Genetics Flashcards
gene
parts of DNA that carry hereditary information
allele
different versions of a gene
dominant
shows its specific trait even if only one parent passed the gene to the child
recessive
shows its specific trait when both parents pass the gene to the child
genotype
hereditary information that contain genetic code
phenotype
expressed traits
homozygous
two of the same form of a gene –> same alleles (AA or aa)
heterozygous
two different forms of one gene –> different alles (Aa or AB)
genome
entire genetic material
evolution
change in the inherited characteristics of a population over time through a process of natural selection which may result in the formation of new species
example of evolution through natural selection
antibiotic resistant bacteria
causes of variation (genetical)
- mutation
- recombination –> sexual reproduction
- crossing over through mitosis
- migration
migration
any form of the introduction of genes from one population to another –> different allele frequencies
causes of variation (environmental)
- climate
- diet
- accidents
Exp: flower colour in hydrangeas (these plants produce blue flowers in acidic soil and pink flowers in alkaline soil)
continuous variation
characteristic that changes gradually over a range of values shows continuous variation –> height
discontinuous variation
characteristic of any species with only a limited number of possible values shows discontinuous variation –> blood group
selective breeding
humans breed particular animals/plants for particular genetic characteristics
procedure of selective breeding
decide on characteristics
choose parents that best show characteristics
choose offspring that best shows characteristics
risks of selective breeding
reduced genetic variation –> species prone to certain diseases
rare disease genes accidentally selected
physical problems due to not being formed correctly
procedure of genetic engineering
selection of characteristics
isolation of responsible gene
insertion into other organism
replication of transgenic organism
transgenic organism/ GMO
genetically modified organism
an organism that carries a gene from another organism
isolation
restriction enzymes
isolation of mRNA –> reverse transcriptase produces single strand of complementary DNA
recombinant DNA
DNA of the Plasmid that combined with the DNA of the host
somatic cell
body cell
codominant
genes that have alleles that are equally dominant
–> both expressed equally in the phenotype
polygenic characteristics
characteristics controlled by more than just one gene
monohybrid inheritance
inheritance of characteristics inherited only by a single gene
–> refers to the process of crossing rather than a theoretical crossing with the exact ratio outcomes
pure breeding
individuals are homozygous for that gene
cross
Kreuzen
does a pedigree chart show the phenotypes or genotypes?
phenotypes
autosomal
not affecting the sex chromosomes
dominant allele
capital letter ; Allele that is phenotypically expressed over another allele
recessive allele
Allele that is only expressed in absence of a dominant allele ; lower case letter
What has to be excluded from a calculation concerning the ratio of offsprings having certain alleles?
dead offsprings
can a mutation result in getting a genetic condition?
YES
What can you assume when the disease skips no generations?
dominant
Can males who are affected by a X-linked disease give the disease to their sons?
No, because they give the sons the Y chromosome
What are the five key properties of the genetic code#ß
1) universal –> same code used across all species
2) composed of nucleotide triplets
3) unambiguous (eindeutig) –> same codon encodes from same amino acid/ start/ stop
4) non-overlapping –> each nucleotide part of one codon
5) degenerate –> several codons can encode for the same amino acids
What kind of disorder are sex-linked recessive disorders?
Who definitely has the disorder?
X-linked –> each male has disorder
Can men of a sex-linked recessive disorder that is lethal at birth be carriers?
No, if they have the malicious X chromosome, they die and won’t reproduce
Where does mitochondrial DNA come from?
inherited from the mother
Who can get an X-linked recessive disease?
only men because they have only one x
