Term
How are female gametophytes
produced? (3) |
|
Definition
• Each ovule contains a cell called a
megasporocyte inside a structure called a
megasporangium.
• The megasporocyte divides by meiosis to produce
four haploid megaspores, of which three
degenerate.
• The surviving megaspore divides by mitosis to
produce the multicellular, haploid gametophyte
known as the embryo sac.
• the embryo sac contains eight haploid nuclei
• most of the nuclei separate
• cell walls form around them to produce seven cells
• large central cell contains two polar nuclei
• one of the other six cells is the egg
– it is located at one end of the gametophyte near an opening to the ovule called the micropyle |
|
|
Term
How are male gametophytes
produced? (6) |
|
Definition
• Inside the anther, structures called
microsporangia contain diploid cells called
microsporocytes.
• Microsporocytes undergo meiosis, producing four
haploid microspores.
• Each of these microspores divides mitotically to
form two cells: a small generative cell enclosed
within a larger tube cell.
• two cells mature to form a pollen grain containing
an immature male gametophyte
• male gametophyte is considered mature when the
haploid generative cell produces two sperm cells
via mitosis
• wall of a pollen grain develops a tough outer coat
that protects the male gametophyte |
|
|
Term
|
Definition
transfer of pollen grains from an
anther to a stigma |
|
|
Term
|
Definition
occurs when a sperm and an egg
unite to form a diploid zygote |
|
|
Term
|
Definition
pollen is carried from the anther of
one individual to the stigma of a different individual |
|
|
Term
|
Definition
pollen falls from the anther of one
individual onto the stigma of the same individual; can
lead to self-fertilization
• some species have mechanisms to prevent selffertilization |
|
|
Term
| pollen can be carried from flower to flower by: |
|
Definition
– abiotic agents:
• wind, water
– biotic agents:
• insects, birds, bats
• most relationships are mutualistic: pollinators
receive food, plants helped with reproduction
|
|
|
Term
mutation continuously introduces
variations in flower size and shape or animal food finding habits causes |
|
Definition
insect and angiosperm
populations frequently change, diverge, and form
new species |
|
|
Term
• after landing on the stigma of a mature flower from
the same species, a pollen grain |
|
Definition
absorbs water
and germinates (resumes growth) |
|
|
Term
male gametophyte produces a long projection
called a ??????? that grows down the length
of the style to the ovary |
|
Definition
|
|
Term
| Double Fertilization Process |
|
Definition
|
|
Term
|
Definition
• ALL angiosperms
• one sperm nucleus (n) unites with the egg nucleus
(n) to form the zygote (2n)
• other sperm nucleus (n) moves through the
female gametophyte and fuses with the polar
nuclei (2n) in the central cell to form a single
triploid (3n) cell |
|
|
Term
|
Definition
embryo, endosperm (food supply),
seed coat |
|
|
Term
|
Definition
single-celled zygote becomes a
multicellular embryo
• zygote divides, produces two daughter cells: the
lower basal cell and the upper terminal cell |
|
|
Term
|
Definition
| divides to form a row of single cells |
|
|
Term
|
Definition
forms a cell mass that ultimately
gives rise to all the cells in the embryo |
|
|
Term
The terminal cell and its progeny sort into three
groups: |
|
Definition
1. exterior layer (protoderm): forms epidermis
2. cells just inside the exterior layer (ground
meristem): form ground tissue
3. group of cells in the core of the embryo (the
procambium): becomes vascular tissue |
|
|
Term
|
Definition
|
|
Term
| How many Cotyledons do monocots have? Dicots? |
|
Definition
|
|
Term
The Role of Drying in Seed
Maturation |
|
Definition
• water loss in seeds: adaptation that prevents
germination on the parent plant
• also ensures that once they have dispersed from
the parent, they will not germinate until water is
available in the environment
|
|
|
Term
|
Definition
thickened ovary walls around seed; form as
fruit matures |
|
|
Term
|
Definition
– protect seeds from damage
– protect seeds from seed predators
– aid in seed dispersal |
|
|
Term
| • most dry fruits (nuts) are dispersed by: |
|
Definition
– wind
– animals
– mechanical action
– OR they simply fall to the ground |
|
|
Term
| fleshy fruits are commonly dispersed by: |
|
Definition
|
|
Term
|
Definition
even though they have been
dispersed, seeds may not germinate for some
time |
|
|
Term
| Seed Dormancy is usually a feature of seeds that inhabit ??????? Environments |
|
Definition
|
|
Term
Seed Dormancy is an adaption
that allows seeds to: |
|
Definition
remain viable
until environmental conditions improve |
|
|
Term
|
Definition
– water
– light
– oxygen
– fire
– scarification: disruption of seed coat |
|
|
Term
|
Definition
some type of reliable signal that conditions
for seedling growth are favorable for a particular
species in a particular environment |
|
|
Term
| Three Phases of Seed Germination |
|
Definition
1. seeds take up enough water to hydrate their existing proteins
and membranes
• oxygen consumption and protein synthesis in the seed increase
2. water uptake stops, the seed begins to manufacture the new
mRNAs and proteins needed to support growth
• mitochondria begin to multiply
3. water uptake resumes as growth begins
• enables cells to enlarge and the embryo to burst from the seed coat |
|
|
Term
Germination Begins with Three
Distinct Phases |
|
Definition
|
|
Term
| • sporophytes produce spores by |
|
Definition
|
|
Term
| gametophytes produce gametes by |
|
Definition
|
|
Term
male and female gametophytes are microscopic &
produced inside |
|
Definition
|
|
Term
In angiosperms, the walls of the ovary
develop into a |
|
Definition
fruit that encloses the
seeds. |
|
|
Term
|
Definition
– stay in one place
– extend their roots and shoots to harvest diffuse
resources
– make their own food through photosynthesis
– can exhibit indeterminate growth: they grow
throughout their lives |
|
|
Term
|
Definition
large amounts of light and
CO2 and a small amount of H2O as an electron
source. |
|
|
Term
| need large amounts of H2O to fill their ?????? and maintain them at normal ????? and ?????? |
|
Definition
|
|
Term
Plants Need Resources to Perform
Photosynthesis |
|
Definition
|
|
Term
root system and the shoot system: two basic plant
systems for acquiring and transporting ?????? |
|
Definition
|
|
Term
|
Definition
below-ground; takes in H2O and
nutrients from the soil |
|
|
Term
|
Definition
above-ground; harvests light and CO2
from the atmosphere |
|
|
Term
| root and shoot systems are connected by ??????, which allows : |
|
Definition
| Vascular Tissue, them to transport between them |
|
|
Term
| What are 3 other nutrients plants need? |
|
Definition
| Nitrogen, Potassium, Phosphate |
|
|
Term
organization of the vascular tissue is identical
in all plants |
|
Definition
|
|
Term
morphology of root and shoot systems and leaves
varies widely |
|
Definition
|
|
Term
Most Root and Shoot Systems Have
the Same General Structures |
|
Definition
|
|
Term
|
Definition
|
|
Term
|
Definition
run more or less horizontally;
numerous |
|
|
Term
| root system functions: (4) |
|
Definition
– anchors the plant in the soil
– absorbs water and ions from the soil
– conducts water and selected ions to the shoot
– stores material produced in the shoot for later use |
|
|
Term
| Consequenses of morphological diversity: |
|
Definition
1. an array of plants can coexist in the same
area with less competition for water and soil
resources
2. most individuals can survive drought years |
|
|
Term
|
Definition
• genetically identical individuals can have very
different root systems if they are growing in
different types of environments
can change in response to
environmental conditions |
|
|
Term
When would roots grow, and
not grow in certain areas? |
|
Definition
– roots actively grow into areas of soil where resources
are abundant
– roots do not grow or die back in areas where resources
are lacking |
|
|
Term
|
Definition
• O2 poor,
waterlogged soil
• shallow root system
• winds + tall tree +
shallow roots +
gravity =
house/car/people
hazard |
|
|
Term
|
Definition
develop from the shoot
system instead of the root system
– corn plants: prop roots that help brace the plant in windy
weather |
|
|
Term
|
Definition
specialized lateral roots called
pneumatophores that function in gas exchange |
|
|
Term
| shoot system: consists of one or more |
|
Definition
|
|
Term
|
Definition
|
|
Term
|
Definition
| where leaves are attached |
|
|
Term
|
Definition
|
|
Term
|
Definition
nodes where leaves attach to the
stem
– may develop into a branch: a lateral extension of the shoot
system |
|
|
Term
|
Definition
at the tip of each stem or branch;
where growth occurs that extends the length of
the stem or branch |
|
|
Term
| shoot system = repeating series of |
|
Definition
nodes,
internodes, leaves, and buds |
|
|
Term
once a part of the shoot system forms, it does not
increase much in size over time
– instead, plants grow by |
|
Definition
|
|
Term
| • morphological variation: (2) |
|
Definition
– allows plants of different species to harvest light at
different locations
• minimizes competition
– allows plants to thrive in a wide array of habitats |
|
|
Term
Because the shoot system continues to grow
through the lifetime of the plant, it can respond to
changes in: |
|
Definition
| environmental conditions. |
|
|
Term
| modified stems are common: |
|
Definition
– stems of cacti: store water
– stolons: stems that run over the soil surface
– rhizomes: stems that grow horizontally
underground
– tubers: rhizomes modified to store
carbohydrates
– thorns: stems that protect the plant |
|
|
Term
|
Definition
| stems that run over the soil surface |
|
|
Term
|
Definition
stems that grow horizontally
underground |
|
|
Term
|
Definition
rhizomes modified to store
carbohydrates |
|
|
Term
|
Definition
| stems that protect the plant |
|
|
Term
|
Definition
expanded portion of leaf; usually wide &
flat |
|
|
Term
|
Definition
|
|
Term
Leaves Vary in Size and Shape
Compound
Simple
Doubly Compound
Needle Like |
|
Definition
|
|
Term
Plants have dramatically different ways to
arrange their leaves in space, to
maximize
: |
|
Definition
| the efficiency of light capture. |
|
|
Term
| other leaf functions include: |
|
Definition
– food or water storage
– climbing
– attracting pollinators
– trapping prey (for carnivorous plants)
– collecting soil |
|
|
