biology 2 Flashcards
classification
Characteristics of Living Things (MRS GREN):
MRS GREN: Movement, Respiration, Sensitivity, Growth, Reproduction, Excretion, Nutrition.
- Define Species:.
Species: A group of organisms that can reproduce and form fertile offspring
- Binomial System of Naming a Species:
The binomial system uses two names: the genus (capitalized) and species (lowercase), e.g., Homo sapiens.
. Organisms Classified by Shared Features:
Organisms are classified based on shared features or structures, reflecting their evolutionary relationships.
- Past Classification (Morphology & Anatomy):
Historically, classification was based on morphology (structure) and anatomy (internal features).
- Modern Classification (DNA Sequences):
Modern classification uses DNA sequences to classify organisms accurately, revealing evolutionary relationships.
- Features Used for Classification into the Four Eukaryotic Kingdoms:
Animals: Multicellular, no cell walls, heterotrophic, e.g., mammals, birds, fish.
Plants: Multicellular, autotrophic, with cell walls (cellulose), e.g., ferns, flowering plants.
Fungi: Multicellular or unicellular, saprotrophic, with cell walls (chitin), e.g., mushrooms, yeasts.
Protoctista: Unicellular or simple multicellular, eukaryotic, diverse modes of nutrition, e.g., algae, amoeba.
- Features of Prokaryotes:
Prokaryotes: Unicellular, lack a nucleus, smaller than eukaryotes, e.g., bacteria.
Grouping Organisms within the Animal Kingdom:
Vertebrates: Mammals, birds, reptiles, amphibians, fish.
Arthropods: Myriapods, insects, arachnids, crustaceans.
Grouping Organisms within the Plant Kingdom:
Ferns and flowering plants (e.g., dicots and monocots).
- Viruses:
Viruses: Consist of a protein coat and genetic material, not considered living organisms.
- Using Dichotomous Keys:
A dichotomous key helps identify organisms by asking yes/no questions about their specific characteristics or features.
