Lecture 6 DA Flashcards
Why are angiosperms so successful (3)?
Because their seeds are protected and they have fast lifecycles. They also have an efficient vascular system.
Do phloem of angiosperms undergo photosynthesis?
Yes.
How do gymnosperms spread pollen, and how do angiosperms improve on this?
Gymnosperms use the wind, while angiosperms developed ways to attract pollinators.
How can angiosperms attract pollinators (4)?
Nectar rewards, pheremones, flower architecture and mimicry. The mimicry will be specific to mimic certain species.
How are seeds of angiosperms dispersed (4)?
By wind, adapted in structure/size.
Water - seed with hydrophobic/philic properties.
Attracting animals - mammals/birds etc
What are some adaptations of angiosperms (4)?
Resistance to drought, salinity, and temperature. Protection from herbivores.
What are the two classifications of angiosperms? Which group has more?
Monocots
Dicots -> more
Regarding the seed, what differentiates dicots from monocots?
Monocots only have 1 seed embryonically, which sprouts as one unit. The seed doesnt split open.
In dicots, the seed splits open, and as the shoot sprouts, will push it up, out the soil.
What are cotyledons, and how are they different in monocots vs dicots?
It is an embryonic leaf.
In monocots, there is only one, which remains under the soil.
In dicots, they have two, and they get pushed up as the shoot sprouts.
Regarding floral parts, how are dicots and monocots different?
Monocot floral parts are usually 3 or in multiples of 3.
Dicots have 4 or 5, or multiples of them.
What are dicot leaves like versus monocot ones (3)?
Monocot leaves have parallel veins, are thinner and will bend more.
Dicots are thicker, and have more structure due to more veins. They are netlike rather than parallel.
What are the pollen grains of monocots like relative to dicot ones?
Monocot pollen have one pore or furrow in them.
Dicots have 3.
What is the vascular distribution like in dicots versus monocots? What does the dicot arrangement allow them to do and produce?
Monocots have vascular bundles distributed evenly in the ground tissue of stems.
Dicot bundles are arranged in a ring around the periphery of the stem.
The dicot arrangement allows them to develop secondary growth there, making bark.
What are the roots of dicots and monocots like? What are their advantages?
Monocots have a more fibrous root system, allowing them to spread out. They are anchored better.
Dicots can grow taller and wider, so use taproots that grow deep.
What do magnolias have that links them to gymnosperms?
Cone shaped stigmas.
Do any dicots have parallel venation?
No, only monocots do.
What are the leaf margins of dicots and monocots like?
Monocots have simple and entire margins.
Dicots have complex and varied margins.
What are stipules and which division are they found in, and what can they have in addition to this? What is the other group’s equivalent structure?
Stipules are found in dicots. Can also have a stalk called a petiole, which is not always found.
Monocots have sheaths instead, and covers around the main stem.
What is the typical leaf arrangement of monocots and dicots?
Monocots have simple leaves, undivided and single.
Dicots can have bipennate and tripennate compound leaves.
What is the structure of the following arrangements: Simple Once compound Bicompound/bipennate Tricompound/tripennate
- Simple - one leaf off the stalk.
- Once compound - branch off the main stem, covered in single leaves (1 branch before reaching the leaves).
- Bipennate - branch off the main stem, which has branches coming off it, covered in leaves (2 branches before reaching the leaves).
- Tripennate - Main stem has branches on it, which have branches coming off them. These smaller branches are also branched, each covered in leaves (3 branches before reaching the leaves).
Are tripennate leaf arrangements common? Which division are they mostly found in?
They are rare, mostly in dicots.
What is the purpose of leaf fragrance (3)?
- Deters predators from eating leaves, which are exposed.
- Plays a role in attracting pollinators.
- Protects against water loss, allowing it to survive against heat and the cold.
What are some stem modifications (4)?
Thorns
Cladodes
Tendrils
Cladophylls
What are some leaf modifications (4)?
Spines
Bracts
Tendrils
What are some petiole modifications (1)?
Phyllodes
What is are advantages of modification to stems, leaves etc (10)?
Reduces water loss Improves photosynthesis Aids water transport Increases nutrient uptake Environmental protection Parasite repellent Sunlight competition Storage Insect traps Pollen attractant
Do monocots and dicots have a mesophyll?
Only monocots.
Which have more stomata, dicots or monocots?
Dicots.
Are monocots more sensitive than dicots?
No, dicots are more sensitive. Monocots can survive harsher environments.
Which of dicots or monocots have a bigger stem?
Dicots.
What does the vascular bundle arrangement of dicots allow the plant to make?
Creates a cambia. As it grows, replaces the epidermic with a corky layer, bark.
Not found in monocots.
Is the pith and cortex of a dicot and monocot clearly distinguished?
Dicots only.
Do both dicots and monocots form annual rings?
Dicots only.
What is the difference in the pericycle between dicots and monocots?
Monocots have a wide pericycle, dicots have a small one.
