UNIT 3.1 Flashcards
(22 cards)
DNA
genetic blueprint which codes and determines the characteristics of an origin
Packed and organized into structures called chromosomes
Genes
A heritable factor that consists of a specific length of DNA and that encodes for a specific trait
Recessive Gene
Allele that is not expressed in the heterozygous genotype(minority)
Dominant Gene
Allele that is expressed in the heterozygous genotype (majority)
Genome
Consists of the entire genetic material of an organism
Chromosomes
Long DNA molecules which contain many genes
Eukaryotes stored in the nucleus
Prokaryotes circular found form
Diploid
A pair of each kind of chromosome
Haploid
One copy of each chromosome
Histone
a type of protein found in a chromosome
Locus
The position of a gene on a particular chromosome
Alleles
An alternative form of a gene that code for different variations of a specific trait (occupies the same locus as other alleles of the same gene)
Homozygous
two copies of the same allele
Heterozygous
two different alleles
Genome Vs. Proteome
Genome
Same Nucleus:
Non-coding sequences:
Human Genomes
Proteome
Genome: specific number for the total genetic information
INFO:
Chloroplast and mitochondria have their own nucleus
Includes non-coding DNA sequence: introns, promoters, short tandem repeats)
Human Genomes:
46 chromosomes
3 billion base pairs
21,000 genes
Proteome: specific number for the total proteins a species has
Human Genome Project (HGP)
Outcomes (4):
The Human Genome Project (HGP) was an international cooperative venture established to sequence the human genome
* The HGP showed that humans share the majority of their sequence, with short nucleotide polymorphisms contributing to diversity
Completion of the Human Genome Project in 2003
1) Mapping – The number, location, size and sequence of human genes is now established
2) Screening – This has allowed for the production of specific gene probes to detect sufferers and carriers of genetic diseases
3) Medicine – The discovery of new proteins has led to improved treatments (pharmacogenetics and rational drug design)
4) Ancestry – Comparisons with other genomes have provided insight into the origins, evolution and migratory patterns of man
Gene Comparison
Escherichia Coli (bacteria):
Gallus gallus (chicken):
Homo Sapiens:
Daphnia pulex (water flea):
Oryza sativa: (arroz)
*Check Good Notes for Diagram
Escherichia Coli (bacteria): 4200
Gallus gallus (chicken): 17,000
Homo Sapiens: 21,000
Daphnia pulex (water flea): 31,000
Oryza sativa: (arroz): 38,000
Base pairings
Homo Sapiens:
T2 Phage:
Canopu Plant:
Escherichia Coli
Fruit Fly:
Homo Sapiens: 3.2
T2 Phage: 164,000
Canopu Plant: 150,000
Escherichia Coli: 4.6 billion
Fruit Fly: 130 billion
Mutations
What is formed?
Beneficial:
Detrimental:
Neutral:
Gene mutation: A permanent change in the nucleotide sequence of a sanction of DNA coding for a specific trait
New alleles are formed by mutation
They can be beneficial, detrimental or neutral:
Beneficial mutation (missense): create new variations of a trait
Detrimental mutations (nonsense): abrogate the normal function of a trait
Neutral mutations (silent): no effect on the functioning of a feature
Sickle Cell Anemia
*Check Good Notes for Diagram
Disease allele arose from a base substitution mutation: a single base was changed in the gene sequence
Produces abnormal red blood cells
Sickle Cell Anemia: Causes
*Check Good Notes for Diagram
Results from a change to the 6th codon for the beta chain of haemoglobin
DNA: Template strand: CTC → CAC
mRNA : GAG → GUG in the 6th codon position
Polypeptide: The sixth amino acid for the beta chain of haemoglobin is changed from glutamic acid to valine (Glu → Val)
Sickle Cell Anemia: Consequences (2)
*Check Good Notes for Diagram
Consequences of Sickle Cell Anaemia
- Amino acid from glutamic acid to valine (Glu → Val)
- Glutamic acid: polar
- Valine: non-polar → causes it to form insoluble fibrous strands
- Instead of normal globular haemoglobin → clumped fibrous haemoglobin
Formation of fibrous haemoglobin changes the shape of the red blood cell → sickle shape
* May form clots within the capillaries → blocks the blood supply to vital organs + causes myriad health issues
* Destroys more rapidly than normal cells → Low red blood cell count → anaemia → Constant fatigue
Sickle Cell Anemia with Malaria
Carried by who:
People with this:
*Check Good Notes for Diagram
Parasitic disease caused by plasmodium cell
*Carried by the Anopheles mosquito and invades normal red blood cells causing them to lyse (disintegrate)
*People with sickle cell disease are resistant to sickle cell disease
*Sickle cell is more prevalent where malaria is endemic (local)
