01) Characteristics and classification of living organisms Flashcards
1.1. Describe the 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: the taking in of materials for energy, growth and development
2.1. How can organisms be classified into groups?
By the features that they share
2.2. Describe a species
A group of organisms that can reproduce to produce fertile offspring
2.3. Describe the binomial system of naming species
Sequence of classification: Kingdom, Phylum, Class, Order, Family, Genus, Species
“King Phillip Cooks Orphans For Good Servants”
The scientific name is made up genus and species
Genus capitalised, species lowercase, always underlined/italicised
(e.g.) Erinaceus europaeus
2.5. Explain that classification systems aim to reflect evolutionary relationships
Traditional biological classification systems used the features that they shared
Morphology: the overall form and shape (e.g. wings or legs)
Anatomy (aka PAIN if you’re an artist who draws humans): detailed body structure as determined by dissection
Organisms were said to be more closely related if they shared similar features
Using the physical features of species (such as colour/shape/size) has many limitations and can often lead to the wrong classification of species
2.6. Explain that the sequences of bases in DNA are used as a means of classification
Organisms share features if they originally descended from a common ancestor
(e.g. all mammals have bodies covered in hair, feed young from mammary glands and have external ears)
Microscopes, biochemistry and DNA sequencing are a more scientific means
Proteins made up from a chain of amino acids, and there are 20 types
Similarities and differences in these sequences can provide information about evolutionary relationships
The more similar the base sequences in the DNA of two species, the more…
Closely related those two species are
Recent in time their common ancestor is
The base sequences in a mammal’s DNA are more closely related to all other mammals than to any other vertebrate groups
2.7. What do more similar base sequences in DNA between two species indicate?
They shared a more recent ancestor
Cladograms represent groups of organisms that evolved from a common ancestor
3.1/4.1. State the main features used to place all organisms the animal kingdom
Multicellular, nucleus, no cell wall or chloroplasts
Feed on organic substances made by other living things
(e.g. sponges, worms, insects, fish, amphibians, reptiles, birds and mammals)
3.1/4.2. State the main features used to place all organisms the plant kingdom
Multicellular, nucleus, chloroplasts and cellulose cell wall
Feed by photosynthesis
(e.g. mosses, ferns, woody and non-woody flowering plants)
3.1/4.3. State the main features used to place all organisms the fungus kingdom
Mostly multicellular, nuclei and cell walls not made from cellulose
Feed by saprophytic (on dead or decaying material) or parasitic (on live material) nutrition
(e.g. mushrooms, yeast, mould)
3.1/4.4. State the main features used to place all organisms the prokaryote kingdom
Often unicellular, cell walls (not cellulose) and cytoplasm, no nucleus/mitochondria
Absorb food
(e.g. bacteria, blue-green algae, spirochetes)
3.1/4.5. State the main features used to place all organisms the protocist kingdom
Most are unicellular, all have a nucleus and some have cell walls and chloroplasts, large single cell, some form chains or colonies
Some feed on organic substances and some photosynthesise
(e.g. protozoans like amoeba and algae)
3.2.1.1. State the main features used to place organisms into mammals
Skin with hair or fur
Internal fertilisation
Internal development of eggs, birth to live young
Teeth
No beak (except platypus)
External ears
Warm-blooded
Mammary glands produce milk
3.2.1.2. State the main features used to place organisms into birds
Feathers
Internal fertilisation
Eggs with hard shell
No teeth
Beaks
Internal ears
Warm-blooded
Wings
Flight (most)
3.2.1.3. State the main features used to place organisms into reptiles
Dry scales
Internal fertilisation
Eggs with leathery shells
Simple teeth
No beaks
Internal ears
Cold-blooded
3.2.1.4. State the main features used to place organisms into amphibians
Moist skin
External fertilisation
Eggs with no shell (soft)
No teeth
No beaks
Internal ears (most)
Cold-blooded
Semi-aquatic
3.2.1.5. State the main features used to place organisms into fish
Scales
External fertilisation
Eggs with no shell (soft)
Teeth (some)
No beaks
Internal ears
Cold-blooded
No legs - fins
Gills
3.2.2.1. State the main features used to place organisms into myriapods
Clear head, other parts similar
One pair of antannae
Compound or simple eyes, or none
Many legs
No wings
Trachea
3.2.2.2. State the main features used to place organisms into insects
Three parts: head, thorax abdomen
One pair of antannae
One pair of compound eyes
Three pairs of legs
Wings
Trachea
3.2.2.3. State the main features used to place organisms into arachnids
Two body parts: cephalothorax and abdomen
No antannae, chelicerae
Simple eyes
Four pairs of legs
No wings
Book gills
3.2.2.4. State the main features used to place organisms into crustaceans
No obvious body divisions
Two pairs of antannae
A pair of compound eyes
Many legs
No wings
Gills
3.5.1. State the main features used to place organisms into groups within the plant kingdom, limited to ferns and flowering plants
Ferns: leaves called fronds, reproduce through spores produced on the underside of fronds
Flowering plants: reproduce sexually by flowers and seeds (produced inside the ovary), divided into monocotyledons (e.g. wheat plants) and dicotyledons (e.g. sunflowers)
3.5.2. State the main features used to place organisms into groups within the plant kingdom, limited to dicotyledons and monocotyledons
Monocotyledon: multiples of 3, parallel leaf veins, vascular bundles scattered throughout stem, fibrous root system
Dicotyledon: multiples of 4 or 5, reticulated (branching) leaf veins, vascular bundles arranged in a ring, tap root
3.7. State the features of viruses
Viruses are not part of any classification system as they are not living things, instead taking over a host cell’s metabolic pathways in order to make multiple copies of themselves
Genetic material (RNA or DNA) inside a protein coat
