Vascular plants- Angiosperms

Exam 1- set 7

What are the 4 main lineages of angiosperms?

1. Basal grade angiosperms

2. Magnoliids

3. Monocots

4. Dicots (eudicots)

What are basal grade angiosperms?

The earliest-diverging lineages of flowering plants.

What are some characteristics of Basal Grade Angiosperms?

They often have many floral parts, with parts arranged in a less specialized/spiral pattern.

What are magnoliids?

A major lineage of angiosperms that includes plants such as magnolias and laurels.

Common characteristics of magnoliids

Often have many floral parts, frequently arranged in spirals, and many have aromatic oils.

How many cotyledons do monocots have?

1 cotyledon

How many cotyledons do dicots have?

2 cotyledons

What type of leaf venation do monocots have?

Parallel veins

What type of leaf venation do dicots have?

Netlike/branching veins

How are vascular bundles arranged in monocots?

Scattered throughout the stem.

How are vascular bundles arranged in dicots?

Arranged in a ring.

What type of root system do monocots usually have?

Fibrous root system

What are the usual numbers of floral parts in monocots?

Multiples of 3
Example: 3 or 6 petals.

What are the usual numbers of floral parts in dicots?

Multiples of 4 or 5
Example: 4 or 5 petals.

What type of pollen opening do monocots usually have?

One opening

What type of pollen opening do dicots usually have?

Usually three openings

What is the perianth?

The non-reproductive parts of a flower, consisting of the calyx and corolla.

What is the calyx?

The collective term for the sepals.

What do sepals do?

Protect the developing flower bud.

What is the corolla?

The collective term for the petals.

What is the function of petals?

Often attract pollinators.

What is the gynoecium?

The female reproductive structure of a flower.

What is a carpel?

A unit of the gynoecium consisting of a stigma, style, and ovary

What is inside the ovule?

The developing female gametophyte (embryo sac).

What are the three parts of a carpel?

Stigma → Style → Ovary

• Stigma — receives pollen

• Style — connects stigma to ovary

• Ovary — contains the ovules

What is the androecium?

The male reproductive structure of a flower

What is a stamen?

The basic unit of the androecium.

What are the two parts of a stamen?

Anther & Filament

What does the anther do?

Produces and releases pollen.

What does the filament do?

Supports the anther.

What is microsporogenesis?

The formation of microspores through meiosis.

What is microgametogenesis?

The development of the microspore into the male gametophyte (pollen grain).

Remember: ⭐ Micro = male
⭐ Microspore → pollen grain

2n microsporocyte
⬇ MEIOSIS
1n microspores
⬇ MITOSIS/development
1n pollen grain = male gametophyte

What is megasporogenesis?

The formation of megaspores through meiosis.

What is megagametogenesis?

The development of the megaspore into the female gametophyte (embryo sac).

Remember: ⭐ Mega = female
⭐ Megaspore → embryo sac

2n megasporocyte
⬇ MEIOSIS
1n megaspores
⬇ MITOSIS/development
1n embryo sac = female gametophyte

What is pollination?

The transfer of pollen from the anther to the stigma.

What are the two types of pollination?

• Self-pollination: pollen goes to the stigma of the same flower or plant.

• Cross-pollination: pollen moves between different plants of the same species.

What is double fertilization?

A process unique to angiosperms where two sperm cells participate in fertilization.

What does the first sperm fertilize in double fertilization?

The egg → diploid (2n) zygote.

What does the second sperm fertilize in double fertilization?

The two polar nuclei → triploid (3n) endosperm.

What is a major trend in floral evolution?

Flowers have evolved to become increasingly specialized for particular pollinators.

Why did floral specialization evolve?

To improve the efficiency of pollen transfer and attract specific pollinators.

What are some general trends in floral evolution?

• More specialized flower shapes

• Greater specialization for particular pollinators

• Changes in color, scent, nectar, and floral structure

• Increased efficiency of pollen transfer

What floral traits attract beetles?

• Large, open flowers

• Strong or fruity/musty odors

• Often white, cream, or dull-colored

• Lots of pollen

• Accessible flowers

⭐ Beetles often eat pollen and floral tissues.

What floral traits attract flies?

• Often dull-colored

• Strong odors

• Some smell like decaying material

• Open or accessible flowers

⭐ Fly pollination = rotten/decaying smell is a good clue.

What floral traits attract bees?

• Bright yellow, blue, or purple

• Nectar

• Sweet scents

• Landing platforms

• UV patterns that guide bees to nectar

⭐ Bees are especially attracted to yellow/blue/purple + nectar.

What floral traits are associated with butterflies?

• Brightly colored flowers

• Often red, orange, pink, or purple

• Nectar

• Usually flowers with a landing platform

What floral traits are associated with moths?

• Often white or pale-colored

• Strong fragrance

• Nectar

• Frequently open or fragrant at night

⭐ Moths = pale + fragrant + nighttime

What floral traits attract birds?

• Red, orange, or yellow

• Tubular flowers

• Lots of nectar

• Little/no strong fragrance

⭐ Birds = red + tubular + lots of nectar

What floral traits attract bats?

• Large flowers

• Pale/white colors

• Strong or musky odors

• Lots of nectar

• Flowers often open at night

⭐ Bats = large + pale + strong smell + nighttime

What are wind-pollinated flowers like?

• Small and inconspicuous

• Little/no scent

• Little/no nectar

• Produce large amounts of pollen

• Often have exposed anthers

• Stigmas may be feathery to catch pollen

⭐ Wind = lots of pollen, no need to attract animals

What traits are associated with self-dispersal?

Fruits may split open or release seeds near the parent plant.

⭐ Self = stays close to parent

What fruit/seed traits help with wind dispersal?

• Lightweight

• Wings

• Hairs/tufts

• Parachute-like structures

• Dry fruits that release seeds

⭐ Wind = light + winged/hairy

What fruit/seed traits help with water dispersal?

• Buoyant/floating

• Waterproof or water-resistant coverings

• Able to survive being transported by water

⭐ Water = floats

What fruit traits attract animals for dispersal?

• Fleshy

• Sweet

• Colorful

• Often aromatic

• Contains seeds that can survive passage through an animal's digestive system

How do animals disperse fruits/seeds?

They may eat fruits and transport the seeds, or seeds may attach to their bodies.