Classification Flashcards
Describe the 7 characteristics of living organisms
movement: an action by an organism or part
of an organism causing a change of position
or place
Respiration: the chemical reactions in cells that break down nutrient molecules and release energy for metabolism
sensitivity: the ability to detect and respond to
changes in the internal or external environment
growth: a permanent increase in size and dry mass
reproduction: the processes that make more of
the same kind of organism
excretion: the removal of the waste products
of metabolism and substances in excess of
requirements
nutrition: taking in materials for energy, growth
and development
Define Metabolism, dry mass, and growth
Metabolism: The chemical reactions that take place in living organisms
growth: a permanent increase in size and dry mass
dry mass: the mass of an organism after it has
been killed and all water removed from it
Define genus and species
genus: a group of species that share similar
features and a common ancestor
species: a group of organisms that can reproduce
to produce fertile offspring
What’s a dichotomous key?
dichotomous key: a way of identifying an
organism, by working through pairs of statements
that lead you to its name
What is a kingdom? Describe all 5
Kingdoms: one of the major groups into which all organisms are classified
Characteristic features of animals:
* Their cells have a nucleus, but no cell walls or
chloroplasts.
* They feed on organic substances made by other
living organisms.
Characteristic features of plants:
* 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).
Characteristic features of fungi:
* 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.
Characteristic features of protoctists:
* 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
Characteristic features of prokaryotes:
* 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.
Define spores, hyphae, and plasmids
Spores: very small groups of cells surrounded by a protective wall, used in reproduction
hyphae: microscopic threads, made of cells linked
in a long line, that make up the body of a fungus
plasmids: small circular molecules of DNA, found in many prokaryotic cellsin addition to the main, much larger circle of DNA
What’s a pinna, placenta, diaphram, and mammary gland
pinna: a fl ap on the outside of the body that
directs sound into the ear
placenta: an organ that connects the growing
fetus to its mother, in which the blood of the fetus
and mother are brought close together so that
materials can be exchanged between them
mammary glands: organs found only in
mammals, which produce milk to feed young
diaphragm: a muscle that separates the chest
cavity from the abdominal cavity in mammals;
it helps with breathing
Describe arthropods and the types
arthropod: an animal with jointed legs,
but no backbone
Characteristic features of insects:
* They are arthropods with three pairs of jointed legs.
* They have two pairs of wings (one or both may
be vestigial).
* They breathe through tubes called tracheae.
* Their body is divided into a head, thorax
and abdomen.
* They have one pair of antennae.
Characteristics of crustaneans
* They are arthropods with more than four pairs of
jointed legs.
* They have two pairs of antennae.
arachnid Characteristics:
* They are arthropods with four pairs of jointed legs.
* They have no antennae.
* Their body is divided into two parts –
a cephalothorax and abdomen
myriapods
Characteristics:
* Their body consists of many similar segments.
* Each of their body segments has jointed legs.
* They have one pair of antennae.
Define vestigial and trachea
vestigial: description of a structure that has
evolved to become so small that it is no
longer useful
trachea: tubes that inserts breathe through
Diffrenciate ferns and flowering plants
Characteristic features of ferns:
* They are plants with roots, stems and leaves
(fronds).
* They do not produce fl owers.
* They reproduce by spores produced on the
undersides of their fronds.
Characteristic features of flowering plants:
* They are plants with roots, stems and leaves.
* They reproduce using fl owers and seeds.
* Their seeds are produced inside an ovary,
in the fl ower
Define cotyledons. differenciate monotydeldons and dicotyledons
Flowering plants can be divided into two main groups –
dicotyledons and monocotyledons. These names refer to
the structure of their seeds. The seeds of fl owering plants
contain ‘seed leaves’ or cotyledons. Monocotyledons
(monocots for short) have only one cotyledon in their
seeds, whereas dicotyledons (dicots) have two
Characteristic features of dicots:
* They have seeds with two cotyledons.
* They usually have a main root with side roots
coming out from it.
* Their leaves have a network of veins.
* They have fl ower parts (e.g. petals) in multiples of
four or fi ve.
* They have vascular bundles in the stem, arranged in
a ring
Characteristic features of monocots:
* They have seeds with one cotyledon.
* Their roots grow out directly from the stem.
* Their leaves have parallel veins.
* They have fl ower parts in multiples of three.
* They have vascular bundles in the stem,
arranged randomly.
How do viruses work?
Viruses are not normally considered to be living
organisms because they cannot do anything other than
just exist until they get inside a living cell. They then
take over the cell’s machinery to make multiple copies of
themselves. These new viruses burst out of the cell and
invade others, where the process is repeated. The host cell
is usually killed when this happens. On their own, viruses
cannot move, feed, excrete, show sensitivity, grow or
reproduce. They do not display the seven characteristics
of living things.
How are modern classification techniques more accurate?
Biochemical and genetic analysis gives a more precise and detailed understanding about the relationships of organisms
WHat is an arthropod?
An invertebrate with an exoskeleton
WHat is a cotyledon?
an embryonic leaf in seed-bearing plants, one or more of which are the first leaves to appear from a germinating seed.
