Unit 1 - Characteristics and classification of living organisms Flashcards
The 7 characteristics of living organisms
Movement, Respiration, Sensitivity, Growth, Reproduction, Excretion, Nutrition
Movement
An action by an organism, or part of an organism, that causes change in position or place
Sensitivity
The ability to detect and respond to stimuli in the internal or external environment
Growth
The permanent increase in size and dry mass
Reproduction
The process that makes more of the same kind of organism
Excretion
The removal of waste products of metabolism and substances that are in excess of requirements
Nutrition
The absorption or ingestion of materials for the purpose of providing energy, growth and development
System of classification
The binomial system
Order of classification in the binomial system
Kingdom, Phylum, Class, Order, Family, Genus, Species
DNA
The molecule of inheritance found in the nucleus of cells
The four bases of DNA
A,T,C,G
The complementary base pairs in DNA sequences
A&T , C&G
5 kingdoms
Prokaryotes, Protoctists, animals, plants, fungi
Vertebrates/chordata
A back-bone is present
Invertebrates/arthropods
No back-bone present
Examples of vertebrates
Fish, amphibians, reptiles, birds, mammals
Fish
- Cold-blooded aquatic animals
- Have gills, covered and protected by bony flap - operculum
- Body covered with scales
- Have fins to swim
- Eggs laid in water, external fertilization
Amphibians
- Cold-blooded animals
- Slimy, moist skin, no scales
- Eggs laid in water, external fertilization
- Adults mostly live on land, but lay eggs in water
- Eggs hatch into fish-like larvae that live in water
- Adults have lungs, larvae have gills
Reptiles
- Cold-blooded animals basking in sun to lower temperature
- Body covered in scales or plates to prevent water loss
- Breathing with lungs
- Four limbs or legs, each limb has 5 toes with claws
- Internal fertilization
- Can lay eggs on land
Birds
- Warm-blooded vertebrates adapted for flight
- Breathe with lungs
- Covered in feathers
- Streamlined shape for flying
- Have wings
- Feed with beaks
- Internal fertilization
Mammals
- Warm-blooded animals, breathe with lungs
- Seen on land and in water
- Body covered in fur or hair
- External pinna / ear
- Almost all give live birth
- Feed young with milk produced by mammary glands
Examples of invertebrates
Insects, arachnids, crustaceans, myriapods
Features of invertebrates
Have jointed legs, hard skeleton/exoskeleton, segmented bodies (head+thorax+abdomen)
Insects
- Largest group of arthropods
- Two pairs of wings (some have one)
- Large compound eyes
- Bodies covered in hard cuticle
Arachnids
- Two body parts
- No wings, no antennae
- Short chelicerae
- Pedipalps used for reproduction by males
- No compound eyes, multiple pairs of simple eyes
Crustaceans
- Two pairs of antennae sensitive to touch and chemicals
- Pair of compound eyes
- Legs on head for feeding
- Exoskeleton hardest of all arthropods
Myriapods
- Distinct head
- One pair of legs
- Body division not clear (thorax+abdomen)
- One pair of antennae
- Simple eyes
Bryophytes
small plants that have no vascular tissue for transport
Vascular plants
have vascular tissues
Ferns
-Have roots, stem, fronds (complex leaves)
- Leaves produce spores - germinate to grow new ferns
- Stem is below ground and grows horizontally, adventitious roots
Flowering plants
- Seeds are formed in flowers, enclosed and protected by fruits
- Embryonic leaf in the seed of a flowering plant is a cotyledon
Monocotyledons/Monocots
- Have on cotyledon
- Parallel veins
- Narrow and long leaves
- Vascular bundle scattered in the stem
- Fibrous roots
- Flowers in multiples of three
Dicotyledons/Dicots
- Have two cotyledons
- Network of veins
- Broad and short leaves
- Vascular bundle arranges in a ring in the stem
- Tap root
- Flowers in multiples of fours and fives
Heterotrophs
ingest food from other organisms
Autotrophs
makes their own food by photosynthesis
Saprotrophs
Digest food outside their bodies and absorb the substances formed
Unicellular organisms
Most protoctists (some are multicellular), yeast, prokaryotes
Viruses
- Not made of cells
- No cell membrane or cytoplasm
- Do not show 7 characteristics of life
- Protein coat surrounding genetic material
- Insert genetic material in a living cells, and uses materials of host to reproduce/make new virus
