Section 27.3 (Exam 2) Flashcards
Flowers and Fruits Led to Increased Diversification of Angiosperms
Angiosperms (“enclosed seeds”) have ________________.
flowers and fruits
After fertilization, the ovary of an angiosperm develops into a ___________.
true fruit
Ovules and seeds are enclosed in a modified _______ called a _________.
leaf;carpel
What is the function of the carpel?
Provide protection for the ovules and seeds and prevent self-pollination
In angiosperms, the female gametophyte is highly reduced, usually only ________.
7 cells
The xylem of most angiosperms has specialized _____________________________.
water-transporting vessel elements
Xylem in angiosperms has _____________ that provide support.
fiber cells
Woody angiosperms have _____________ growth that increases their stem diameter.
secondary
In angiosperms, phloem has unique cells called ____________ cells.
companion
Name some synapomorphies of angiosperms that can differentiate them from gymnosperms.
Germination of pollen on a stigma
Double fertilization
Triploid endosperm that is nutritive tissue for the embryo
Phloem with companion cells
Flowers are the sexual structures of _____________.
angiosperms
A group of flowers form a ______________.
florescence
All parts of a flower are modified _______.
leaves
Stamens, consisting of filament and anther, bear the ________________.
microsporangia
Carpels, (also called pistil) bear ____________.
megasporangia
________ consist of the stigma, style, and ovary.
Carpels
What are the 4 organs of a flower?
Sepals, petals, stamens and carpels
What are all the petals of a flower collectively called? All the sepals?
Corolla; calyx
What is the role of petals and sepals?
Attracting animals pollinators
What is a common role of the calyx (all the sepals collectively)?
protecting the immature flower in the bud
Early diverging flowers also have _______.
tepals
What are the two types of flowers?
Perfect and imperfect
What differentiates perfect flowers?
They have both the male and female sporangia on the same flower, (not on the same plant and separate flowers)
What differentiates imperfect flowers?
They don’t have megasporangia and microsporangia on the same flower.
What are monoecious flowers?
male and female flowers grow on the same plant, (not the same flower)
What are the two types of imperfect flowers?
Monoecious and dioecious flowers
What are dioecious flowers?
male and female flowers grow on different plants
Evolution has also favored flowers with _____ styles and filaments.
long
Natural selection has favored longer styles and filaments in flowers because it increases the likelihood of ___________.
pollination
Most angiosperms are pollinated by ________.
animals
Why do a longer style and filaments increase likelihood of pollination in flowers?
Making them more accessible to insects and easier to catch the wind (pollen)
Many flowers entice pollinators with nectar and pollen as ______________.
food rewards
Plants and their pollinators ____________.
coevolved
Flowers can specialize based on their pollinators. What specializations do bee-pollinated flowers have?
They are often red and odorless. They often have conspicuous markings or nectar guides that are only visible to bees.
Insect-pollinated flowers have a characteristic _____.
odor
Which type of plants undergo double fertilization?
angiosperms
What is characteristic of the pollen grains that are involved in double fertilization?
They have two sperms
In double fertilization, one sperm combines with the ______ to produce a diploid zygote. The other sperm combines with ___________ to form the _____________________.
egg; 2 haploid nuclei; triploid endosperm
In angiosperms, the endosperm provides food for the ____________.
early embryo
The embryo of angiosperms consists of two parts:
Embryonic axis that forms the stem and root, and cotyledons which become the first leaves.
The ovule is protected within the ________.
carpel
What are the steps to seed formation in angiosperms, starting with pollination?
Pollination –> Pollen tube formation –> Fertilization
Megasporangium (2n) house the _____________.
megasporocyte (2n)
The megasporocyte (2n) produces 4 _____________ via meiosis. One of these develops into the female gametophyte, the egg, and the other 3 degenerate.
megaspores (1n)
Microsporangium (2n) house _____________.
microsporocytes (2n)
Microsporocytes (2n) produce 4 ______________ via meiosis. Most of these develop into the male gametophyte, the sperm.
microspores (1n)
Name 4 ways fruits can aid in seed dispersal.
Attaching to animal (burrs)
Being eaten by animals (berries)
Floating on water (coconuts)
Traveling on wind (maple seeds)
A fruit could consist of only the mature ______________, but it may also consist of the other parts of the flower or associated structures.
ovary and seeds
What are simple fruits?
they develop from one carpel
What are aggregate fruits?
the develop from several carpels of a single flower
What are multiple fruits?
they form from a cluster of flowers
What are accessory fruits?
they develop from parts in addition to carpels and seeds
What are the 4 types of fruit that are classified because of what they develop from?
simple, aggregate, multiple, and accessory
Name two example of simple fruits.
plums and cherries
Name an example of an aggregate fruit.
raspberries
Name two examples of multiple fruits.
pineapples and figs
Name three examples of accessory fruits.
apples, pears, and strawberries
What are the two major clades of angiosperms?
monocots and eudicots
The two major clades of angiosperms, monocots and eudicots, are divided based on how many cotyledons they have. What are cotyledons, and what is their function?
They absorb nutrition from the endosperm, and they are the first leaves that can perform photosynthesis after germination.
How many cotyledons do monocots have?
one
How many cotyledons do eudicots have?
two
What are the 4 main differences between monocots and eudicots?
Number of cotyledons
Leaf vein patterns
Number of petals on flowers
Arrangement of vascular bundles
What is the leaf vein pattern of monocots? Of eudicots?
Monocots have parallel leaf veins. Eudicots have branching leaf veins.
How can you tell whether an angiosperm is a monocot or eudicot by looking at its flower petals?
If it’s a monocot, the number of petals will be divisible by 3. If it’s a eudicot, the number of petals will be divisible by 4 or 5.
How can you tell whether an angiosperm is a monocot or eudicot by looking at the arrangement of its vascular bundles?
Monocots have scattered vascular bundles. Eudicots have circular vascular bundles.
