All living organisms are linked to one another because
1. They have common genetic material of the same type
2. They share common genetic material but to varying degrees
3. All have common cellular organization
4. All of the above
The number of species that are known and described ranges between:
1. | 1.2 and 1.3 million | 2. | 1.4 and 1.5 million |
3. | 1.7 and 1.8 million | 4. | 2.1 and 2.2 million |