for variation
- The dominant version of the allele is expressed, the recessive alleles are not expressed, but can be passed down to the next generation
- i.e. everyone has genes that determine eye colour, but not everyone has the same versions of those genes (alleles), which means that not everyone has the same eye colour
- e.g. someone with a brown eye (dominant) and blue eye (recessive) allele combination will have brown eyes - Their children could have blue eyes if they have two blue eyed alleles
Eukaryote vs Prokaryote
Eukaryotes have a membrane-bound nucleus
* Prokaryote = before nucleus
* Eukaryote = full nucleus
Chromatin
Combination (DNA + protein), very thin, not visible under light microscope
- Resembles big bowl of spaghetti
- DNA in chromatin tightly coiled around histones (proteins)
- DNA in histones package structures called nucleosomes (looks like beads)
- Coils up to form chromosomes
- Coiling prevents damage
- Chromatin coils when leaves nucleus
- Outside of chromosome is not coding
Chromosomes
Definition + how many total
One long condensed DNA molecule with hundreds of thousands of genes inside
* Coiled up version of chromatin
* 46 total = 23 from each parent
* Human body cell has enough DNA to stretch 2m long
Watson and Crick
What did they invent + its basic structure
Invented double helix model of DNA
* Sugar-phosphate backbone (outside of 2 helix subunits)
* Nitrogenous bases (on inside) = where genetic information is stored, coding occurs here
DNA Structure
DNA molecule consists of two polynucleotide chains, which form a double helix structure
* Molecules of DNA made up of long chain of tiny subunits called nucleotides, which form a polynucleotide chain
