Biodiversity And Taxonomy Flashcards
What is biodiversity?
With about 1.9 million species identified today, biodiversity is the total range of species diversity and relationships among species.
What is taxonomy?
The science of taxonomy helps grouping species into taxons. Classification into taxons is a subjective and rapidly changing field biology.
Recognizing the important characteristics used to differentiate organisms into taxons has some value, and forms the basis of the science of Taxonomy.
Story of classification.
At one point, classification what is mainly based on morphology, visible traits of an organism. With the evolution of technology however, classification is turning into molecular biology. Organism are redefined based on similarities in their chemical components (DNA,RNA and proteins organization).
What is the ranking order of taxonomic groups (from most to least inclusive)?
- Domain
- Kingdom
- Phylum
- Class
- Order
- Family
- Genus
- Specie
Organism in the same kingdom are very broadly similar ; those in the same phylum or more similar than those of another phyla.
How is organized taxonomy?
Since the 90s, the various species found on the Earth are divided into three domains:
-Domain Eukarya
-Domain Archea
-Domain bacteria
How are bacteria and archea different from eukaryotic cells ?
Mainly because they are prokaryotic ( meaning that they don’t have a membrane bound nucleus) and also for those 4 reasons :
1. Prokaryotic DNA is not contained within a membrane-bound nucleus.
2. The DNA in Prokaryotic cells is circular
3. Prokaryotic cell wall composition is biochemically different than eukaryotic cells
4. The size of prokaryotic cells is considerable smaller than eukaryotic cells
Domain Eukarya main characteristic and division
All organisms within the domain:
- share the same complex, compartmentalized cell called a eukaryotic cell.
- have multiple linear chromosomes
- have many specialized compartments known as organelles, including a nucleus which is membrane-bound and contains the nuclear material.
The domain is divided into 3 main Kingdoms:
-Plantae
-Animalia
-Fungi
All Eukarya that do not belong to the Kingdom Plantae, Animalia or Fungi are called Protists.
Characteristic common to Protista?
(Ex: algae, Protozoa, slime molds)
-mostly unicellular (can be multi but very simple)
-no specialized tissue
-Live in water and have various ways of nutrition (may be heterotrophic or photosynthetic)
Protist are often grouped:
-photoautrophic algae (plant-like protists)
-heterotrophic protozoans(animal-like protists)
- saprotrophic slime molds (fungus-like)
This group of extremely interesting organisms provides evidence that plants, animals, and fungi evolved from a common eukaryotic ancestor.
Characteristic common to the Kingdom fungi
Mostly multicellular, cell wall made of chitin, heterotrophic and absorb nutrient with no photosynthesis.
Can be:
- Saprophytes (live on dead organismic matter)
Most saprophytic fungi secrete digestive enzymes onto their food and then absorb the products of extracellular digestion.
-parasites (feed of living things)
Reproduction = sexual or asexual (spores are produced in both cases)
Kindom plantae
- composed of those organisms that are eukaryotic, multicellular, photosynthetic autotrophs. Their photosynthetic pigments are contained within membranous organelles called chloroplasts.
- well-defined cell wall made of cellulose
-sexual reproduction
-non-mobile
Kindom plantae
- composed of those organisms that are eukaryotic, multicellular, photosynthetic autotrophs. Their photosynthetic pigments are contained within membranous organelles called chloroplasts.
- well-defined cell wall made of cellulose
-sexual reproduction
-non-mobile
Kingdom animalia
-eukaryotic, multicellular, heterotrophic organisms
-mobile and sessile (non-mobile for part of their life cycle) in certain stages of their development.
- reproduction (sexual or asexual)
-kingdom is so broad that it is divided into phyla.
-nervous system coordinates responses to stimuli
