chapter 27: flowering plants: reproduction

Question 1

what are the advantages of sexual reproduction

Answer 1

-Sexual reproduction advantageous
-New variation may be better adapted for survival
-Alternation of generations

Question 2

what generation is dominant in flowering plants

Answer 2

Diploid sporophyte (2n) is dominate in flowering plants

Question 3

flowers produce __________ and ___________.

Answer 3

microspores and megaspores

Question 4

what do microspores and megaspores become

Answer 4

gametophytes (n)

Question 5

what are male gametophytes

Answer 5

pollen grains

Question 6

what are female gametophytes

Answer 6

embryo sac

Question 7

how does a flower’s life cycle work

Answer 7

-Sperm travel by pollen tube to embryo sac
-Zygote becomes an embryo
-Ovule develops into a seed
-Ovary becomes fruit

Question 8

how are flowers adapted to land

Answer 8

1. Female gametophyte develops completely within sporophyte
2. Pollen grains not released until they develop a thick wall
3. No external water needed to bring about fertilization
4. Embryo and food stored in protective seed coat

Question 9

functions of flowers

Answer 9

-Sexual reproductive organ
-Composed of whorls of modified leaves
-Serves to attract animal pollinators
-May contain male and female reproductive parts

Question 10

what does monoecious mean

Answer 10

both staminate flowers & carpellate flowers occur on one plant

Question 11

what does dioecious mean

Answer 11

staminate flowers & carpellate flowers occur on different plants

Question 12

where do microspores produce

Answer 12

anthers of flower

Question 13

life cycle of male gametophyte

Answer 13

-Each anther has pollen sacs containing many microspore mother cells
-Microspore mother cells undergo meiosis to produce haploid microspores
-Divide mitotically to form pollen grains
-Contains tube cells & generative cell
-Eventually tube cell becomes pollen tube; generative cell becomes two sperm cells

Question 14

life cycle of female gametophyte

Answer 14

-In an ovule with ovary megaspore mother cell undergoes meiosis to produce four haploid megaspores
-Three of these nonfunctional; one functional
-Nucleus of functional megaspore divides mitotically until there are eight nuclei in the female gametophyte
-When cell walls form now there are seven cells (one is binucleate; polar nuclei )
-The embryo sac (female gametophyte) consists of these seven cells

Question 15

what is double fertilization

Answer 15

-Haploid sperm fertilizes a haploid egg to produce a diploid zygote (2n) which develops into the embryo.
-Other haploid sperm fertilizes the two polar nuclei of the central cell to produce a triploid endosperm (3n)

Question 16

what is an endosperm

Answer 16

-nutritive storage tissue that is derived from union of a sperm nucleus and polar nuclei in the embryo sac
-Begins to develop into a seed!
-Mature seed contains: embryo, stored food, seed coat

Question 17

what is pollination

Answer 17

-In gymnosperms, the transfer of pollen from pollen cone to seed cone; in angiosperms, the transfer of pollen from anther to stigma
-Both by wind
-Angiosperms also by animals

Question 18

what is coevolution

Answer 18

-as one species changes, the other species undergoes adaptation in response, so that the two are suited to one another
-Plants & animal pollinators coevolved

Question 19

what is development

Answer 19

programmed series of stages from a simple to more complex form

Question 20

how does seed development work

Answer 20

-Development of embryo within seed next step
-Cell division, cell elongation, and differentiation of cells into tissue

Question 21

characteristics of monocot cotyledons

Answer 21

-one cotyledon
-Monocot cotyledon stores certain nutrients, absorbs others from endosperm, passes them to embryo

Question 22

characteristics of eudicot cotyledons

Answer 22

-two cotyledons
-Eudicot cotyledons store all nutrients embryo needs

Question 23

what is fruit

Answer 23

-Flowering plant structure consisting of one or more ripened ovaries that usually contain seeds
-Protect & disperse seeds
-Some fruits better at one function over other

Question 24

what are the fruit layers

Answer 24

-Fruit develops, ovary wall thickens, becomes pericarp (many as three layers)
-Exocarp: outermost skin of fruit
-Mesocarp: fleshy tissue between exocarp & endocarp
-Endocarp: boundary around seed(s); may be hard as in peach pits or papery as in apples
-Some fruits are dry fruits because pericarp adheres to seed within
-Fruits of grains often mistaken for seeds

Question 25

what are the methods of the dispersal of fruits

Answer 25

-Air
Wooly hairs, plumes, & wings
-Animals
Ripe, colorful fruits attract animals
Hooks, spines, burs attach fruit to animals
-Ejection
Plants with fruit with slit openings use forced ejection

Question 26

what is germinate

Answer 26

Beginning of growth of a seed, spore, or zygote

Question 27

what do seeds need for germination

Answer 27

1. Oxygen for increased metabolism
2. Adequate warmth
3. Adequate water
   -In temperate region, seeds often require a period of cold weather before dormancy is broken
   -Fleshy fruits contain inhibitors of germination
   -Some seeds require fire or bacterial action before germination can occur

Question 28

what is asexual reproduction

Answer 28

reproduction that produces genetically identical offspring, requires only one parent

Question 29

what is a tissue culture

Answer 29

plant propagation done in laboratory settings

Question 30

what is totipotency

Answer 30

ability of indivdual plant cells to develop into an entire plant

Question 31

why are tissue cultures of plants important

Answer 31

-Use meristem cells grown on agar medium containing auxin, cytokinins, nutrients, water
-Important for propagating fruits & vegetables
-Important for conservation

Question 32

Which of these typically occur in both angiosperms and gymnosperms?
a.
Seeds develop within a cone

b.
Seeds are surrounded by a fruit at maturity

c.
Seeds develop within a flower

d.
Pollen is carried by animal pollinators

e.
Pollen is carried by the wind for pollination

Answer 32

e.
Pollen is carried by the wind for pollination

Question 33

The transfer of pollen from an anther to the stigma of a carpel is
a.
Fertilization

b.
Pollination

c.
Coevolution

d.
Germination

Answer 33

b.
Pollination

Question 34

Which of the following statements is not true about the life cycle of flowering plants?
a.
The female gametophyte is retained within the body of the sporophyte parent generation

b.
The sporophyte may produce microspores or megaspores

c.
The female gametophyte is the seed

d.
The sporophyte is diploid

e.
The male gametophyte is the pollen grain

Answer 34

c.
The female gametophyte is the seed

Question 35

Angiosperms have two separate gametophytes because
a.
These two structures allow fertilization without the need for external water

b.
One can survive and fertilize without the need for external water

c.
This is normal for all sexually reproducing plants, where sperm are produced by microgametophytes and eggs by megagametophytes

d.
This is normal for alternation of generations

Answer 35

c.
This is normal for all sexually reproducing plants, where sperm are produced by microgametophytes and eggs by megagametophytes

Question 36

Double fertilization in an angiosperm produces
a.
A diploid zygote and a diploid endosperm

b.
A diploid zygote and a haploid polar nucleus

c.
A triploid embryo and a diploid endosperm

d.
A diploid zygote and a triploid endosperm

e.
A diploid embryo and a triploid zygote

Answer 36

d.
A diploid zygote and a triploid endosperm