A3.1 Diversity of Organisms Flashcards
taxonomy
the science of classification
taxis
arrangement
taxa
groups or categories within a classification system
3 objectives for using binomial nomenclature (1)
To be sure that each organism has a unique name that cannot be confused with another organism;
3 objectives for using binomial nomenclature (2)
So that the names can be universally understood, no matter what nationality or culture is using the name;
3 objectives for using binomial nomenclature (3)
So that there is some stability in the system by not allowing people to change the names of organisms without valid reasons
A hierarchy of taxa
Lol, Does Kenny Play Classical Or Folk Guitar Songs?
Life
Domain
Kingdom
phylum
class
order
family
genus
species
Distinguishing between populations and species: wolly mammoth
Previously classified as Elephas primigenius because it shared many similar characteristics with Asian elephants (Elephas maximus)
Difficult to confirm because mammoth extinct and there are no live ones to study
Therefore, now classified as Mammuthus primigenius
chromosomes in humans
46
chromosomes in chimpanzees
48
what is genome
genome refers to the total of all the genetic information in an organism
do organisms of the same species share the same genome
Organisms in the same species share most of their genome but variations such as single-nucleotide polymorphisms give some diversity
Karyotype
An individual’s complete set of chromosomes, the number and types of chromosomes in a eukaryotic cell
Karyogram
Chromosomes arranged as homologous pairs in descending order of size
shows the gender of the individual and whether he’she has genetic disease like Down Syndrome (extra chromosomes)
Diversity of eukaryotic genomes
Genomes vary in overall size, which is determined by the total amount of DNA. Genomes also vary in base sequence. Variation between species is much larger than variation within a species
mitochondrial DNA
Mitochondria and chloroplasts are organelles that contains their one circular DNA
It is believed to be one of the evidence of the endosymbiosis theory - mitochondria were once aerobic bacteria and chloroplasts were once cyanobacteria got engulfed by ancestral prokaryotes
Current and potential future uses of whole genome sequencing
Include the increasing speed and decreasing costs.
For current uses, include research into evolutionary relationships and potential future uses, include personalised medicine
Applications for whole genome sequencing
Apply genome sequencing to study the evolutionary relationships of different species - phylogenetics
Apply genome sequencing to personalise disease treatments (different types of cancer) and medications to make them more effective and reduce side effects
Research on what other possible usage on this technology
what group of organisms does the biological species concept not work well with
The biological species concept does not work well with groups of organisms that do not breed sexually or where genes can be transferred from one species to another
examples of organisms that can reproduce asexually
Some species of insects like aphids and stick insects can reproduce without a male
Many plants can reproduce asexually, vegetative propagation (bulb, corm tuber, rhizome, runners, cuttings,…)
Bacteria reproduce using binary fission and able to carry out plasmid transfer to exchange genetic material with other bacteria (to increase genetic variation for survival, for example they can share antibiotic resistant genes)
are viruses organisms
They are small infectious agents (small size and simple composition) that replicates inside living cells of other organisms like animals, plants and bacteria
They can also have gene transfer with other organisms (we have some viral DNA in us and also our ancestors passed down some of the viral DNA that then they picked up during the viral infection in their lifetime)
Dichotomous key
A dichotomous key is an identification tool mainly used by scientists to classify and identify organisms into particular categories based on their traits
what does a dichotomous key consist of
The key consists of a series of paired statements or clues about features or characteristics, providing a stepwise guide towards identifying each entity
DNA barcoding
DNA barcoding is a method of organism identification using short, standardised segments of DNA (hundreds bp) found in the organisms and comparing them to the database. Every species has its own barcode, just as every person has their own fingerprint
Limitations of analysing environmental DNA
lacking information about the amount of the species and how the species interact with other living things, as well as how the DNA got to the environment
