The evolution of plants

Question 1

How many species of plants are described?

Answer 1

Roughly 320,000

Question 2

In the colonization of land of plants, what were some problems they had to overcome?(4)

Answer 2

1. It was a drier environment
2. There is a strong effect of gravity
3. There are no nutrients in the atmosphere
4. There are more rapid changes in temperature.

Question 3

What were some advantages of the colonization of land by plants? (3)

Answer 3

1. There is brighter sunlight that isn’t blocked by water and phytoplankton.
2. There is more CO2 in the atmosphere.
3. There are an abundance of nutrients on the shoreline.

Question 4

Name 3 large adaptations that let plants colonize land.

Answer 4

1. The protection of spores/gametes/zygote/embryo
2. Maximizing photosynthesis
3. Growth to compensate for lack of movement

Question 5

In the life cycle of a plant, what is another name for the haplodiplontic cycle?

Answer 5

The Alteration of Generations

Question 6

What is the multicellular 2n (diploid zygote) organism called in the life cycle of a plant?

Answer 6

The sporophyte

Question 7

What is the multicellular n(haploid gamete) organism called in the life cycle of a plant?

Answer 7

The gametophyte

Question 8

What is the purpose of the maternal gametophyte tissues?

Answer 8

They house the embryo and protect it and give it nutrients.

Question 9

What are the spore walls made of?

Answer 9

A highly resistant polymer called sporopollenin.

Question 10

Where does spore dispersion happen?

Answer 10

In the air.

Question 11

What is the stem cell region at the ends of the roots and tips of a plant called?

Answer 11

The apical meristem.

Question 12

What kind of growth happens at the apical meristem?

Answer 12

Indeterminate growth.

Question 13

What is the role of the cuticle in a plant?

Answer 13

it protects against desiccation (loss of water)

Question 14

What is the role of stomata?

Answer 14

They are pores surrounded by guard cells that allows for gas exchange and water loss regulation.

Question 15

What is a bryophyte?

Answer 15

It is a paraphyletic group of plants that are non-vascular and don’t produce seeds or flowers. They are the oldest group and consist of liverworts, mosses, and hornworts.

Question 16

Describe the life cycle of a bryophyte

Answer 16

It is haplodiplontic and gamete dominated. Spore germination depends on water.

Question 17

What are rhizoids?

Answer 17

Filaments on bryophytes that attach to substrate.

Question 18

What is the monophyletic group of plants that isn’t bryophytes?

Answer 18

Tracheophytes

Question 19

What is the defining feature or tracheophytes?

Answer 19

The sporophyte is larger, and the gametophyte is reduced in size.

Question 20

What does it mean for a plant to be vascularized?

Answer 20

It is a tracheophyte and has lignified (woody) tissue that transport waters and sugars.

Question 21

What does the xylem transport?

Answer 21

Water and minerals

Question 22

What does the phloem transport?

Answer 22

It transports sugars.

Question 23

What is lignin?

Answer 23

It is the polymer in cell walls that makes things woody, it is good for support and it is water impermeable.

Question 24

What is it called when there is one type of leaf that produces a bisexual gamete? What plants is this common in?

Answer 24

The plant is homosporous. This is common in most seedless vascular plants.

Question 25

What plants produce a male and female gamete? What plants does this happen in?

Answer 25

Heterosporous plants do this. This happens in seeding plants.

Question 26

What are the advantages of heterospory?

Answer 26

1. Each spore has specific selection with specific functions. 2. A female gametophyte can better nourish the embryo. 3. There is a higher genetic diversity because there is no self-fertilization because males and females can mature at different times.

Question 27

What is the newest paraphyletic group of plants?

Answer 27

Spermatophytes (seeding plants)

Question 28

What is a seed?

Answer 28

It is an embryo surrounded by nutritious substances and a protective coat.

Question 29

What are the 5 key innovations of seed plants?

Answer 29

1. reduced (smaller) gametophytes is protected from environmental stresses, UV desiccation, and is directly nourished from the sporophyte. 2. The Ovule (attached to the sporophyte) contains the megaspore, and allows for fertilization without water. 3. Seed plants are heterosporous, there is a female and male spore. 4.Microspores are enclosed within a pollen wall and can disperse very far. 5. The production of a seed means the embryo is nourished and can resist drought/temperatures. Seeds can germinate under favorable conditions.

Question 30

What is another name for a male spore?

Answer 30

A microspore.

Question 31

What is another name for a female spore?

Answer 31

A megaspore.

Question 32

What is a gymnosperm?

Answer 32

It produces seeds, but no flowers.

Question 33

Why did gymnosperms adapt?

Answer 33

They evolved as the climate became dryer.

Question 34

What is an angiosperm?

Answer 34

It is a seeding plant that flowers. They make up more than 90% of all living plant species.

Question 35

What happens to the seed enclosure in an angiosperm?

Answer 35

The seed stays in a carpel that turns into a fruit.

Question 36

What are the two parts of a flower, and what do they produce?

Answer 36

The carpel produces the female gametophyte, and the stamen produces the male gametophyte.

Question 37

What is the fruit?

Answer 37

The mature ovary of a flower that help with seed dispersal.

Question 38

What is the name of wind dispersal of seeds?

Answer 38

Anemochory

Question 39

What is the name of animal dispersal of seeds?

Answer 39

Zoochory

Question 40

Does flower pollination depend on water?

Answer 40

No it has non-motile sperm.

Question 41

What is the difference between an ovary and an ovule.

Answer 41

An ovule matures into a seed where an ovary matures into a fruit.

Question 42

What is cross pollination?

Answer 42

The pollination between different plants.

Question 43

Describe the fertilization process of pollen/eggs.

Answer 43

There is a double fertilization, one sperm cell creates a zygote with the egg, and the other sperm cell fuses with the central cell endosperm tissue that nourishes the embryo.