Classification, Inheritance and Variation Flashcards
What is Classification?
Classification is the method used by scientists to order living organisms. All species have a unique classification that results in a binomial name. Vertebrates are an example of a classification group. Keys can be used to help to identify individual organisms
What is a kingdom?
The first rank in the classification system is called a kingdom
Name the five Kingdoms and what are they based on?
There are five kingdoms, based upon what an organism’s cells are like:
- animalia (all multicellular animals)
- plantae (all green plants)
- fungi (moulds, mushrooms, yeast)
- prokaryotae (bacteria, blue-green algae)
- protoctista (Amoeba, Paramecium).
Name the further divisions of classification?
There are several further ranks before we reach a particular species. In order, these are:
- kingdom
- phylum
- class
- order
- family
- genus
- species
For example, lions have the following classification:
- kingdom - animal
- phylum - vertebrate
- class - mammal
- order - carnivorous
- family - cat
- genus - big cat
- species - lion.
One way to remember this is by using a daft sentence like this one:
“Kevin plays clarinet or flute - grotty sound!”
What are all organisms known by?
All organisms are known by their binomial name which is the genus and species eg. Homo Sapiens - modern humans
Why is binomial classification important?
Binomial classification is important because it can:
- clearly identify species
- study and conserve species
- target conservation efforts.
Give characteristics and examples of the Animalia Kingdom?
Multicellular, no cell wall or chlorophyll, heterotrophic feeders. Examples: all multicellular animals, including: jellyfish, worms, arthropods, molluscs, echinoderms, fish, amphibia, reptiles, birds and mammals
Characteristics and examples of the Plantae kingdom
Multicellular, have cell walls and chlorophyll, autotrophic feeders. Examples: all green plants, including: algae, ferns and mosses (plants that do not produce seeds), conifers and flowering plants (plants that do produce seeds)
Characteristics and examples of the Fungi kingdom
Multicellular, have cell walls, do not have chlorophyll, saprophytic feeders. Examples: moulds, mushrooms, yeast
Characteristics and examples of the Protoctista kingdom
Usually unicellular, with a nucleus eg amoeba. Examples: amoeba and paramecium
Characteristics and examples of the Prokaryotes kingdom
Unicellular, with no nucleus eg bacteria. Examples: bacteria and blue-green algae
Example of classification of a species Homo Sapiens
- *Rank Classification Notes**
- *kingdom, animalia**
- *phylum,** chordates, animals with a supporting rod running the length of the body eg backbone
- *class,** mammals, animals that are warm-blooded, have lungs and body hair, produce milk and give birth to live young
- *order,** primates, ape-like animals
- *family,** hominids, human-like animals
- *genus,** homo, humans
- *species,** sapiens, modern humans
Certain organsims can be difficult to classify like Euglena, why?
Because it has:
- chloroplasts, like a plant
- no cell wall, like an animal
- a flagellum to swim with, like some bacteria
Why are viruses not classified as a living thing?
- it does not show all seven processes for life
- when it enters a cell it changes the way a cell works so it can make copies of the virus.
What are vertebrates?
Animals with a backbone
Scientists separate vertebrates into three further groups because of which features?
- how the animal takes in oxygen – lungs, gills or through the skin
- thermoregulation – maintains own temperature (homeotherms) or temperature varies with surroundings (poikilotherms)
- reproduction – internal or external fertilisation, lay eggs (oviparous) or give birth to live young (viviparous).
What is variation?
Organisms are adapted to survive in different conditions. Over many generations, these adaptations have come about through variation. Variation involves small changes between organisms which may allow that organism to compete better for survival. Variation can have environmental or genetic causes
Adaptation and Darwins theory on eveolution
Darwin’s theory of evolution explains how species of living things have changed over geological time. The theory is supported by evidence from fossils and by the rapid changes that can be seen to occur in microorganisms such as antibiotic-resistant bacteria. Many species have become extinct in the past, and the extinction of species continues to happen.
Wht are adaptation important?
Every organism has certain features or characteristics that allow it to live successfully in its habitat. Organisms living in different habitats need different adaptations
The polar bear and its adaptations to a cold climate
- a white appearance, as camouflage from prey on the snow and ice
- thick layers of fat and fur, for insulation against the cold
- a small surface area to volume ratio, to minimise heat loss
- a greasy coat, which sheds water after swimming.
What are the two types of variation?
- Continuous
- Discontinuous
What is continuous variation, name some exaples?
Any species a characteristic that changes gradually over a range of values shows continuous variation. Examples of such characteristics are:
- height
- weight
- foot length.
What is discontinuous variation, give examples?
A characteristic of any species with only a limited number of possible values shows discontinuous variation. Here are some examples of discontinuous variation:
- gender (male or female)
- blood group (A, B, AB or O)
- eye colour.
Variation within a species can be investigated. For example, if you were asked to find out if there was a link between the length of a pea pod and the number of seeds inside the pod you could:
- measure the length of a range of pea pods
- count the peas inside.
The experiment is made valid by controlling the variables.
The independent variable is length of the pea pod.
The dependant variable is the number of peas.
The control variables include:
- variety of pea plant
- time of year that the peas are selected.
The experiment is made reliable by further testing and achieveing a repeat of your results.
