Plant Biodiversity

Question 1

what are charophyceans?

Answer 1

closest algal relatives to plants

Question 2

what is the advantage of sporopollenin?

Answer 2

prevents exposed zygotes from drying out so aided in the evolution of land plants

Question 3

what is the monophyletic group name of land plants?

Answer 3

embryophytes

Question 4

how many times did embryophytes evolve and what from?

Answer 4

the evolved only once and from freshwater aquatic multicellular algae

Question 5

what are 4 traits shared between land plants and charophyceans?

Answer 5

1) rose shaped complexes for cellulose synthesis
2) peroxisome enzymes
3) structure of flagellated sperm
4) formation of phragmoplast in cytokinesis

Question 6

what are 5 problems with moving from aquatic habitats to land?

Answer 6

1) water balance
2) availability of nutrients and gases
3) support
4) UV protection
5) reproductive strategy

Question 7

what are the 2 main clades of land plants?

Answer 7

1) bryophytes

2) tracheophytes

Question 8

what are features of bryophytes?

Answer 8

• non vascular plants

- gametophyte dominant

Question 9

what are features of tracheophytes?

Answer 9

• vascular plants

- sporophyte dominant

Question 10

3 non vascular plants?

Answer 10

1) liverworts
2) mosses
3) hornworts

Question 11

3 types of vascular plants groups?

Answer 11

1) free sporing plants
2) angiosperms - flower seed plants
3) gymnosperms - seed plants

Question 12

what are apical meristems?

Answer 12

localised regions of cell division - help growth of root and stems

Question 13

explain alternation of generations?

Answer 13

multicellular haploid (gametophyte dominant) and multicellular diploid (sporophyte dominant) stages of the lifecycle

Question 14

what is the job of the sporangium?

Answer 14

protects developing spores from harm

Question 15

what are the male and female reproductive organs called?

Answer 15

1) archegonia - female

2) antheridia - male

Question 16

why are land plants called embryophytes?

Answer 16

they have multicellular dependent embryos with placental cells that transfer nutrients from parent to embryo

Question 17

what are bryophytes reproductive strategy?

Answer 17

they are homosporous

Question 18

what are the 2 main things which make up a bryophyte gametophyte and how are they anchored?

Answer 18

1) gametophore
2) protonema
anchored by rhizoids

Question 19

what does a bryophyte sporophyte consist of and what are their jobs?

Answer 19

1) a foot - absorbs nutrients from parental gametophytes
2) a seta - conducts materials to sporangium
3) a sporangium - produces spores by meiosis

Question 20

what is a calyptra?

Answer 20

protective cap for sporangium which is shed when sporangium is mature

Question 21

what is a peristome and its job?

Answer 21

tooth like structures for gradual spore discharge

Question 22

which sporophytes have stomata for gas exchange?

Answer 22

mosses and hornworts

Question 23

what are isospores?

Answer 23

spore exhibiting no sexual dimorphism

Question 24

how are mosses able to live in extreme habitats?

Answer 24

they can survive loss of most of their body water and rehydrate when water is available so can live in cold or dry habitats

Question 25

what is the benefit of phenolic compounds in mosses cell walls?

Answer 25

absorb damaging levels of radiation

Question 26

how do peat bogs prevent decay and what do they store?

Answer 26

low nutrients and temperatures and they store organic carbon

Question 27

what are the most primitive extant vascular plants?

Answer 27

lycopsids

Question 28

why are tracheophytes more adapted for life on land than bryophytes?

Answer 28

because the sporophyte stage is dominant over gametophyte stage and sporophyte has lignified conducting tissues providing support

Question 29

are lycopsids homosporous or heterosporous?

Answer 29

both

Question 30

what is the job of the xylem and phloem?

Answer 30

xylem conducts most of the water and minerals | phloem has living sugar conducting cells and transports amino acids

Question 31

what are tracheids?

Answer 31

tube shaped cells that carry water and minerals up from the roots

Question 32

what are the 2 most abundant polymers in plants?

Answer 32

1) cellulose | 2) lignin

Question 33

what is the difference between microphyll and megaphyll leaves ?

Answer 33

microphylls - spine shaped leaves with single veins | megaphylls - highly branched vascular system with much greater photosynthetic activity

Question 34

what are sporophylls?

Answer 34

modified leaves that bear sporangia

Question 35

what is an advantage of heterosporous plants?

Answer 35

due to the megaspore and sperm needing to land near each other which has low probability it encourages outbreeding which speeds up evolution and it doesn't need damp to reproduce so opens up more land habitats

Question 36

what are 4 points of significance of seedless vascular plants?

Answer 36

1) formed first forests in carboniferous period 2) increased photosynthesis = removal of CO2 = global cooling 3) formed peat bogs which drove the industrial revolution and ice age world into greenhouse world 4) end or permian arborescent lycopsids became extinct leaving herbaceous forms present today