1.3

Features of Organisms

1) Animals – Eukaryotes

●     Cells have a nucleus

●     No cell wall or chloroplasts

●     Feed on organic substances made by other organisms.

 → Carbon-containing compounds (e.g., meat, plants)

2) Plants – Eukaryotes (cell walls made of cellulose)

●     Cells have a nucleus, a cell wall, and chloroplasts

●     Fed by photosynthesis

●     Most have roots, stems, and leaves.

●     All contain chlorophyll

3) Fungi – Eukaryotes (cell walls not made of cellulose)

●   Cells have a nucleus and cell walls

●     No chlorophyll

●     Obtain nutrition saprophytically or parasitically.

 → Break down and digest organic matter using enzymes, then absorb it

●     Act as decomposers

●     Usually multicellular (e.g., yeast is unicellular)

●     Made up of threads called hyphae

●     Reproduce using spores (not exclusive to fungi)

4) Protoctists – Eukaryotes

●     Both unicellular and multicellular

●     Feed saprotrophically or by photosynthesis.

●     Have a nucleus

●     May have a cell wall and chloroplasts

5) Prokaryotes – Prokaryotic (e.g., Bacteria)

●     No nucleus or mitochondria

●     Usually unicellular

●     Free strands of DNA

●     Cell wall present (not cellulose)

●     Often contain plasmids

Groups within the Animal Kingdom (Vertebrates)

Vertebrates: Animals with a backbone

1) Fish

●     Live in water

●     Scaly skin

●     Gills and fins

●     Eggs have no shell (laid in water)

2) Amphibians (e.g., toads, salamanders)

●     Live on land and water

●     Young undergoes metamorphosis (tadpole → adult)

●     Moist skin without scales

●     Eggs without shells (laid in water)

●     Tadpoles have gills; adults have lungs.

3) Reptiles (e.g., crocodiles, lizards, snakes)

●     Scaly skin

●     Lay soft-shelled eggs on land

4) Birds

●     Feathers (scales on legs)

●     Beaks

●     Lay hard-shelled eggs

●     Only two legs

5) Mammals

●     Hair or fur

● Females have mammary glands.

●     Young develops inside the uterus, connected by the placenta

●     Live birth

●     Various types of teeth

●     Sweat glands

●     Diaphragm

●     Pinna (external ear flap)

Written by Sahana Venkat