DNA - double helix of complementary polynucleotides
What are genes?
Regions of chromosomal DNA encoding the amino acid sequence of a polypeptide
What causes hereditary variation?
variant forms of genes known as alleles
What is evolution?
Consequence of genetic changes in a population over time
How long is a single haploid genome?
1 meter long
How long is a single DNA strand?
2 meters long - 2 single haploid genomes make up one DNA strand
How many sets of alleles do you carry? Where do you get them?
2 sets from mother and 2 sets from father = 4 sets total
Describe phenotypic traits and where do the come from?
Characterization of organisms by their appearance or physiology, sorting individuals into observable groups (ex: blue eyes, height, blood type, having sickle cell anemia) - These traits come from our alleles
What type of letter signifies a dominant phenotypic trait?
Upper case letters
What type of letter signifies a recessive phenotypic trait?
Lower case letters
What is the definition of genetics?
experimental science/study of heredity
Who discovered the principles of heredity?
What are the 6 levels of genetics that we can study?
1. Organism level (human) 2. Cellular Level 3. Chromosomal level (including banding) 4. Single Specific Chromosomal Pair Level 5. Where the genes are located 6. DNA sequence level
basic complement of DNA of an organism
Define "haploid" and what types of species fall into this category?
contain only one copy of a genome (fungi, algae, bacteria)
Define "diploid" and what types of species fall into this category?
contain two copies of their genomes (most plants and animals)
What lineage is tracked using mitochondrial markers?
Different forms of the same gene, located in the same position along the chromosome in each individual.
Define "heterozygous" and give example
gene pair with two different alleles in two chromosome sets (ex: A/a)
Define "homozygous" and give example
gene pair with identical alleles in both copies (ex: A/A)
How are chromosomes numbered?
Larger chromosomes have smaller numbers and smaller chromosomes have larger numbers
Name 2 bi-genomic species
humans and fungi
Name a tri-genomic species
Name the genomes in plants
mitochondrial, nuclear, chloroplast
Name the genomes in humans and fungi
mitochondrial and nuclear
How many bonds connect A - T? How many bonds connect G - C? Which pair have stronger bonds?
2 hydrogen bonds 3 hydrogen bonds G - C pair is stronger; while A - T is easier to break
Name the three chemical components of DNA
phosphate, deoxyribose sugar, and one of the four nitrogenous bases
Name the four nitrogenous bases
Adenine - A Guanine - G Cytosine - C Thymine - T
Define "purine" and which nitrogenous bases are considered to have this structure?
long molecules, double-ring structure - Adenine & Guanine
Define "pyrimidine" and which nitrogenous bases are considered to have this structure?
short molecules, single-ring structure - Cytosine & Thymine
How are base pairs joined together?
What is the distance between base pairs on a double helix?
0.34 nm (top to bottom)
What is the distance of one turn of DNA molecule (double helix)?
How many base pairs in one turn of a double helix?
10 base pairs
Where is the minor groove located?
where the double helix is closer together (1.4 nm)
Where is the major groove located?
where the double helix is farther apart (2 nm)
What is the distance of the diameter of a double helix?
linear chain of amino acids (polypeptide), encoded by gene, subject to variation
What is considered the "central dogma"
the understanding that: DNA --> mRNA --> polypeptide (protein)
Identify the process of transcription...
DNA --> mRNA
Identify the process of translation...
mRNA --> polypeptide (protein)
What is the first amino acid in any polypeptide? What is the 3 letter code?