Are there any individuals that are genetically identical?
No
What does karyotyping mean?
It is used to determine the number and type of chromosomes present in a sample set of cell.
All females have how many barr bodies?
1
What is a barr body?
condensed X chromosome near nucleus of cell
(An inactive cell)
What stain is used to determine the presence of Y chromosomes?
Acridine orange
What is autosomal nondisjunction?
It's when non-sex chromosomes fail to separate during meiosis.
ex: down syndrome (trisomy 21)
What does nondisjunction mean?
A failure of chromosomes to separate during meiosis.
How does a nonviable syndrome occur?
0Y
How does jacob's syndrome occur?
XYY
How does down syndrome occur?
When there are 3 chromosomes 21 (trisomy 21)
What is the gamete for Klinfelter's syndrome?
XXY (male) - 1 barr body
What is the gamete for Turner's syndrome?
0X (female) - no barr bodies
What does DNA stand for?
Deoxyribonucleic acid
True or false. DNA is found in all living cells?
True
What are the 3 parts of DNA?
sugar, phosphate, and a nitrogen base
What is the shape of DNA
A helix
Where is DNA found in the cell?
The nucleus and mitochondria
What is the role of DNA?
It encodes for all cellular protein
When does DNA replicate?
During the S phase of interphase in cell division
Why was strawberries used in the experiment to extract DNA?
Because it has a lot of DNA making the chromosomes visible to the naked eye.
What are the 3 steps for DNA isolation?
1. Homogenization
2. Deproteinization
3. Precipitation
What happens in homogenization?
The cell and nucleus are broken down to release the DNA
What happens in deproteinization?
Detergent/buffer is used to remove protein from DNA. (Meat tenderizer)
What happens in preciptation?
Ice-cold alcohol(ethanol) is used to separate DNA from other cell debris. (It will float to the top)
DNA is composed of what?
Nucleotides
What are the four nitrogenous bases of DNA?
adenine, guanine, cytosine, and thymine
What is a group of 3 amino acids called?
codon
What is the initiation codon?
AUG - to start protein sysnthesis
What is the stop codons?
UAA, UAG, UGA
How do the nitrogenous bases pair?
Adenine and thymine pair and form a double bond. Cytosine and guanine pair and form a triple bond.
What are the 2 nucleotide bases?
Pyrimidines(C/T) - 1 ring
Purines(A/G) - 2 rings
For RNA what base pair is substituted? And what is responsible for this?
U (uracil) for T
RNA polymerase is responsible for this
What does translocation mean?
When a portion of 1 chromosome is transferred to another. (not usually nonhomologous)
What is the process of transcription?
DNA to mRNA
What is the process of translation?
mRNA to protein
Leading vs lagging strand?
Leading - 3' to 5'
Lagging - 5' to 3'
What does helicase do?
Its an enzyme that unwinds a parental double helix
What is the specific step that helps DNA become a protein?
messenger RNA
What is evolution?
It is the change in a populations allelic frequency over time?
What is a mendelian population?
Sexual reproducing individuals that are able to interbreed.
What is a gene pool?
The genotypic frequency and the allelic frequency within the population. (Basically, the set of genes in a population)
What is the Hardy-Weinberg law?
If certain conditions are met, then allelic frequencies in a population will not change form generation to generation.
What is a genetic drift?
When allelic frequencies change with time in small populations.