Characteristics and classification of living organisms Flashcards
Movement
an action by an organism or part of an organism causing a change of position or place.
Respiration
chemical reactions in cells that break down nutrient molecules and release energy for metabolism
Sensitivity
ability to detect or sense stimuli in the internal or external environment and make appropriate responses
Reproduction
processes that make more of the same kind of organism.
Excretion
removal of metabolic wastes, toxic substances, and substances in excess of requirements from the body.
Nutrition
taking in of materials for energy, growth and development.
Organisms can be classified into groups by
the features that they share.
Species
group of organisms that can interbreed among themselves and produce fertile offsprings
Binomial system
of naming species is an internationally agreed system in which the the scientific name of an organism is made up of two parts showing the genus and
species.
Classification systems aim to
reflect evolutionary relationships.
The sequences of bases in DNA are used as a
means of classification.
Groups of organisms that share a more recent ancestor (are more closely related)
have
base sequences in DNA that are more similar than those that share only a
distant ancestor.
5 kingdoms
animal , plants , fungus, protocist, prokaryote
Animal kingdom
Their cells have a nucleus, but no cell walls or chloroplasts.
They feed on organic substances made by other living organisms.
Plant kingdom
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 (but some plants do not have these organs).
Fungus
They are usually multicellular (many-celled), but some such as yeast are unicellular (single-celled).
They have nuclei and cell walls, but the walls are not made of cellulose.
They do not have chlorophyll.
They feed by digesting waste organic material and absorbing it into their cells.
Protoctista
They are multicellular or unicellular.
Their cells have a nucleus and may or may not have a cell wall and chloroplasts.
Some feed by photosynthesis and others feed on organic substances made by other organisms.
Prokaryote
They are usually unicellular (single-celled).
They have no nucleus.
They have cell walls, not made of cellulose.
They have no mitochondria.
They have a circular loop of DNA, which is free in the cytoplasm.
They often have plasmids.
Vertebrates are animals that
have a backbone:
examples: fish, amphibians, reptiles, birds, mammals
fish
They are vertebrates with scaly skin.
They have gills throughout their life.
They have fins.
Their eggs have no shells and are laid in water.
Amphibians
They are vertebrates with skin with no scales.
Their eggs have no shells and are laid in water.
The tadpoles live in water, but adults often live on land.
The tadpoles have gills for gas exchange, but adults have lungs.
Reptiles
They are vertebrates with scaly skin.
They lay eggs with soft shells on land.
Birds
They have feathers (and also sometimes a few scales).
They have a beak.
Their front two limbs are wings (though not all birds can fly).
They lay eggs with hard shells.
Mammals
They have hair on their skin.
Their young develop in a uterus, attached to the mother by a placenta.
The females have mammary glands, which produce milk to feed their young.
They have different kinds of teeth (incisors, canines, premolars and molars).
They have a pinna (ear flap) on the outside of the body.
They have sweat glands in the skin.
They have a diaphragm.
