Bryophytes were the dominant plants in the first 100 million years of plant evolution. By the Carboniferous period, seedless vascular plants formed giant forests. Why were these plants able to outcompete bryophytes?
a. Their vascular tissue allowed them to grow tall, competing for light and more widely dispersing their spores.
b. Their protected embryos were better able to withstand dry conditions, providing a selective advantage in dominating terrestrial habitats.
c. They did not require water for their sperm to swim to fertilize the eggs, allowing them to colonize dry habitats.
d. They were diploid, so they could grow faster and taller than haploid bryophytes.
e. They had megaspores and microspores. This extra genetic variation enabled natural selection to favor taller growth.
Answer: a. Their vascular tissue allowed them to grow tall, competing for light and more widely dispersing their spores.
You might also like to view...
The disease known as severe acute respiratory syndrome (SARS) is caused by a type of:
A) coronavirus B) herpes virus C) papillomavirus D) picornavirus
A mutualistic symbiosis where fungal hyphae grow between and around plant roots but do not
penetrate plant root cells is called a(n) ____.
a. ectomycorrhiza b. lichen c. arbuscule d. endomycorrhiza e. haustorium
Four of the five answers listed below are barriers to pathogen invasion. Select the exception
a. intact skin b. mucous membrane c. gastric juices d. blood plasma e. lysozyme
Most human adults are lactose intolerant. People with lactose intolerance produce insufficient amounts of _______.
A. vitamins B. lactose C. saliva D. the enzyme lactase