Comprehensive Plant Biology: Evolution, Structure, and Reproduction

From what ancestral group did all plants evolve?

Aquatic green algae

What is the primary difference between non-vascular and vascular plants?

Non-vascular plants lack specialized tissues for transport, while vascular plants possess xylem and phloem

What is the main function of xylem?

Transporting water and minerals upward from the roots

What is the main function of phloem?

Transporting sugars and nutrients throughout the plant

What distinguishes gymnosperms from angiosperms?

Gymnosperms produce naked seeds in cones, while angiosperms produce seeds enclosed in ovaries

What is the role of stomata in leaves?

Facilitating gas exchange, regulated by guard cells to control water loss

How is water potential defined in plants?

A measure of the potential energy in water, influenced by solute concentration and pressure

What are aquaporins?

Specialized protein channels in cell membranes that facilitate rapid water transport

What is the function of the tonoplast?

The membrane surrounding the vacuole that regulates ion and water movement

What is the difference between cohesion and adhesion in water transport?

Cohesion is the attraction between water molecules; adhesion is the attraction between water molecules and cell walls

How does transpiration contribute to water movement?

It creates negative pressure that pulls water upward through the plant

What are the three main components of a seed?

An embryo, a food supply (endosperm), and a protective seed coat

What is the difference between pollination and fertilization?

Pollination is the transfer of pollen to an ovule; fertilization is the union of pollen and ovule to form a zygote

What are the male and female reproductive organs of a flower?

Stamens (male) and carpels/pistils (female)

What is a fruit biologically?

The mature ovary of a flower that protects and aids in seed dispersal

What initiates seed germination?

Imbibition, or the uptake of water

What is the radicle?

The first root to emerge from a germinating seed

What are meristems?

Regions of active growth in plants that produce new cells

How are plants classified by life cycle?

Annuals (one year), biennials (two years), and perennials (multiple years)

What is the function of the vacuole in plant cells?

Storing water and maintaining turgor pressure for structural integrity

What are the structural components of a leaf?

The blade (where photosynthesis occurs) and the petiole (the stalk)

What is bulk flow in plants?

The pressure-driven movement of fluids through plant tissues

What are the three main functions of roots?

Anchoring the plant, absorbing water and nutrients, and storing food

What are three survival advantages provided by seeds?

Dormancy, nutrient storage, and wide dispersal.

What is the function of the plant cuticle?

A waxy coating that prevents water loss in terrestrial plants.

What are the three primary nutrients supplied by fertilizers?

Nitrogen (N), phosphorus (P), and potassium (K).

What is the role of Rhizobium bacteria in plant nutrition?

They fix atmospheric nitrogen into usable forms (NH4+ and NO3-) within root nodules of leguminous plants.

How do epiphytes obtain nutrients and moisture?

From the air and rain, while growing on other plants without being parasitic.

What distinguishes carnivorous plants from other photosynthetic plants?

They trap and digest insects to supplement their nitrogen intake.

What is a tropism?

A growth response of a plant toward or away from an environmental stimulus.

What are the three stages of plant signal transduction pathways?

Reception, transduction, and response.

What is the primary function of stomata and what triggers their opening?

Gas exchange; triggered by light, CO2 depletion, and circadian rhythms.

What are the three types of fruit based on their development?

Simple (one carpel of one flower), aggregate (many carpels of one flower), and multiple (many carpels of many flowers).

What are the components of a seed?

Embryo, seed coat, endosperm (food), cotyledons, shoots, and roots.

What are the three main tissue systems in vascular plants?

Dermal (protective), vascular (xylem and phloem), and ground (storage/pith/cortex).

What are three mechanisms flowers use to prevent self-fertilization?

Separate male and female flowers, asynchronous maturation of reproductive parts, and pollen rejection.

What are the male reproductive organs of a flower?

Stamens, consisting of a filament and an anther that produces pollen.

What are the female reproductive organs of a flower?

Carpels (pistils), consisting of the ovary, style, and stigma.

What is the difference between angiosperms and gymnosperms regarding seeds?

Angiosperms have seeds enclosed in ovaries (flowers/fruits), while gymnosperms bear naked seeds in cones.

What are basal angiosperms?

The oldest, earliest evolving flowers, such as water lilies and star anise.

What is the evolutionary significance of the relationship between angiosperms and pollinators?

Co-evolution leading to diverse adaptations in both groups for mutual benefit.

What is the result of a pollen grain combining with an ovule?

A zygote, which develops into an embryo and eventually a seed.

What is the function of sepals?

Modified green petals that enclose and protect the flower before it opens.

What is the primary function of petals?

To be brightly colored and attract pollinators.

What are the two components of a leaf?

A blade and a stalk (petiole).

What is the role of meristems?

To generate cells for the growth of new plant organs.