( UNIT 05 ) Genetics Flashcards
Gene mapping
Determining the location of genes on chromosomes.
List the Chromosome Mutations (4)
- Deletion
- Duplication
- Translocation
- Inversion
Deletion
A piece of a chromosome is broken off and ‘deleted’.
Duplication
An extra piece of a chromosome is attached to an existing chromosome, duplicating some genes.
Translocation
A piece of a chromosome breaks off and attaches to a non-homologous chromosome.
Inversion
A piece of a chromosome detaches, flips, then reattaches.
What are sex-linked genes?
Genes located on the sex chromosomes (X or Y). The X chromosome has more sex-linked genes.
Why are Recessive sex-linked traits more common in males than females?
Traits that are more common in males than in females due to the presence of a single X chromosome in males.
Autosomes
Non-sex chromosomes. Humans have 22 pairs of autosomes.
Structure of DNA
Double helix with alternating deoxyribose sugars and phosphate groups. Nitrogen bases: Adenine, Thymine, Cytosine, Guanine.
DNA Replication
- DNA unwinds and the bases separate.
- Each strand serves as a template for the synthesis of a new complementary strand.
- DNA polymerase adds nucleotides to the new strand.
- Two identical DNA molecules are formed.
Structure of RNA
Single helix with ribose sugar. Nitrogen bases: Adenine, Uracil, Cytosine, Guanine.
Protein synthesis
The process of creating proteins from the instructions encoded in DNA. Consists of transcription and translation.
Transcription
- DNA unwinds and the gene’s DNA sequence is transcribed into mRNA.
- RNA polymerase adds complementary RNA nucleotides.
- mRNA is formed and can leave the nucleus.
Translation
- mRNA attaches to a ribosome.
- tRNA brings the correct amino acids to the ribosome.
- Amino acids are joined together to form a protein.
Gene regulation
The ability of an organism to control which genes are transcribed in response to the environment.
Hox genes
Genes that determine the body plan of an organism and code for transcription factors. Important in embryonic stem cells.
Least dangerous gene mutation
Substitution, because it only affects a single nucleotide.
What are DNA fingerprints used for?
Used for identification purposes by analyzing unique patterns in an individual’s DNA.
3 types of RNA
tRNA , mRNA , rRNA
Restriction Enzymes in DNA fingerprinting
Cut long DNA molecules at different locations .
Gel Electrophoresis
Process of moving molecules with an electric current ; gel is semi-permeable .
Which chemical is radioactive in DNA fingerprinting?
Probes
In karyotyping , which areas are darker on the chromosome ?
Regions rich in base pairs (AT)
