chapter 1 - characteristics and classification of living organisms Flashcards
*Define:
movement
an action by an organism or part of an organism causing a change in position or place.
*Define:
respiration
the chemical reaction in cells that break down nutrient molecules and release energy for metabolism.
most organisms require oxygen.
*Define:
sensitivity
the ability to detect/ sense stimuli in the internal or external environment and to make appropriate responses.
*Define:
growth
a permanent increase in size and dry mass by an increase in cell size, cell number or both.
*Define:
reproduction
the process that makes more of the same kind of organism.
*Define:
excretion
the removal from organisms of waste products or metabolism, toxic materials and substances in excess of requirements.
*Define:
nutrition
the taking in of materials for energy, growth and development.
plants require CO2 + water + light + ions.
animals need organic compounds + usually water.
*Define:
species
a group of organisms that can reproduce to produce fertile offspring.
*How are organisms classified?
organisms can be classified into group by the features that they share.
they are classified in a way that allows them to be further divided into smaller, more specialized groups.
*what is classification usually based on?
it is traditionally based on studies of morphology and anatomy.
what is morphology?
study of the form or outer appearance.
what is anatomy?
study of internal structure as revealed by dissection.
*explain how our knowledge of DNA helps in classification?
sequences of bases in DNA and of amino acids in proteins are used as a more accurate means of classification.
*Define:
binomial system
an international agreed system of naming in which the scientific name of an organism is made up of 2 parts showing it genus and species.
binomial means 2 names.
*explain what is the aim of the classification system?
classification systems aim to reflect (make us understand) evolutionary relationships.
*explain how organisms who share more recent ancestors will be more closely related than those who only share distant ancestors.
organisms who share more recent ancestors are more closely related because they have more similar DNA base sequences than those that share only a distant ancestor.
what is meant by:
multicellular
an organism consisting of many cells.
what is meant by:
unicellular
an organism consisting of one cell only.
what is meant by:
eukaryotes
an organism whos cell have a “true nucleus”.
what is meant by:
prokaryotes
an organism whos cells do not have a nucleus.
what is meant by:
autotrophic
organisms that can make their own food.
what is meant by:
heterotrophic
organisms that feed on organic substances made by other living things.
*main features of the animal kingdom:
1- multicellular
2- eukaryotes
3- heterotrophic
4- their cells do not have cell walls or chloroplast.
*main feature of the plant kingdom:
1- multicellular
2- eukaryotes
3- autotrophic
4- their cells have cell walls made of cellulose and chloroplasts containing chlorophyll.
*main features of the animal kingdom:
1- multicellular 2- eukaryotes 3- heterotrophic 4- their cells do not have cell walls or chloroplast. 5- reproduce sexually
*main feature of the prokaryote kingdom:
1- aka bacteria 2- unicellular 3- prokaryotes 4- some are autotrophic (blue-green algae), some are heterotrophic. 5- reproduce by binary fission.
*main feature of the protoctists kingdom:
1- unicellular
2- eukaryotes
3- some are autotrophic (called protophyta), some are heterotrophic (called protozoa).
what are the groups within the animal kingdom?
1- vertebrates: mammals, birds, fish, reptiles and amphibians.
2- invertebrates (arthropods): myriapods, insects, arachnids, crustaceans.
