Biology π | Characteristics and Organization | 1.1 Flashcards
What are the 7 characteristics of living organisms?
Movement, Respiration, Sensitivity, Growth, Reproduction, Excretion, Nutrition. (MRS GREN)
Define βMovementβ.
Actions by an organism or part of an organism causing a change in position or space. This may be to avoid predation or access food.
Define βRespirationβ.
The chemical reactions in cells that break down nutrient molecules and release energy for metabolism.
Define βSensitivityβ.
The ability to detect or sense stimuli in the internal or external environment and to make appropriate responses in order to survive.
Define βGrowthβ
A permanent increase in size and dry mass by an increase in cell number or cell size or both.
Define βReproductionβ
The processes that makes more of the same kind of organism.
Define βExcretionβ
Removal from organisms of the waste products of metabolism, toxic materials, and substances in excess of requirements.
Define βNutritionβ
Taking in of materials for energy, growth and development
To be considered living, how many of the 7 characteristics does the organism have to have?
A thing needs all 7 characteristics to be considered living, though there are exceptions such as interbred species and infertile animals.
Define βSpeciesβ
A group of organisms with similar features that can reproduce and produce fertile offspring.
What is interbreeding?
When two organisms can reproduce but produce infertile offspring. Though they can reproduce they are not a part of the same species.
What is a common ancestor?
A species that lived long ago believed to be a distant ancestor of two or more species living today.
What are the basic ways that we can classify organisms?
- Morphology
- Anatomy
Define morphology
The overall form and shape of an organism, and physical appearance
Define anatomy
The detailed body structure of an organism as determined from dissection
How does DNA help us classify organisms?
We can see how similar the base sequences of DNA on two species are.
What does two organisms having a more similar base sequence of DNA mean?
It means that they have a closer common ancestor.
What is the aim of classification systems?
To try and reflect evolutionary relationships, allowing us to see how the current living world developed.
What are the 7 base categories a species is classified to in the Linnaean classification system?
Kingdom - Phylum - Class - Order - Family - Genus - Species.
Define the binomial system of naming species
An internationally agreed system in which the scientific name of an organism is made up of two parts showing the genus and species
How is the scientific name of a species written?
The Genus name of a species capitalized and italicized, and the species name italicized in lower case put together.
(Genus species)
What are the five kingdoms?
Prokaryotes, Protoctista, Plants, Fungi, and Animal.
What is a dichotomous key?
A scientific tool to help us classify and identify different direction, using branches of two descriptions in each statement.
What are the characteristics of animals?
- Multicellular
- Contains a nucleus
- No cell walls or chloroplasts
- Feed on organic substances made by other living things
What are the characteristics of plants?
- Multicellular
- Contains a nucleus, chloroplasts, and cellulose cell walls
- Feed by photosynthesis
What are the characteristics of Fungi?
- Usually multicellular
- Contains nuclei
- Non-cellulose cell walls
- Feeds by saprophytic (on dead or decaying material) or parasitic (on live material) nutrition
What are the characteristics of protoctists?
- Most are unicellular; rarely multicellular
- All have a nucleus; some have cell walls and chloroplasts
- Some photosynthesise, some feed on other organic material
What are the characteristics of prokaryotes?
P - Prokaryotes have no nucleus.
R - Ribiosomes and DNA loop in the cytoplasm, Non cellulose cell wall
O - Often unicellular
PROkaryotes
What do all cells share?
Cell membrane, cytoplasm, ribosomes, and enzymes.
What are the phylums animals are divided into?
Vertebrates and arthropods (invertebrates).