Characteristics of life
●
Movement
○
●
Respiration
○
●
The ability to produce other living organisms of the same kind
Excretion
○
●
It is the ability of living organisms to irreversible increase in size and volume
Reproduction
○
●
A living organisms respond to stimuli
Growth
○
●
It is the chemical process by which glucose molecules breakdown to release energy
Sensitivity
○
●
It is the change in direction/position
The ability to remove metabolic waste products from the body
Nutrition
○
It is the supply of food required by living organisms to stay alive
●
Glucose + oxygen → Carbon dioxide + water + energy
●
Autotrophic
○
●
An organism which produces its own food for example green plants
Heterotrophic
○
Cannot make their own food so get their nutrition by ready-made organic
compounds(animals/fruits)
Classification
●
●
Plants
○
They are multicellular
○
Cells have a nucleus and contain chloroplasts
○
Carry out processes like photosynthesis and therefore make their own food(autotrophic)
○
Have cell walls made of cellulose
○
Store sugar as starch
○
They show movement but cannot locomote
Animals
○
They are multicellular
○
Get their nutrition from feeding on other organisms(heterotrophic)
○
They are capable of movement and locomotion
○
Store sugar in the form of glycogen
○
Cells have nucleus
○
No cell wall or chloroplast
●
●
●
Fungi
○
Can be multicellular or unicellular
○
Have many nucleus(nuclei) and do not have chloroplast
○
Have cell walls made of chitin
○
Made of a network of fibres called a mycelium of hyphae
○
Feed by saprophytic nutrition(absorbs the food) using extracellular enzymes
Protoctists
○
Multicellular or unicellular but mostly unicellular
○
Cells have nucleus
○
May or may not have cell wall and chloroplast
○
They are either heterotrophic or autotrophic
○
E.g Protozoa like amoeba or algae
○
Knows as Dustbin kingdom
Bacteria/Prokaryotes
○
Small single celled organisms
○
3 basic shapes- spheres, rods and spirals
○
Cell wall made of polysaccharides and proteins(peptidoglycan)
○
Some have a capsule or slime layer
○
Has primitive nucleus(not a proper nucleus-no nuclear membrane- contents of nucleus flows
freely in cytoplasm)
●
○
Cell walls are made of cellulose and they don't have mitochondria
○
Some species have flagella(locomotory organ)
○
Some contain plasmids(loops of DNA) which we can use in genetic engineering
Viruses
○
All are parasites
○
Much smaller than bacteria cells
○
Not made of cells and do not carry out the normal characteristics of living organisms
○
Made of genetic material surrounded by a protein coat
○
All natural viruses cause disease
Classifying animals
●
Binomial naming system
○
International naming system where the name of the
organism consists of 2 parts
○
Binomial naming system is written in italics where the first
letter is the genus and is capital and the second word is
species where all letters are small.
○
Wolf is Canis lupus, Canis being the genus and lupus being a species
Kingdom
Animal
Animal
Phylum
Arthropods
Vertebrates
Class
Insects
Mammals
Order
Lepidoptera(butterflies,moths)
Pholidota
Family
Danaidae
Manidae
Genus
Danus
Manis
Species
Danaus plexippus
Manis gigantea
Phylum Vertebrates
Animals which have a backbone
●
●
●
●
●
Fish
○
Vertebrates with scaly skin
○
Have gills
○
Have fins
Class Amphibians
○
Vertebrates with moist scale-less skin
○
Eggs laid in water, larva(tadpole) lives in water
○
Adult often lives on land
○
Larva has gills, adult has lungs
Class Reptiles
○
Vertebrates with scaly skin
○
Lay eggs with rubbery shells
Class Birds
○
Vertebrates with feathers
○
Heart has 4 chambers
○
Endothermic
○
Lay eggs with hard shells
Class Mammals
○
Vertebrates with hair
○
Have a placenta
○
Endothermic
○
Have diaphragm
●
○
4 heart chambers
○
Have different type of teeth
Bacterial cell
○
Often unicellular
○
Have no nucleus
○
Have cell walls, not made of cellulose
○
Have no mitochondria
Phylum Arthropods
Several pairs of jointed legs
Have exoskeleton
●
●
●
●
●
●
Insects
○
Arthropods with 3 pairs of jointed legs
○
2 pairs of wings
○
Breathe through trachea
○
Head, thorax and abdomen
Crustaceans
○
Arthropods with more than 4 pair of jointed legs
○
Not millepied or centipedes
○
Breathe through gills
Arachnids
○
Arthropods with 4 pairs of jointed legs
○
Breathe through gills called book lungs
Myriapods
○
Body consists of many segments
○
Each segment has jointed legs
Ferns
○
Plants with roots, stems and leaves
○
Have leaves called fronds
○
Do not produce flowers
○
Reproduce by spores
Flowering plants
○
Plants with roots, stems and leaves
○
Reproduce sexually by means of flower and seeds
○
Seeds are produced inside the ovary, in the flower
Monocots
Dicots
Monocots have 1 cotyledon
Dicots have 2 cotyledons
Petals are arranged in multiples of 3
Petals are arranged in multiples of 4 or 5
Secondary growth is absent
Secondary growth is present
Fibrous roots
Tap roots
Veins parallel to the midrib
Dicots not parallel
Leaves are slender
Leaves are broad
Have scattered vascular bundle
Dicots have ring shaped
Have 1 pore in the pollen grain
Have 3 pores in the pollen grain
Stems in monocots are non-woody
Dicots are woody and branched
Procaryotes
Fungi
Single-celled
Multi-celled
No nucleus
Nucleus present
No organelles
Have organelles
Need host to grow
Grow on their own
Simple cell structure
Complex cell structure
Plants
Animals
Cannot locomote
Can locomote
Contains cell wall
Doesn’t have cell wall
Autotrophic
Heterotrophic
Store sugar as starch
Store sugar as glycogen
Insects
Crustaceans
3 pair of jointed legs
4 pairs of jointed legs
Breathe through trachea
Breathe through gills
2 pair of wings
No wings
Amphibians
Reptiles
Moist scale-less skin
Scaly skin
Breathe through both gills and lungs
Lay eggs in water, covered in gel
Breathe only through lungs
Lay eggs on land where they have hard protective
shell