The Living World 8th Edition by George Johnson

تمرين 8

The biological species concept does not work as well for plants as for animals because
A) strong barriers to hybridization exist among most plants.
B) outcrossing is not common among animals.
C) asexual reproduction is rare in plants.
D) many plants do not regularly outcross.
The number of named species is about
A) 1.5 billion.
B) 15 million.
C) 150 million.
D) 1.5 million.