DNA: the code of life Flashcards
Full name of DNA
Deoxyribonucleic acid
Organisms with no nucleus
prokaryotes e.g. bacteria
Location of DNA in eukaryotes
Nucleus
Also in:
- Mitochondria in plants and animals
- Chloroplasts in plants
Examples of eukaryotic kingdoms
- plants
- animals
- fungi
- protists
DNA and proteins forming a dense network of fibres in the nucleus
Chromatin
Parts of the nucleus include
- Double nuclear membrane
- Nucleoplasm
- Chromatin/DNA and proteins
- Nucleolus
Phase of a cells cycle when the chromatin condenses into distinct chromasomes
Prophase of Mitosis and Meiosis
How do you make a karyotype & what do we use it for?
- Cut out images of a cells chromosomes
- Arranged in pairs and numbered in order of size
- Shows chromosomal content of cells
- Can be used to diagnose chromosome level genetic disorders
Number of chromosomes in humans
46 chromosomes (23 pairs)
Sex chromosomes for a female and a male
- XX = females
- XY = males
A gene is?
- A specific portion of DNA
- with a specific sequence
- that determines a particular characteristic of an organism.
What exactly do genes code for?
Protein molecules
DNA not containing genes
non-coding DNA
Extra-nuclear DNA often referred to as mtDNA and cpDNA
mitochondrial DNA and chloroplast DNA
Reason for adding salt in a DNA extraction
To condense DNA and proteins after cells have burst
Reason for adding detergent in a DNA extraction
To remove membrane lipids
Reason for adding protease (e.g. meat tenderiser) in a DNA extraction
To remove proteins from membranes and chromatin
Reason for adding ice cold alcohol in a DNA extraction
To purify the DNA as DNA forms a solid precipitate in the alcohol
Initially credited with identifying the double helix structure of DNA
- James Watson
- Francis Crick
- (in 1953)
Performed the X-ray diffraction and photographed it to help discover the structure of DNA
- Rosalind Franklin
- Maurice Wilkins
Repeating units making up DNA are called…
Nucleotides
Composition of one nucleotide
- Phosphate
- Deoxyribose
- Nitrogenous base
The five different nitrogenous bases
- A-Adenine
- T-Thymine
- C-Cytosine
- G-Guanine
- U-Uracil
Purine bases
- Adenine
- Guanine