6.1 The relationship between species
Two criteria to determine whether individuals belong to the same species:
1. Agreement in appearance
2. Ability fertile offspring may getto
Today also used DNA analysis to determine whether two organisms of the same species
Species described = scientific name -> binomial nomenclature -> 2 parts:
1. The genus name -> with capital letter
2. The species designation -> with small letter
Sometimes there is an extra letter behind the name -> L -> name of addition / subspecies = geographically separated
group of congeners with slightly different characteristics
Taxonomy = the science that divides species into groups: (large to small)
1. Domains
2. Realms
3. Departments
4. Classes
5. Orders
6. Families
7. Genera
8. Species
9. Organisms
By breeding animals / cultivating plants -> variations -> races -> no part of taxonomy Taxonomy
distinguished 3 domains -> each with its own type of rRNA (ribosomal RNA):
- The archaea
- Prokaryotes -> single-celled without nuclear membrane
- Circular DNA lies loose in the cell
- The structure of the cell membrane -> the membrane consists of a single layer of phospholipids with long fat-
like tails
- Bacteria
- Cell membranes have a double layer of phospholipids
- Eukaryotes
- Cell membranes have a double layer of phospholipids
- DNA in the cell nucleus
Biologists use DNA research to arrive at a more reliable classification of species -> they analyze genes for proteins that
occur in many different organisms, such as the hemoglobin gene -> genes that mutate at a constant rate form a
molecular clock -> be able to determine which species are related and how long these species are present on earth:
- Almost the same hemoglobin gene = closely related species
- Mutations in the hemoglobin gene = less closely related species + longer since they split from a common ancestor
Hybrids = viable offspring of different species -> help to map family relationships between species -> DNA must be
largely the same
Asexual reproductionreproduce = without mating -> criterion fertile offspring is canceled
Two criteria to determine whether individuals belong to the same species:
1. Agreement in appearance
2. Ability fertile offspring may getto
Today also used DNA analysis to determine whether two organisms of the same species
Species described = scientific name -> binomial nomenclature -> 2 parts:
1. The genus name -> with capital letter
2. The species designation -> with small letter
Sometimes there is an extra letter behind the name -> L -> name of addition / subspecies = geographically separated
group of congeners with slightly different characteristics
Taxonomy = the science that divides species into groups: (large to small)
1. Domains
2. Realms
3. Departments
4. Classes
5. Orders
6. Families
7. Genera
8. Species
9. Organisms
By breeding animals / cultivating plants -> variations -> races -> no part of taxonomy Taxonomy
distinguished 3 domains -> each with its own type of rRNA (ribosomal RNA):
- The archaea
- Prokaryotes -> single-celled without nuclear membrane
- Circular DNA lies loose in the cell
- The structure of the cell membrane -> the membrane consists of a single layer of phospholipids with long fat-
like tails
- Bacteria
- Cell membranes have a double layer of phospholipids
- Eukaryotes
- Cell membranes have a double layer of phospholipids
- DNA in the cell nucleus
Biologists use DNA research to arrive at a more reliable classification of species -> they analyze genes for proteins that
occur in many different organisms, such as the hemoglobin gene -> genes that mutate at a constant rate form a
molecular clock -> be able to determine which species are related and how long these species are present on earth:
- Almost the same hemoglobin gene = closely related species
- Mutations in the hemoglobin gene = less closely related species + longer since they split from a common ancestor
Hybrids = viable offspring of different species -> help to map family relationships between species -> DNA must be
largely the same
Asexual reproductionreproduce = without mating -> criterion fertile offspring is canceled
