Chapter 1 - Characteristics and Classification of living organisms Flashcards
Definition of “Organism”
A living thing.
What are the 7 characteristics of a living thing.
MRSGREN: Movement, Reproduction, Sensitivity, Growth, Respiration, Excretion, Nutrition
Definition of “Common Ancestor”
A species that lived in the past and is thought to have given rise to several different species alive today.
Definition of “Species”
A group of organisms that can reproduce to produce fertile offspring.
Definition of “Genus”
A group of species that share similar features and a common ancestor.
The Binomial naming system
A system of naming species that is internationally agreed, in which the scientific name is made up of two parts, showing the genus and he species. The first letter of the Genus is always written in Capital letters.
Dichotomous Key
A way of identifying an organism, by working through pairs of statements that lead you to its name.
Example:
1a. It has four legs ………. It is a horse
1b. It has 2 legs ………. Go to 2.
2a. It has wings ………. It is a Owl
2b. It has scales ………. Go to 3
…
Definition of “Evolution”
The process by which organisms have developed.
Comparative Anatomy
The similarities in the anatomical structure of different species which can help with identifying the specie’s classification. However this may not be reliable since some species with similar anatomy may be very distantly related.
DNA Sequence Classification
This makes possible distinguishing one species from another, it’s useful to look at similarities, but also differences. With this we are able to tell how much similar are two different species.
Genome
A complete set of genetic information from a species.
Definition of “Kingdoms”
One of the major groups into which all organisms are classified.
These divide into six kingdoms:
-The Animals Kingdom
-The Plant Kingdom
-The Fungus Kingdom
-The Protoctist Kingdom
-The Prokaryote Kingdom
Characteristics of an Animal
-They are multicellular organisms.
-Their cells have a nucleus, but no cell walls or chloroplasts.
-They feed on organic substances made by other living organisms.
Characteristics of a Plant
-Their cells have a nucleus and cell walls made of cellulose and often contain chloroplasts.
-they feed by photosynthesis.
-They may have roots, stems and leaves (though some plants do not).
Definition of Cellulose
A carbohydrate that forms long fibres and makes up the cell walls of plants.
