Adaptations and innovation of land plants - Week 16

Question 1

Seed plants are called what?

Answer 1

Spermatophytes

Question 2

Spermatophytes are split into 2 catagories, what are they?

Answer 2

Gymnosperms - seed-producing w no flowers

Angiosperm - seed-producing w flowers

Question 3

What is homospory?

Answer 3

Produce one type of spore/ gametophyte

example: bryophytes

Question 4

What is anisospory?

Answer 4

Large and small spores in sporangiu,

Example: extinct barinophyton

Question 5

What is Heterspory?

Answer 5

Produces two types of spores/ gametophyte

Example; all seed plants, spermatophytes

Question 6

How did the sporophyte develop with:

The megapores

The microspores

Answer 6

Megaspore - megasporangia - megasporophylls - megagamtophytes (female)

Microspores - microsporangia - microsporophylls - microgametaphytes (male)

Question 7

Heterospory originated 4 times in different groups, why?

Answer 7

• resource allocation
• increased potential for outbreeding (heterosis)
• protection of gamtophytes (endosporic development)

Question 8

Is the evolution of heterospory analogous to evolution of oogamy ?

Answer 8

Yeh man

Question 9

If megaspore is not released what happens?

Answer 9

Germinates in the sporophyte, produces female megagametophyte, essentially acting as ovule

Question 10

Seeds evolved in a line of what?

Answer 10

Heterosporous progymnosperms that retained their megaspores on the sporophyte

Question 11

Each megasporagium produces one megaspore, what happens to the others?

Answer 11

the other 2 degenerate

Question 12

What are some qualities of seed plants - spermatophytes?

Answer 12

• Do not shed megaspores, one megaspre per megasporangium
• Germinates then megagamtophyte in situ
• in enclosed ovule structure
• microspores, pollen, contain microgametophytes, pollen grain

Question 13

What are the benifits of retaining the megaspores (seed habit)

Answer 13

• reduces requirement of water to fertilize eggs
• protection of female gametophyte and embryo sporophyte
• Nourishment of female gametophyte and embryo sporophyte

Question 14

When do first seed plants appear?

Answer 14

Carboniferous spore tree, 350 mya, pteridospersm

Question 15

In early permian 300 mya gynosperms increase into new groups:

Answer 15

cycads, ginkgos,

Question 16

Climate change caused wide spread aridity thru continent, how did this effect seed plants?

Answer 16

Seed plants better adapted to arid conditions

Question 17

What are conifers reproductive structure?

Answer 17

Cones

Question 18

8 families of conifers?

Answer 18

good luck mate

Question 19

Characteristics of conifers?

Answer 19

• all arborescent
• pollen produces tube to deliver non-motile sperms to ovule
• Pollen consists of 3 cells: tube, stalk, body cell

Question 20

What is pyrisecence?

Answer 20

Fire stimulated seed dispersal of pine cone (fire melt resin)

Question 21

What are the Gnetales?

Answer 21

• advanced gynosperms
• many same features as flowing plants
• convergent evolution with: xylem containing vessel, insect-pollinated etc

Question 22

How do heterosporous microspores and megaspores develop?

Answer 22

Microspores develop into pollen

megaspores develops into female gametophyte enclosed in ovule

Question 23

Closest known relative of angiospersm?

Answer 23

gymnosperm? Not currently known, fossil record missing

Question 24

Evolutions of the carpel?

Answer 24

• No archegonia housing egg, highly reduced 7/8 cells

- Hypothesised carpel is just folded over leaf, like all structure in flower (stamen for example)

Question 25

What evolved to attach to animals for seed transportation ?

Answer 25

Angiosperm male gametophyte

Question 26

Fertilization in angiosperms

Answer 26

Flowering plants usually cause double fertilization

Question 27

Angiosperm key innovation: Endosperm?

Answer 27

- Resources are only laid down in ovule/ seed after fertilization - angiosperm seeds utilize material resources more efficiently than gymnosperm seeds, much smaller

Question 28

What did fruit evolve?

Answer 28

The structure formed from parts of the flowers of inflorescence contains seeds adaptation of seed dispersal by animals

Question 29

How are angiosperms split up?

Answer 29

Dicotyledon, dicots Monocotyledon, monocots

Question 30

Characteristics of Dicots Monocots

Answer 30

dicots: embryonic plant w 2 seed leaves, flower parts usually in 5/4 multiples monocots: embryonic plant w 1 seed leaf, flower parts in 3 multiples

Question 31

How are most flowers adapted to pollinate?

Answer 31

- By animals | - Some flowers so specialised they can only be pollinated by a single insect species

Question 32

What are primary attractants (rewards) for pollinators?

Answer 32

-pollen, nectar, oil, protection and broad place, sexual attraction

Question 33

What are secondary attractants (rewards) for pollinators?

Answer 33

odure, visual attraction, temperature, motion

Question 34

What are hermaphrodite flowers?

Answer 34

Co-sexual, flowers unique to cross pollination by flowers, | Can lead to self- inbreeding depression

Question 35

``` Adaptation to avoid self-fertilisation? Dichogamy Herkogamy Dicling Self-incompatibility ```

Answer 35

Dichogamy: Separation of sexual organs in time Herkogamy: separation of sexual organs in space Dicling: sexual polymorphism, plants male or female Self-incompatibility: plants able to recognise n reject own pollen