Genetics Flashcards
The study of heredity
Genetics
Passing on characteristics (traits) from parents to offspring so offspring resemble parents and each other
Heredity
Microbial Traits include… (4)
- Shape/Structure (morphology)
- Biochemical Reactions
- Movement and Behavior
- Interactions with other organisms
Actual, expressed properties or characteristics
Phenotype
Organisms genetic makeup (total collection of genes)
Genotype
Total genetic material in a cell, total DNA or RNA
Genome
Any factor affecting the expression of the phenotype other than the genes
Environment
Genotype + environment –> Phenotype
Genes in cells are always composed of…
Double stranded DNA
Genes hold the coded information that determines (4)
- The sequence of mRNA which determines the primary structure of a polypeptide
- The sequence of rRNA
- The sequence of tRNA
- The sequence of regulatory RNA
The flow of biological information… (6)
- Genes (genotype)
- mRNA and other RNA
- Polypeptide primary sequence
- Proteins (enzymes)
- Regulates cell chemistry
- Determines morphology and phenotype
Polymer of deoxyribonucleotides
DNA
Polymer of ribonucleotides
RNA
DNA and RNA differ in the… (2)
- Nitrogenous bases they contain
2. Sugars they contain
DNA nitrogenous bases… (4)
- Adenine
- Thymine
- Cytosine
- Guanine
True or Flase: In all cells DNA is always a double stranded helix?
True
The purines are?
Adenine and Guanine
The pyrimadines are…
Cytosine, Uracil, and Thymine
Adenine and thymine are paired by…
2 hydrogen bonds
Cytosine and Guanine are paired by…
3 hydrogen bonds
How many base pairs make up one turn on the helix?
10 base pairs
The diameter of double stranded DNA is?
2 nm
RNA bases…
- Adenine
- Uracil
- Cytosine
- Guanine
Nucleic Acids contain this type of bond?
Phosphoodiester
RNA structure (single stranded?)
Most RNA molecules are single stranded, some are double stranded or have double stranded regions
3 types of RNA
- mRNA
- rRNA
- tRNA
Characteristics of Viral Genomes
- Either DNA or RNA- never both
- Single stranded or double stranded
- Very little or no proteins
- Linear or circular
- 20-100 genes
- 20,000-100,000 nucleic acids
- Viral genomes are packed within a capsid
What is a capsid?
Viral genomes are packed into a protein coat
Characteristics of Prokaryote Genomes
- Double stranded DNA
- 98% DNA and 2% proteins
- Linear, circular, or supercoiled
- Single piece of DNA as their bacterial chromosome
- 2000-5000 genes
- 2 -5 million nucleotides
- Contain plasmids
What are plasmids?
Small pieces of open circular double stranded DNA in the cytoplasm
Eukaryotic Genome Characteristics
- Always composed of double stranded DNA
- Linear or circular
- DNA is spread over many eukaryotic chromosomes
- Several chromosomes
5.
All members of the same species have the same number of chromosomes?
Species Number or Chromosomal Number
What is the purpose of chromosomes?
Organizing a lot of DNA in a little volume
What are the components of the eukaryotic chromosome?
- 35% DNA
- 64% proteins (histones and non histones)
- 1%RNA