๐ | Unit 1 & 2 | Characteristics, Classification and Organization of Living Organisms Flashcards
What do animals need for nutrition?
Animals require organic compounds, ions and usually water
How are organisms usually classified?
Organisms can be classified into groups by the features that they share
What happens when the species get more and more subdivided?
The species in these groups have more and more features in common the more subdivided they get
What is the sequence of classification?
Kingdom, Phylum, Class, Order, Family, Genus, Species
Why do organisms share features?
Organisms have features in common because they originally descend from a common ancestor
How were organisms classified originally?
They were classified using morphology and anatomy
How were organisms classified as technology advanced?
As technology advanced, organisms were classified using microscopes, knowledge of biochemistry and DNA sequencing, which allowed us to classify organisms in a more scientific approach
What did studies of DNA sequences of different species show?
Studies of DNA sequencing of different species showed that the more similar the base sequences in the DNA of two species are, the more closely related they are
What are DNA sequences used to code for?
DNA sequences are used to code for amino acid sequences in proteins
Can amino acid sequences be used to determine how closely related organisms are?
Yes, amino acid sequences can also be used to determine how closely related organisms are
Why arenโt viruses a part of any classification system?
Viruses are not part of any classification system because they are not considered living things
Do viruses carry out the seven life processes?
No, viruses do not carry out the seven life processes. Instead, they take over the host cellโs metabolic pathways to make multiple copies of themselves
What is the structure of a virus?
A virus structure is genetic material (DNA or RNA) inside a protein coat
The cells of all organisms containโฆ
- cytoplasm
- DNA as genetic material (either in the nucleus or spread around the cytoplasm)
- a cell membrane
When observed under an electron microscope, all cells also containโฆ
โฆribosomes for protein synthesis, and enzymes for respiration (enzymes are usually found in mitochondria)
The five kingdoms organisms are
Animals, Plants, Fungi, Protoctists, Prokaryotes
What is saprophytic?
Saprophytic means to feed on dead or decaying material
What is parasitic?
Parasitic means to feed on live material
What two categories can animals be split into?
Vertebrates and invertebrates
What is a common feature of vertebrates?
All vertebrates have a backbone
Classes of vertebrates
Mammals, birds, amphibians, reptiles and fish
Main features of mammals
โข have fur/hair on skin
โข have a placenta
โข young feed from mammary glands
โข have external ears
โข endothermic
Main features of birds
โข have feathers on skin
โข lay eggs with hard shells on land
โข have two wings and two legs instead of forelimbs
โข have a beak
โข endothermic
Main features of amphibians
โข have smooth, moist skin
โข lay eggs without shells in water
โข adults usually live on land (so they have lungs), larvae live in water (so they have gills)