Question

Q1:Which three evolutionary innovations are present in land plants (but not all land plants) that allowed them to live on land ? Explain why each trait was important in the transit ion to life on land and which kind of plants will find them ?

Q2: What term describes traits that are common to all members within a clade? If all members of a clade exhibit these traits, when did the traits evolve?



Q3: Name the algal group that are the closely living relatives to land plants. What is the name of the life cycle they exhibit.




Q4: Plants and this algal group share the trait of cellulose-rich cell walls. Does this change your answer to when this trait evolved? Explain your reasoning.




Q5: Draw a simple phylogenetic tree showing: i. the most recent common ancestor of plants and the algal group identified in Question 2; ii. two branches showing these two groups; and iii. a line mapping the origin of the alternation of generations in the phylogeny.

Answer 1

1. Three evolutionary innovations in land plants are as follows:

a) The development of alternation of generation is a characteristic feature that includes a cycle of haploid and diploid life forms in a plants life cycle. This helps the plant in its survival based on the types of lifeforms that get more adapted to the environment.This type of alternation is found in a plant type called pteridophytes.

b) The development of vascular tissues that are the main tissues in a land plant are responsible for long distance transport in the plant. These type of tissues are found in angiosperms.

c) The development of dry seeds help land plants in the easy dispersal of seeds through air. This helps in spreading the range of the plant. A plant type the has this type of seeds is pteridophytes.