Name:______Date:______Per:______

WS 6.1 - Plant Evolution

500-400 Million Years Ago

Graph the following Data in the correct color:

Year / % CO2 in Air
(Red) / % O2 in Air
(Blue) / Number of Spore Plant Species
(Green) / Number of Gymnosperms
Species
(Purple) / Number of Angiosperms
Species
(Orange)
500 / 49 / 14 / 0 / 0 / 0
490 / 48 / 14 / 0 / 0 / 0
480 / 46 / 14 / 0 / 0 / 0
470 / 44 / 14 / 0 / 0 / 0
460 / 42 / 14 / 0 / 0 / 0
450 / 41 / 14 / 0 / 0 / 0
440 / 38 / 15 / 0 / 0 / 0
430 / 36 / 17 / 0 / 0 / 0
420 / 34 / 19 / 0 / 0 / 0
410 / 32 / 20 / 0 / 0 / 0
400 / 30 / 22 / 30 / 0 / 0

Notes:

1.  There are 4 main types of plants of plants:


a.  Mosses
i.  Scientific name: Bryophyte
ii. Do mosses have vascular tissue?
NO
iii.  Do mosses produce spores or seeds?
NO /
b.  Ferns
i.  Scientific name: Seedless Vascular Plants or Ferns and fern allies)
ii. Do ferns have vascular tissue?
YES
iii.  Do ferns produce spores or seeds?
NO

c.  Cone Plants
i.  (Scientific name: Gymnosperms)
ii. Do cone plants have vascular tissue?
iii.  Do cone plants produce spores or seeds?
Seeds
iv.  What do cone plants produce seeds in?
`Cones /
d.  Flowering Plants
i.  (Scientific name: Angiosperms )
ii. Do flowering plants have vascular tissue?
iii.  Do flowering plants produce spores or seeds?
Seeds
iv.  What do flowering plants produce seeds in?
Fruit and flowers

2.  What was earth like before there was life?

  1. Earth consisted of just hot rock and water (No soil, and very little sediment)

3.  What was the air like before there was life?

  1. little oxygen
  2. lots of poisonous gasses in atmosphere
  3. No Ozone means lots of UV radiation

4.  What was the first life to form, and where did it first form?

  1. Bacteria began to fill the ocean because the water help shield organisms from the UV radiation
  2. There was purple bacteria on the surface and green bacteria deeper in the ocean
  3. The green bacteria became chloroplasts

5.  What was removing CO2 from the atmosphere before the first land plants?

  1. Bacteria in the ocean

6.  What were the bacteria doing in the ocean that removed CO2 from the atmosphere?

  1. Photosynthesis

7.  What type of plants where the first land plants?

  1. Bryophytes (mosses)

8.  Where did the first land plants from?

  1. Scotland

9.  Why did the first land plants need to form near water?

  1. The early plants lacked vascular tissue and roots, so they had no way to store or move water or nutrients within their body

10.  After bryophytes, what was the next group of plants to evolve?

  1. Ferns

11.  What adaptation allowed ferns to move further onto dry land?

  1. Roots

12.  What type of plants created the first soil?

  1. Ferns began to break earths rock up with the first roots

13.  Why did CO2 begin to drop when ferns began to take over land?

  1. Roots allowed plants to take over lots of unoccupied land, and so they spread quickly

14.  What did ferns evolve to cope with the dropping CO2 levels?

  1. The first leaves

15.  What type of plants became the first trees?

  1. Gymnosperms

16.  What happened to The O2 and CO2 levels once Gymnosperm trees came on earth?

  1. O2 went up and CO2 went down

17.  Why is this period known as the age of insects?

  1. Increase amount of O2 in the air cause insects to grow abnormally large

18.  What animals triggered the evolution of the first plant defenses like thorns and poison sap?

  1. Dinosaurs

19.  What did gymnosperms evolve to help get out of reach of large grazing dinosaurs?

  1. Wood to grow tall

20.  What adaptations made gymnosperms such successful plants?


Gymnosperms where the first plants that reproduced through pollination, so no water was needed / ` Gymnosperms where the first plants that reproduced through pollination, so no water was needed

21.  What advantages do seeds have over spores?

  1. Seeds have a protective shell and a food supply
  2. Cotyledon – The food supply of a seed
  3. The cotyledon feeds to embryo slowly, so the seed doesn’t have to germinate until all the conditions are just right

22.  What 3 adaptations allowed flowering plants to take over the planet so much faster than other plants had up to that point?

  1. Flowers allowed plants to reproduce faster and more efficiently
  2. A shorter life cycle allowed flowering plants evolved faster
  3. Seeds had their on food storage (cotyledons) that allowed for longer dormancy

23.  What organisms pollenated the first flowers?

  1. Beatles

24.  Why did white flowers stand out so much in that world?

  1. Because the world was full of only green leaves

25.  What did flowers evolve to attract insects pollinators and triggered the evolution of bees?

  1. Nectar

26.  How does nectar triggering the growth of populations of insects also cause the population growth of birds and larger carnivores?

  1. More insects means more food for birds and larger carnivores

Use the graph to fill in the Milestone events from this time period:

How do we know that dinosaurs started eating grass just 66 million years ago?

  1. We found it in their poop

27.  What caused the largest mass extinction event to ever happen on the planet?

  1. A meteorite

28.  What allowed mammals to survive the meteorite?

  1. They burrowed

1.  What are angiosperms?

a.  Angiosperms – A plant that has vascular tissue and produces seeds in flowers

b.  Flower – The reproductive structure of an angiosperm

c.  Fruit – a plant ovary that helps spread plant seeds

2.  Why are there more angiosperms than any organism on earth?

a.  Angiosperms where the first plants to make a flowers and seeds in fruit

3.  What are the advantages of angiosperm reproduction?

a.  Flowers Have male and female so they can reproduce sexually or asexually

b.  Attract an individual animal pollinators is more reliable than using the wind

c.  Faster life cycle means more evolution in a shorter time

d.  Fruit helped spread seeds so the baby plants didn’t compete with the parent

4.  What are the different ways flowering plants are classified?

a.  Flowering plants are most commonly divided into two main groups, monocots Eudicots (dicots)

5.  What are the characteristics of monocots and dicots?

Monocot seeds don’t split in half. (there is only one cotyledon) / Dicot seeds split in half. (there is 2 cotyledons)

______Mono______Di______Di______
Monocot flowers have petals in multiples of 3 / Dicot flowers have petals in multiples of 4 or 5

______Mono______Di______Mono______
Monocot stems have no rings of vascular tissue / Dicot stems have rings of vascular tissue

______Di______Mono______Di______
Monocots roots are a bunch of strings (fibrous root) / Dicot have one centralized root (tap root)

______Mono______Di______Di______
Monocots have parallel vanes in leaves / Dicots have branched vanes in the leaves

______Mono______Di______Mono______

29.  Why did grasses (monocots) survive the meteorite?

  1. Their growth centers are below ground not in the air so when grazers eat them they can regrow. This kept them away from the heat of the meteorite

30.  How did baud leaf plants (Dicots) survive the meteorite?

  1. They had seeds in the ground

31.  What removed all the CO2 from the air after the meteorite hit?

e.  The building of the Himalayas locked all the CO2 away in rock (limestone)

32.  Why did grasses (monocots) survive a low CO2 environment better than Braud leaf plants (dicots)?

  1. Grasses have bundle cells which inject CO2 directly into the leaf

33.  Why did the first fruit start evolving after the meteorite hit?

  1. To attract mammals, there were no more dinosaurs left

34.  What traits did the fruit have that appealed just to mammals?

  1. Peels (because mammals had hands)
  2. Turned red when ripe to appeal to our color vision

35.  Why did humans evolve to stand on 2 legs?

  1. In a world filled by grass after the meteorite, our ancestors started standing on 2 legs to look over tall grass for danger