Understanding Genus and Species

Every living organism has a two-part scientific name:

Official Rules for Writing Scientific Names:
  • Genus name is written first
  • Genus starts with a capital letter
  • Species name is written second
  • Species starts with a small letter
  • Both words are written in italics
  • Example: Homo sapiens
First word → Genus
Second word → Species

What is Genus?

Genus is a group of closely related species that share common characteristics.

Examples:
  • Panthera → Lion, Tiger
  • Canis → Dog, Wolf
  • Homo → Human
Genus
= Group of species

What is Species?

Species is the smallest unit of classification. Members can interbreed and produce fertile offspring.

Examples:
  • sapiens → Human
  • leo → Lion
  • tigris → Tiger
Species
= One kind

Genus vs Species – Quick Comparison

Feature Genus Species
Position First word Second word
Capital letter? Yes No
Example Homo sapiens
Can be used alone? Yes No
Number of types Many species Only one type
Breed & get babies? Sometimes (infertile) Always (fertile)

Human

Human

Genus: Homo

Species: sapiens

Full Name: Homo sapiens

Lion

Lion

Genus: Panthera

Species: leo

Full Name: Panthera leo

Tiger

Tiger

Genus: Panthera

Species: tigris

Full Name: Panthera tigris

Dog

Dog

Genus: Canis

Species: familiaris

Full Name: Canis familiaris

Mustard

Mustard

Genus: Brassica

Species: campestris

Full Name: Brassica campestris

Pea

Pea

Genus: Pisum

Species: sativum

Full Name: Pisum sativum

Maize

Maize

Genus: Zea

Species: mays

Full Name: Zea mays

Potato

Potato

Genus: Solanum

Species: tuberosum

Full Name: Solanum tuberosum

Quiz - Questions

Score: 0/0