Topic 9,10:land plants and seed-plants

Question 1

plant kingdom characteristics

Answer 1

-terrestrial and some have returned to aquatic habitats
-they are eukaryotes
-multicellular
-photoautotrophs (use CO2 and light )
-their cell wall is made of cellulose
-alternation of generations (they alternate between two different life stages from gametophytes (haploid) and sporophytes (diploid)

Question 2

main groups of plant kingdom

Answer 2

1. Non-vascular plants (ie. mosses)
2. Vascular plants
   -seedless vascular plants (eg. ferns)
   -seed plants- Gymnosperms (eg. pines)
   -seed plants angiosperms (eg. flowing plants)

Question 2

main groups of plant kingdom

Answer 2

1. Non-vascular plants (ie. mosses)
2. Vascular plants
   -seedless vascular plants (eg. ferns)
   -seed plants- Gymnosperms (eg. pines)
   -seed plants angiosperms (eg. flowing plants)

Question 3

land plants evolved form

Answer 3

they evolved from green alga- the out-group is the nonvascular plants (closes green algae ) then evolved into vascular seedless plants then into vascular seed plants

Question 4

the benefit and challenges of moving into land

Answer 4

benefit:
-spacious
-unfiltered sunlight
-high levels of atmospheric co2 (needed since they are autotrophs)
-a rich source of mineral nutrients
-relatively few herbivores and pathogens
challenges
-less water
-need to resist gravity
-reproduction (since the water used to move the sperm to the egg, however now we don’t have water so how can they reproduce)

Question 5

when is water needed for reproduction in aquatic algae (the ancestor of land plants )

Answer 5

-water was required for fertilization (carrying the sperm to the egg) and dispersal of the zygote

Question 6

dispersal and fertilization trends of archaeplastida

Answer 6

• green algae need water for both dispersal and fertilization
  -bryophytes(non-vascular land plants )use water for fertilization of sperm and use air to disperse spores
• for vascular plants, lycophytes and ferns/horsetails require water for fertilization of sperm and air for the dispersal of spores, however, gymnosperm and angiosperm use air for fertilization of pollen and air to disperse seeds

Question 7

the synapomorphic features between land plants and charophytes

Answer 7

-they have rings of cellulose-synthesizing proteins
-sperm structures are similar (only for land plats with flagellated sperm (that swim meaning require water))
-phragmoplast during cell division (they are microtubules that become new cell wall)

Question 8

what are the evolutionary innovations that allowed plants to adapt to life on land

Answer 8

• sporopollenin
• cuticle, pores
  -Stomata
  -Embryophytes
  -Vascular Tissue
  -roots
  -true leaves

Question 9

sporopollenin

Answer 9

-is a tough polymer
-in Charophytes: it protects zygote from drying
-in Plants: walls of plants spores
-resistant to drying and physical stresses

Question 10

characteristics are synapomorphies of land plants (characteristics unique to land plants )-adapted to water conservation:waxy cuticle

Answer 10

waxy cuticle on epidermis: waterproofing, protection from microbial attack

Question 11

characteristics are synapomorphies of land plants (characteristics unique to land plants )-adapted to water conservation: Stomata

Answer 11

Stomata: pores in the epidermis of leaves (outer layer of the leaf) and other photosynthetic organs
-they allow gas to engage between air and leaf interior
-it’s a site for water to exit via evaporation
-closed stomata: minimize water loss

Question 12

characteristics are synapomorphies of land plants (characteristics unique to land plants )-adapted to water conservation:multicellular dependent embryos

Answer 12

-in contrast to most green algae, zygotes of land plants are retained within the tissued of the female parent (embryo) the parent provides nutrients , the embryo has specialized placental cells (that transfer nutrient)

Question 13

characteristics are synapomorphies of land plants (characteristics unique to land plants )-adapted to water conservation: vascular tissue

Answer 13

-for internal transportation
-it contains lignin ( a complex polymer) which strengthens
the Xylem cells (dead cells) carry water and minerals up from the roots
the Phloem cells that conduct foods made in the leaves during photosynthesis to other parts of plants (living cells)

Question 14

characteristics are synapomorphies of land plants (characteristics unique to land plants )-adapted to water conservation: resources more compartmentalized

Answer 14

-most plants have specialize structure for searching for water and minerals underground Roots ) and light and gasses aboveground (shoots)

Question 15

whats lignin

Answer 15

is a complex organic polymer deposited in the cell walls of plants, making them rigid and woody (allows for resistance against stresses)
the elongation of roots and shoots maximizes exposure to envioenmtal resources (apical meristems are responsible for the growth of the root and shoot )

Question 16

apical mersitem

Answer 16

-are similar to stem cells (undifferentiated tissues ) that can form differentiated cells (they are simple in non-vascular plants, but more complex in vascular plants with the specialization of the roots and shoots)
-the cells produced by the meristems differentiate into various tissue-inducing surface epidermis and internal issues

Question 17

alternation of generation

Answer 17

ALL LANDS PLANTS UNDER GO IT
alternation of haploid (n) multicellular (gametophyte ) and diploid (2n) multicellular body forms (sporophytes) alternate
-gametophytes make gametes through mitosis and sporophytes make spored through meiosis

Question 18

Mycorrhizae

Answer 18

are fungi that help plants colonize land, they were plants’ roots when they first colonized land since they didn’t have one

Question 19

seeds

Answer 19

-are fertilized ovules
-consist of an embryo and nutrients surrounded by a protective coat
-allows the plant to overcome the limitation of having to line in the same place as its parents-since the seed is a portable embryo
-the seed is in the dispersal stage -this contrasts non-seeds with theirs. spores being the travelling stage
-they travel by air, water and animals

Question 20

evolutionary advantage of seeds

Answer 20

they provide evolutionary advantages over spores (they remain dormant for years to days till conditions are favourable for germination)
-seeds have a supply of stored food
-they may be transported by long distances by wind or animals

Question 21

endosperm

Answer 21

is one of the two sperms released by the pollen tube
sperm combined with two nuclei in the central cell of the female gametophyte
-they are triploid (3n), they nourish the developing embryo

Question 22

double fertilization

Answer 22

occurs when the pollen tube discharged two sperm into the female gametophyte within an ovule

Question 23

pollen

Answer 23

male gametophytes in seed plants

Question 24

sporophyte

Answer 24

the diploids phase in the life cycle of plants-which produces spores by meiosis in order to produce gametophytes
-asexual

Question 25

gametophytes

Answer 25

its the haploid phase in the life cycle of plants, they produce gametes using mitosis
-sexual

Question 26

fruits

Answer 26

mature ovary containing seeds
-its the container part of angiosperm
-fruits protect the dormant seeds and aid in dispersal (they attract animals, animals eat them and there you go they are dispersed)

Question 27

flower

Answer 27

-are the reproductive organ in angiosperms
-they turn into fruits once pollination and fertilization occur for the seed to be dispersed
-the pollen tube gets penetrated Polen moved down the tube to the ovule (female gamete )

Question 28

co-evolution (definition and in respect to animals )

Answer 28

definition: mutual evolutionary influence between species.Each of the species involved exerts selective pressure on the other, so they, evolve together (co-evolve)
-co-evolution between plants and pollinators (like animals )
-plants use less energy on pollen production and instead produce showy flowers, nectar and or odours, the pollinators are attracted to things and are rewarded for pollinating the plant with nectar and or
pollen
-plants evolve even more elaborate methods to attract animal pollinators

Question 29

pollination

Answer 29

transfer of pollen to the part of a seed plant containing the ovules

Question 29

pollination

Answer 29

transfer of pollen to the part of a seed plant containing the ovules

Question 30

transpiration

Answer 30

-when plants take up water from the soil and release water vapour into the air from their leaves
-this is important for regulating the plant temp - cooles it down

Question 31

what are plants dominant geenration

Answer 31

sporophyte

Question 32

the advantage of double fertilization in angiosperms compared to reproduction in conifers

Answer 32

double fertilization forms an endosperm that provides nourishment to the embryo.It increases the viability of seeds

Question 33

he difference in life cycles between land plants and charophytes

Answer 33

Answer and Explanation: Charophytes consist of sporopollenin while land plants consist of the cellulose cell wall. Charophytes have flagellated sperms while land plants have round and non-flagellated sperms. Charophytes don’t exhibit alternation of generations like the land plants. instead they are just hapoloids all their life