Botany final questions to ponder

Flashcards on Early Land Plants, Evolution, and Systematics

What were the challenges faced by the first plants that moved from water to land?

Desiccation, gravity, reproduction without water, nutrient absorption from soil, gas exchange

How are phylogenetic analyses preferable to older methods of constructing evolutionary relationships?

Older systems grouped organisms by appearance or usefulness, while phylogenetic analyses use shared ancestry and DNA evidence.

What are some examples and pros/cons of artificial classification systems, and why are natural systems preferred?

Classifying by growth habit or use; simpler, practical, but don't reflect evolutionary relationships; natural systems group by common ancestry.

What's the difference between homologous and analogous characteristics, and why are homologous traits better for evolutionary classification?

Homologous traits are from a common ancestor, analogous traits have similar function but different origin. Homologous traits show true evolutionary relationships.

What are some advantages of using molecular data in systematics?

Less subjective, can detect relationships not visible through morphology, resolves convergent evolution issues, high volume of comparable data.

What is the difference between a gametophyte and a sporophyte? Which forms gametes and which forms spores? In which does meiosis take place?

Gametophyte is haploid and produces gametes via mitosis; sporophyte is diploid and produces spores via meiosis; meiosis occurs in the sporophyte.

What features differentiate bryophytes from green algae?

Retain embryos, waxy cuticle, multicellular gametangia, protected spores with sporopollenin, adapted to terrestrial environments

What features distinguish land plants (Embryophytes) from algae?

Alternation of generations, retained embryos, multicellular reproductive organs, specialized tissues for transport (in vascular plants)

What evidence supports the endosymbiotic theory of the origin of the eukaryotic cell?

Double membranes, circular DNA, prokaryote-like ribosomes, reproduce independently by binary fission

What are antheridia and archegonia and how are they adaptive to life on land?

Produce sperm; house and protect eggs; prevent gamete desiccation, offer UV protection, enable reproduction without free-floating gametes

During the evolution of land plants, there is a trend towards:

Increased independence from water

How do mosses and liverworts differ from each other?

Liverworts lack stomata; mosses have them. Liverworts often have flattened, thalloid bodies; mosses are leafy. Moss sporophytes are more complex and upright; liverwort sporophytes are simple. Liverworts can reproduce via gemmae more frequently.

What features distinguish vascular plants from non-vascular plants?

Vascular tissue: xylem and phloem. True roots, stems, and leaves. Dominant sporophyte stage. Greater size and complexity

What are antheridia and archegonia and how are they adaptive?

Prevent desiccation and offer protection

What is a sorus? What group produces sori?

A cluster of sporangia, usually on fern leaves

Why are seedless vascular plants more successful than bryophytes?

Vascular tissue, sporophyte dominance

Why are gymnosperms even more successful than seedless vascular plants?

Pollen, seeds

What are heterospory and homospory?

One spore type, two spore types

Advantage of heterospory

Genetic diversity, protection of gametophyte, seed evolution

Evolution of microphylls vs. megaphylls? How do they differ?

Microphylls: Single vein, evolved from small outgrowths; Megaphylls: Branched venation, evolved from branch systems

Which groups have microphylls and megaphylls?

Lycophytes have microphylls; ferns, seed plants have megaphylls

How does seed plant sperm reach the female gametophyte?

Via pollen tube

What is the advantage of seed plant sperm using a pollen tube?

No need for water for fertilization

Alternation of generations in bryophytes

Gametophyte-dominant

Alternation of generations in seedless vascular plants

Sporophyte-dominant, free-living gametophyte

Alternation of generations in seed plants

Sporophyte-dominant, gametophyte reduced & dependent

Describe the leaves of cycads

Palm-like, pinnate

Describe the leaves of ginkgo

Fan-shaped, deciduous

Describe the leaves of conifers

Needle/scale-like, evergreen

Which gymnosperms have motile sperm?

Cycads, Ginkgo

Why was the seed an important adaptation in plant evolution?

Protects embryo, contains food supply, allows dormancy, aids in dispersal, frees reproduction from water

Which of the following is NOT a characteristic shared by nonvascular and vascular plants?

Dominant gametophytes

Which of the following is a way in which microphylls differ from megaphylls?

Megaphylls evolved from branch systems, microphylls from epidermal outgrowths

Which of the following statements about reproduction in vascular plants is FALSE?

The gametophyte is larger and longer-lived than the sporophyte

Which of the following is NOT an evolutionary trend in vascular plants?

The increased importance of antheridia and archegonia

Which of the following statements about gymnosperms is FALSE?

The male gametophyte produces antheridia

Describe how Agrobacterium tumefaciens “is a natural genetic engineer

It transfers part of its Ti plasmid (T-DNA) into the plant genome

Explain how the Ti plasmid of Agrobacterium tumefaciens is used in the production of transgenic plants

Genes for tumor formation are removed from T-DNA and replaced with a gene of interest

Explain the importance of preserving genetic diversity of crop plants

Genetic diversity allows resistance to disease, pests, and changing climates

Although many drugs can be synthesized, why are plants still important sources?

Plants produce complex compounds hard to replicate synthetically

Why is it important to maintain the genetic diversity of crop plants?

To prevent crop failures, adapt to climate change, and provide materials for future breeding programs

Why use perennial grains instead of annuals?

Perennials have deeper roots, reduce erosion, need less planting, and are more sustainable long-term

Leaves are an example of a type of ____, while roots, seeds and bark are types of ____.

Herb, spice

True or False: Lignin gives structural support to tall plants.

Lignin give structural support to tall plants

True or False: Secondary metabolites deter herbivory.

Secondary metabolites deter herbivory

True or False: Most vascular plants dont have mycorrhizae.

Many vascular plants do have mycorrhizae.