Lecture 28 - Plants II

Question 1

How did seeds change the course of plant evolution?

Answer 1

enabled bearers to become the dominant producers in most terrestrial ecosystems

Question 2

What is a seed?

Answer 2

consists of a an embryo and nutrients surrounded by a protective coat

Question 3

What else are common to seed plants? (5 derived traits of seed plants)

Answer 3

1. reduced gametophytes
2. heterospory
3. ovules
4. pollen

Question 4

What does reduced gametophytes mean?

Answer 4

microscopic male + female gametophytes nourished + protected by sporophyte (2n)

Question 5

What does heterospory mean?

Answer 5

• microspore (gives rise to male gametophyte)

- megaspore (gives rise to a female gametophyte)

Question 6

What is pollen?

Answer 6

pollen grains make water unnecessary for fertilization

Question 7

What is a characteristic of seeds?

Answer 7

• survive better than unprotected spores

- can be transported long distances

Question 8

ancestors of seed plants likely ______ while seed plants are _______

Answer 8

-homosporous, hetersporous

Question 9

What produced megaspores?

Answer 9

megasporangia

Question 10

What produces microspores?

Answer 10

microsporangia

Question 11

What is an ovule?

Answer 11

consists of a megasporanium, megaspore, one or more protective integuments

Question 12

How many integuments does gymnosperm megasporangia have?

Answer 12

one

Question 13

How many integuments does angiosperm megasporangia have?

Answer 13

two

Question 14

What do microspores develop into?

Answer 14

pollen grains

Question 15

What are pollen grains?

Answer 15

contain the male gametophytes