Plantae

Question 1

Alternation of generations (sporic life cycle)

Answer 1

both multicellular haploid and diploid generations, such that this life cycle is characterized by an alternation-of(multicellular haploid and diploid)-generations. This life cycle is an innovation of land plants.

Question 2

Angiosperms

Answer 2

“enclosed seed”

Question 3

Antheridia

Answer 3

produce male gametes (sperm cells).

Question 4

Apical meristems

Answer 4

Embryonic plant tissue in the tips of roots and in the buds of shoots that supplies cells for the plant to grow in length.

Question 5

Archegonia

Answer 5

produce female gametes (egg cells). (adaptive value: retention of egg in archegonium provides protection for the zygote).

Question 6

Bifacial vascular cambium

Answer 6

The bifacial vascular cambium of seed plants produces secondary xylem to the inside of the plant, and secondary phloem to the outside of the plant.

Question 7

Carpel

Answer 7

the female sex organ of flowering plants.

Question 8

Chloroplast DNA inversion

Answer 8

The chloroplast DNA inversion happened in the ancestor of monilophytes and seed plants. It is when the DNA sequence in chloroplasts are reversed/inverted.

Question 9

Companion cell

Answer 9

which nurture the sieve tube cells.

Question 10

Determinate growth

Answer 10

once a plant reaches a predetermined size, it will stop growing.

Question 11

Diploid

Answer 11

(2n) (of a cell or nucleus) containing two complete sets of chromosomes, one from each parent.

Question 12

Double fertilization

Answer 12

where each of the two sperm in a pollen grain fertilizes an egg.

Question 13

Embryo

Answer 13

multicellular and diploid; product of the mitotic division of the zygote

Question 14

Flower

Answer 14

sexual structure of flowering plants

Question 15

Fruit

Answer 15

an expanded/ripened ovary.

Question 16

Gametangia

Answer 16

the multicellular organs of the gameteophyte that produce gametes by mitosis (adaptive value: more gamete producing cells enable generation of more gametes per generation).

Question 17

Gametes

Answer 17

sexual haploid cells, typically eggs and sperm.

Question 18

Gametophyte

Answer 18

haploid ‘gamete plant’ that produces gametes by mitosis in gametangia.

Question 19

Haploid

Answer 19

(n); (of a cell or nucleus) having a single set of unpaired chromosomes.

Question 20

Heterospory

Answer 20

(a sporic life cycle with two kinds of spores) evolved independently three times in vascular plants: a. in lycophytes, b. in leptosporangiate ferns, and c. in seed plants
Homospory - male and female gametangia may occur on each individual.

Question 21

Hornwort

Answer 21

green sporophyte with indeterminate growth.

Question 22

Indeterminate growth

Answer 22

growing for its entire life time.

Question 23

Lateral meristems

Answer 23

Cylinder of unspecialized meristem cells that divide laterally to give rise to cells that further divide and differentiate and specialize to form the secondary vascular tissue (secondary xylem and secondary phloem) Xylem tissue is produced on the inner side of the cambium ring and phloem tissue is produced on the outer side of the ring. There are two types of cambium layers: one that produces more vascular tissue, and the other that produces cork.

Question 24

Megagametophyte

Answer 24

haploid female gametophyte.

Question 25

Megaphyll

Answer 25

(mega = big, phyll = leaf) are leaves with a many branched vascular strands that evolved from modified side branches in euphyllophytes. (“true” leaves with more complex vascularization derived from side branches).

Question 26

Megaspore

Answer 26

(note that only one of the four megaspores survive; three of the megaspores experience apoptosis). The megaspore in turn undergoes three mitotic divisions to give rise to the female megagametophyte, the embryo sac.

Question 27

Meiosis

Answer 27

cell division that results in a reduction of ploidy

Question 28

Meristem

Answer 28

meristematic cells are cells that have the ability to divide.

Question 29

Microgametophyte

Answer 29

male heterosporous plant produce male gametes (sperm cells).

Question 30

Microphyll

Answer 30

(micro = small, phyll = leaf) are leaves with a single vascular strand that evolved from sterile lateral sporangia in lycophytes. (simple leaves with a singular vascular strand derived from sterile lateral sporangia)

Question 31

Microspore

Answer 31

Within the anthers are microsporocytes; these are the single diploid cells that undergo meiosis to give rise to microspores, which in turn undergo mitosis to give rise to the haploid male (micro)gametophyte, the pollen grain.

Question 32

Mitosis

Answer 32

cell division that results in no reduction of ploidy

Question 33

Ovary

Answer 33

the base of the carpel that surrounds the seed

Question 34

Petal

Answer 34

modified leaves that surround the reproductive parts of flowers. Help attract pollinators.

Question 35

Phloem

Answer 35

conducts products of photosynthesis (carbohydrates) from source to sink regions of the plant by the Pressure Flow Model. The tissue is comprised of sieve-tube elements (which are alive at maturity but lack many cell components) and companion cells (which nurture the sieve tube cells). [evolved one time in MRCA of tracheophytes]

Question 36

Plasmodesmata

Answer 36

Gap junctions (connectivity between cells in multicellular plants” that only allow transport of certain molecules between cells; determined by size.

Question 37

Poikilohydry

Answer 37

The bryophyte’s ability to be desiccated to 0% water and still survive.

Question 38

Pollen

Answer 38

The highly reduced male gametophyte of seed plants is the pollen grain; the typical pollen grain of seed plants:

1. Is comprised of just 4–8 cells
2. Lack multicellular male gametangia (i.e., no antheridia)
3. Includes 2 male gametes (sperm cells)
4. Is enclosed in sporopollenin, a resilient coat that protects the pollen from desiccation and may be elaborated to enhance dispersal.

Adaptive significance of pollen The origin of the pollen is another major innovation in seed plants that confers two major benefits:

1. Facilitates efficient dispersal of sperm over great distances to pollenate female gametophytes (they are flying microgametophytes!)
2. Delivery of sperm to megagametophytes without water!

Question 39

Primary growth

Answer 39

the ability to increase the length of the plant by means of apical (shoot and root) meristems, and the ability to increase the girth of the growing plant by means of vascular cambium.

Question 40

Root

Answer 40

have evolved independently twice in vascular plants:

a. simple “roots” comprised of a dichotomously branching rhizome (underground stem) with “rootlets” derived from microphyllous leaves evolved in lycophytes
b. complex roots with complex branching and root hairs derived from the dermis evolved in euphyllophytes

Question 41

Secondary growth

Answer 41

Adaptive significance of secondary growth: The origin of the vascular cambium is a major innovation that confers four major benefits:

1. Allows taller growth of the sporophyte, which facilitates competition for sunlight (enhanced photosynthesis) and more efficient dispersal of pollen and seeds
2. Constant rejuvenation of the xylem (that gets clogged with resins over time)
3. Constant rejuvenation of the phloem (which both maintains nutrient transport throughout the plant and maintains the integrity of the bark that protects against disease)
4. Formation of bark prevents water loss and infection Note that secondary growth evolved independently within Lycophytes (in quillworts), but this involved a unifacial vascular cambium that produce secondary xylem but not secondary phloem

Question 42

Seed Sepal

Answer 42

an outer whorl of sepals (collectively calyx)

Question 43

Sieve tube

Answer 43

which are alive at maturity but lack many cell components

Question 44

Sori

Answer 44

clusters of sporangia

Question 45

Sporangium

Answer 45

the multicellular organs of the sporophyte that produce spores by meiosis (adaptive value: more spore producing cells enable generation of more spores per generation

Question 46

Spore

Answer 46

are the single haploid cells that give rise to the gametophyte generation, coated in sporopollenin (adaptive value: protects spores from desiccation and facilitates transport by wind)

Question 47

Sporophyte

Answer 47

diploid ‘spore plant’ that produces spores by meiosis in sporangia.

Question 48

Stamen

Answer 48

the outer whorl is the male sex organs, the stamens, which include a basal shaft (the filament) and apical microsporangia (anthers).

Question 49

Stomata

Answer 49

small pores mainly found in the leaves of plants that allow gas and light into and out of the plant.

Question 50

Thallus

Answer 50

meaning “a green shoot” or “twig,” is the undifferentiated vegetative tissue of some organisms in diverse groups such as algae, fungi, some liverworts, lichens.

Question 51

Tracheid

Answer 51

cells with lignified cell walls that provide structural support and comprise the xylem.[evolved one time in MRCA of tracheophytes]

Question 52

Vessel element

Answer 52

increase the efficiency of water and mineral transport. [evolved twice]

Question 53

Waxy cuticle

Answer 53

waxy coating to prevent desiccation

Question 54

Xylem

Answer 54

conducts water and minerals from the roots to the aerial parts of the plant by a passive Transpiration-Cohesion-Tension system. The tissue is comprised of tracheid cells that are dead at functional maturity and have cell walls that are fortified with lignin.

Question 55

Zygote

Answer 55

fusion of haploid gametes (egg+sperm) to form a single celled diploid zygote. unicellular and diploid