Which group of plants common during the triassic period had seeds lacking a protective outer coat?

The most dominant form of plants found in Triassic Era was Gymnosperms. They lack a protective covering on seed and did not produce flower. The outer coating of seed is absent in Gymnosperms. There were no angiosperm in that era and the dominant form was angiosperm only. This was because of the climatic conditions at that time that the survival of any other plants other than gymnosperm was not possible.

1) gene flow

- it is described as the transfer of genes from one population to another population so that frequency of gene is increased.

-a zebra migrates to join a different herd of zebras.

2) natural selection

- a mechanism of evolutionary change in which individuals with advantageous traits survive and reproduce whereas the others ( those that can not adapt) eliminate from the population.

-competition for sunlight leads to taller trees.

3) mutation

- permanent change in the nucleotide sequence of dna ( genetic material) that could have harmful or useful consequences.

-the dna of a snake changes to make its venom stronger.

4) genetic drift - it is a random phenomenon ( that occurs by chance such as fire) that results in change in the gene frequency in a small population.    

-a grassfire randomly sweeps through a population of buffalo and kills most of the animals.

explanation: