General Biology: Chapter 30

Plant Diversity

Order of adaptations critical for plant success on land

waxy cuticle, vascular tissue, seeds, flowers

First group of plants to adapt vascular tissue

pteridophytes

What did the evolution of vascular tissue allow plants to do?

become bigger and colonize terrestrial environments

5 things that set SED plants apart from all other plants

seeds, ovules, pollen, heterospory, reduced gametophytes

What makes a seed?

embryo, food supply, seed coat

What is the trend between sporophyte and gametophyte?

sporophyte dominant life-cycle

What are the advantages of needle-like structures?

they are evolved leaves that lived in different conditions, colder environments = needing more water (reduces surface area, less water loss)

Gymnosperms

“naked seed” plants, including conifers, typically on cones or spruces

Angiosperms

flowering plants, 90% of living plant species

Advantages of pollen

no need for water to bring sperm to egg, no flagella

What was the big event that allowed gymnosperms

permian mass extinction

What is the main distinctive feature from gymnosperm to angiosperm?

seed is now enclosed in either a flower or a fruit

If grasses are angiosperms, why do they not have colorful flowers?

they rely on wind dispersal

Advantages of Gymnosperms

reproductive independence from water, seed protection and nourishment, adaptation to harsh climates, ecological and economic importance

Advantages of Angiosperms

vast source of food (grain, fruit, vegetables) and medicine (pharmaceuticals, traditional remedies), ecosystems, biodiversity, provide habitats

Sporophyte

Male vs Female Gametophyte

Monocots

have 1 cotyledon (seed leaf), parallel leaf veins, scattered vascular bundles, and flower parts in multiples of 3

Dicots

have 2 cotyledons, net-like leaf veins, vascular bundles in a ring, and flower parts in multiples of 4-5

Advantages of indigestible seeds (ecological)

seed dispersal, reduced competition, enhanced germination, nutrient-rich deposition, colonization of new habitats

Advantages of indigestible seeds (humans)

improved digestion and gut health, prebiotic effects, chronic disease management, cholesterol and blood sugar control, weight management

Wind Pollinated Plants

use of wind to transport pollen form one flower to another for reproduction

Insect Pollinated Plants

attract insects with bright colors, strong scents, and nectar

Wind Pollinated Plant examples

grasses (wheat, rice, corn, barely, oats, maize), trees (pines, spruces, oaks, birches, willows,) ragweed

Insect Pollinated Plant examples

fruits (apple, pear, cherries) vegetables (tomatoes, squash, cucumbers) flowers (sunflowers, roses, clover)

How and why will plants look different depending on their pollination method?

they have evolved specific physical adaptations (smell, color, size) to maximize efficiency of pollen transfer by their own pollinating agents, wind pollinated angiosperms don’t need flashy features

How will human population change the animal and plant diversity?

humans destroy habitats through deforestation and urban sprawl, increasing pollution and climate change