Ch 30 Seed Evolution in Gymnosperms Flashcards Preview

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Flashcards in Ch 30 Seed Evolution in Gymnosperms Deck (31):
1

Seed

Consists of an embryo and nutrients

2

What surrounds the seed?

A protective seed coat

3

Why are plant seeds an advance in the evolution of life on land?

They enabled the plants that possessed them to become the dominant producers in most terrestrial ecosystems

4

In addition to seeds, the following are common to all seed plants:

1) Reduced gametophyte
2) Heterospory
3) Ovules
4) Pollen

5

In nonvascular plants, what is the dominant free-living stage?

The gametophyte

6

In seedless vascular plants, what is the dominant free-living stage?

The sporophyte

7

What is true of the gametophytes of seed plants?

They develop within the walls of the spores and are retained within tissues of the sporophyte

8

The ancestors of seed plants were likely homosporous or heterosporous?

Homosporous

9

Homosporous

Possessing one type of sporangia

10

Seed plants are homosporous or heterosporous?

Heterosporous

11

Heterosporous

Possessing male and female sporangia

12

Megasporangia

Produce megaspores

13

Megaspores

Give rise to the female gametophyte (produces eggs)

14

Microsporangia

Produce microscopes

15

Microspores

Give rise to the male gametophyte (pollen grains)

16

An ovule consists of:

1) Megasporangium
2) Megaspore
3) One or more protective integuments

17

What occurs once a pollen grain reaches the ovule?

It extends a pollen tube that discharges sperm into the female gametophyte within the ovule

18

Advantages of seeds over spores:

1) Can remain dormant for days to years until conditions are favorable for germination

2) Have supply of stored food

3) May be transported long distances by wind or animals

19

Two groups of seed plants:

1) Gymnosperms
2) Angiosperms

20

Gymnosperms

Seeds are exposed on groups of sporangia that form cones

21

Angiosperms

Flowering plants with seeds within fruits

22

Four phyla of gymnosperms

1) Cycadophyta
2) Ginkophyta
3) Gnetophyta
4) Coniferophyta

23

Phylum Cycadophyta

Cycads

24

Phylum Ginkophyta

One living species, Ginko biloba

25

Phylum Genetophyta

Gnetum, Ephedra, and Welwitschia

26

Phylum Coniferophyta

Conifers (pine, fir, redwood, etc.)

27

Cycad cones

Have large cones

28

Cycad leaves

Palm-like leaves

29

Are cycads palms?

NO! Palms are angiosperms and cycads are gymnosperms

30

What is the largest gymnosperm phyla?

Conifers

31

During what part of the year do conifers carry out photosynthesis?

All year round because they do not lose their needles