Transcript 1. Outline the angiosperm life cycle.

Chapter 38 Reading Quiz
1.
2.
3.
4.
5.
By what process do sporophytes make
spores?
What are the two sterile parts of a
flower?
What is the name of the food-storing
tissue of a seed?
Name one condition that could break
“seed dormancy”.
In plants, what is asexual reproduction
also known as?
1. Outline the angiosperm life cycle.
• Has alternation of generations
• Sporophyte is everything from zygote to
mature plant
• Gametophyte is just pollen (sperm) &
embryo sac (egg) 
2. List the four floral parts in their order
from outside to inside of the flower.
• Sepals  green petallike structures
• Petals  colored
structures
• Stamens  male
structures
• Carpels  female
structures 
3. Distinguish between complete and
incomplete flowers.
• Complete flowers  those that have all
four plant organs
• Incomplete flowers  those lacking one or
more of the four organs
ex: grasses are incomplete (lack petals) 
4. Distinguish between a perfect and
imperfect flower.
• Perfect flower  those equipped with both
stamens and carpels (can still lack sepals or
petals)
• Imperfect flower  have only stamens or
carpels (are always incomplete) 
5. Distinguish between monoecious and
dioecious.
• Monoecious  if staminate & carpellate
flowers are located on the same individual
plant
ex: corn
• Dioecious  when staminate & carpellate
flowers are on separate plants
ex: date palms 
6. Explain by which generation, structure,
and process spores are produced.
• Generation  sporophyte
• Structure  within flower structure
• Process  meiosis 
7. Explain by which generation, structure and
process gametes are produced.
• Generation  gametophyte
• Structure  within pollen & embryo sac
structures
• Process  mitosis 
8. Describe the development of a pollen grain
in angiosperms.
• Within the pollen sacs of the anther, the
diploid cells undergo meiosis
• This forms 4 haploid microspores
• Each one divides once by mitosis and
produces 2 cells (generative & tube)
• These 2 cells together constitute a pollen
grain (an immature male gametophyte) 
9. Of the pollen grain, distinguish among
generative cell, tube cell, and sperm nucleus.
• Generative cell  the half of the pollen
grain that will form 2 sperm
• Tube cell  when the pollen lands on the
stigma of the carpel, the pollen tube begins
to grow through to deliver the sperm to
the egg
• Sperm nucleus  the 2 sperm created by
the generative cell 
10. Describe the development of the embryo
sac, and explain what happens to each of its
cells.
• Embryo sac:
1. Antipodal cells (3)
2. Polar nuclei (2)
3. Egg (1)  female gamete
4. Synergids (2)  flank egg cell 
11. Describe how pollen can be transferred
between flowers.
• Pollen can be transferred by:
1. Wind
2. Insects
3. Birds 
12. Describe mechanisms that prevent selfpollination, and explain how this contributes
to genetic variation.
•
1.
Similar to immune response in animals
“S-genes” recognize self
- if pollen & stigma have same alleles at
S-locus, then pollen will not grow tube
 The incompatibility can happen at
different locations
- block inside pollen itself
- response by carpel’s stigma 
13. Outline double fertilization and describe
function of endosperm.
• the pollen tube grows down the style toward the
ovary
• The generative cell divides by mitosis and forms
two sperm
• A chemical attractant draws the sperm to the
ovary & discharges the two sperm
• One sperm fertilizes the egg to form the zygote
• The other combines with the 2 polar nuclei to
form a triploid nucleus
• This gives rise to the endosperm, which stores
food 
14. Describe the development of a plant
embryo from the first mitotic division to an
embryonic plant with rudimentary organs.
• Endosperm development  rich in nutrients
• Embryo development  first division is
transverse, splitting into basal & terminal cells
• Terminal gives rise to most of the embryo
• Basal becomes thread of cells to anchor the
embryo & transfer nutrients
• Rudimentary cotyledons appear, and the embryo
elongates, stem & root meristems begin to grow
out 
15. Draw a seed diagram and label and explain
the following structures: a. seed coat
b. embryo c. endosperm d. cotyledons
16. Explain how a monocot and dicot seed
differs.
• Monocot  one cotyledon (seed leaf) for
embryo nutrition
• Dicot  two cotyledons for embryo
nutrition 
17. Describe several functions of fruit and
explain how fruits form.
Functions 
• Enclose & protect seeds
• Aid in dispersal by wind or animals
Formation 
• Begins to develop after pollination triggers
hormonal changes that cause the ovary to
grow
• Pericarp is the thickened wall of the ovary
(fruit) 
18. Distinguish among simple, aggregate, and
multiple fruits and give examples of each.
Simple  a fruit derived from a single ovary
• May be fleshy (cherry) or dry (soybean)
Aggregate  results from a single flower
that has several carpels
• Blackberry, raspberry
Multiple  develops from an inflorescence
(a group of flowers tightly clustered
together)
• Pineapple 
19. Explain how seed dormancy can be
advantageous to a plant and describe some
conditions for breaking dormancy.
• Seed dormancy  very low metabolic rate & no
growth or development
• Increases chance that seed will germinate at a
time that is advantageous
Conditions  environmental
• Substantial rainfall
• Intense fire
• Extended exposure to cold
• Passage through an animal’s digestive tract 
20. Explain how a seed mobilizes its food
reserves and describe the function of
aleurone,  -amylase, and gibberellic acid.
• Once seed imbibes water, this triggers the seed
to break it’s coat and begin digesting the food
supply
• This happens because hormones called gibberellins
(GA) signals the aleurone (thin outer layer of
endosperm
• The aleurone synthesizes & secretes the digestive
enzymes that hydrolyze the food
• The  - amylase is the enzyme that hydrolyzes the
food supply to make it available to the now
developing seed 
21. Describe variations in the process of
germination including the fate of the radicle,
shoot tip, hypocotyl, epicotyl, and cotyledons.
• Radicle  the root of the embryo, emerges
from the seed first
• Shoot tip  breaks the soil surface
• Hypocotyl  straightening of this pulls the
shoot & cotyledons from the soil
• Epicotyl  elongation and “unhooking” of
this pulls new shoot & leaves to the surface
• Cotyledons  some rise with the shoot
(bean), some stay underground (pea) 
22. Distinguish between sexual reproduction
and vegetative reproduction.
• Sexual  involves two different individual
plants (one male, one female)
- result in genetic variation
• Vegetative  essentially a clone of a plant,
reproduced through asexual means
- possible due to indeterminate growth 
23. Describe natural mechanisms of
vegetative reproduction in plants including
fragmentation and apomixes.
• Fragmentation  the separation of a
parent plant into parts that re-form whole
plants (one of the most common types)
• Apomixes  in dandelions and others
- produce seeds without their flowers
being fertilized
- a diploid cell in the ovule gives rise to the
embryo, and the ovules mature into seeds,
which are dispersed 
24. Describe various methods horticulturists
use to vegetatively propagate plants from
cuttings.
• Methods are based on the ability of plants to form
adventitious roots or shoots
• Most houseplants & orchard trees are produced by
cuttings
• At the cut end of a stem or shoot, a mass of
dividing, undifferentiated cells called a callus
forms, and the roots develop from this
• Grafting  a cutting can be grafted onto another
of a closely related species 
25. Explain how the technique of plant tissue
culture can be used to clone and genetically
engineer plants.
• It is possible to grow whole plants by
culturing even single parenchyma cells in an
artificial medium with nutrients &
hormones
• Can introduce foreign genes by firing DNA
coated pellets into the cells 
26. Describe the process of protoplast fusion
and its potential agricultural impact.
• Protoplast fusion 
- being coupled with tissue culture methods
- protoplasts are plant cells that have had
their cell walls removed
- can be screened for mutations & improve
the agricultural value of the plant
- could fuse two protoplasts that otherwise
would be incompatible & produce a hybrid

Protoplasts
27. Define monoculture and list its benefits
and risks.
• Monoculture  the cultivation of large
areas of land with a single plant variety
• Has helped farmers feed populations
• Fragile ecosystems; where there is little
genetic variability, there is little
adaptability 
28. Define growth, morphogenesis, and
cellular differentiation.
• Development  the sum of all of the changes that
progressively elaborate an organism’s body
• Growth  an irreversible increase in size, results
from cell division and cell enlargement
• Morphogenesis  accompanies growth; it is the
development of form
• Cellular differentiation  the acquisition of a
cell’s specific structural and functional features 
29. Describe how the plane of cell division is
determined.
• The plane in which a cell will divide is
determined during the late interphase
• The microtubules of the cytoskeleton
rearrange
• The band that they form will be where the
cell will divide 
30. How is cellular differentiation
controlled?
• Cellular differentiation is controlled by the
genes
• Differentiation continues throughout the
plant’s life
• Meristems sustain this indeterminate
growth
• Differentiation reflects the synthesis of
different proteins in different types of
cells 
31. Describe what pattern formation and
positional information is.
• Pattern formation  the development of
specific structures in specific locations
- a key element in the overall development
of an organism’s form
• Positional formation  what pattern
formation depends upon
- signals of some kind that indicate each
cell’s location within an embryonic
structure, such as a root tip 
32. Describe pattern formation in flower
development.
• The transition of a vegetative shoot tip into a
floral meristem
• Begins with a combination of environmental clues
(daylength, hormones)
• The “meristem identity genes” are switched on
• The protein products of these genes are
transcription factors that help to activate the
genes required for development of the floral
meristem
• Once induced to flower, positional info commits
each part to become one plant organ 