Task 1 Flashcards
Define “Phenotype”
The observable characteristic determined by our genotype.
What is the basic chain of events, how the DNA affects our phenotype?
DNA -> mRNA -> Amino Acids -> Proteins -> Phenotype
What is the technical term for when a phenotypic characteristic is controlled by multiple genes?
Poly-genetic characteristics
Finding out about the specific function of a single gene can be done using two main study designs.
Linkage Studies:
- > Examine large families, in which members differ in a certain phenotype
- > Study genotype of the family members for alleles that correlate with certain variations in the phenotype
Association Studies:
- > Take a test group with a certain phenotype and one without it
- > Test for genome differences
- > Requires many genetic markers
What is the main content and result of the prairie voles study?
- PV’s form long term bonds after mating. This is triggered by the protein Arginine Vasopressin. Genes that code for this protein have different coding sequences in PV’s.
Why do we need to account for the environment, even when looking at the effects of genes?
External influences can change the way or frequency of how a gene gets expressed.
This can also happen prenatally, especially in the first trimester of pregnancy.
- Inheritance of phenotypes can also be a product of social learning and not inheritance.
- Quality of maternal care effects the methylation of genes, which can decrease gene expression
What does the central dogma of molecular genetics say?
Change happens from genome over RNA, amino acids, proteins, to phenotype and only in this direction.
What are alleles?
Different variations of a gene; Locus on DNA that codes for sth specific.
What is the difference between Mitosis and Meiosis?
Mitosis:
- cell division whereby cells split into genetically identical copies
- making more phenotype
- somatic cells do this
Meiosis:
- Cell division, whereby a haploid gamete/ germ cell is produced
- making more phenotype and genotype
- present only in sperm/egg cells in humans
Describe the structure of DNA
- wound around proteins called histones
- Double Helix
- backbone made out of sugars & phosphates
- > Strong bond
- Four nucleic bases attached between the helixes
- the bases are connected in pairs and have weak hydrogen bonds
- Bases are paired: A-T, C-G
What are the four nucleic bases and their classes?
A - Adenine - Purin (bigger)
T - Thymine - Pyramidin (smaller)
G - Guanine - Purin (bigger)
C - Cytosine - Pyramidin (smaller)
Describe which areas of our genome are coding vs non-coding
- A small amount of our genome is coding for something
- within genes, we have introns (non-coding) and exons (coding)
- > ~1% is actually coding
What happens with introns?
Introns are transcribed but not translated. Splicing cuts them away before this.
What does DNA Polymerase do?
- The molecule that goes along the strands of DNA after separation and reads the DNA and then builds the mRNA from it.
- reads from 3’ -> 5’; builds from 5’ -> 3’ in the leading strand
- As the lagging strand is the other way around, DNA Polymerase has to translate a segment of the DNA (against coding direction) and then start further down the strand again. -> Okazaki Segments
Where is DNA located?
In our cell nucleuses
- We also have DNA in the mitochondria of our cells
