Kingdom Plantae – Mosses, Ferns, and Seed Plants

These flashcards cover major topics from the lecture on Kingdom Plantae, including general plant characteristics, non-vascular plants (mosses, liverworts, hornworts), seedless vascular plants (ferns and allies), and seed plants (gymnosperms and angiosperms). Key life-cycle concepts, structural adaptations, ecological roles, and representative examples are included to aid comprehensive exam review.

What nutritional strategy do all members of Kingdom Plantae use?

They are autotrophic, synthesizing their own food by photosynthesis.

Which polysaccharide makes up plant cell walls?

Cellulose composed of β-glucose chains.

Which organelle carries out photosynthesis in plants?

The chloroplast.

What group is considered the closest ancestor of land plants?

Green algae.

Name four features shared by green algae and plants.

Chlorophyll pigments, cellulose cell walls, starch food reserve, and cytokinesis by a cell plate.

What waxy adaptation helps plants prevent desiccation?

The waxy cuticle on leaf surfaces.

Which leaf pores allow atmospheric CO₂ uptake?

Stomata.

What are multicellular sex organs of plants called collectively?

Gametangia.

Define alternation of generations in plants.

A life cycle alternating between a multicellular haploid gametophyte and a multicellular diploid sporophyte.

Which generation (haploid or diploid) generally dominates the life cycle of most plants?

The diploid sporophyte generation.

What male gametangium produces sperm in plants?

Antheridium.

What female gametangium produces eggs in plants?

Archegonium.

During fertilization, what forms immediately after a sperm unites with an egg?

A diploid zygote.

Which cell division produces haploid spores in the plant life cycle?

Meiosis in sporogenous (spore-mother) cells.

List the three major groups in the plant kingdom classification shown.

Non-vascular (Bryophytes), Seedless vascular (Ferns and allies), Seed vascular (Gymnosperms and Angiosperms).

Give three non-vascular plant phyla.

Bryophyta (mosses), Hepaticophyta (liverworts), Anthocerotophyta (hornworts).

In mosses, which generation is nutritionally independent?

The gametophyte; the sporophyte remains attached and dependent.

What root-like structures anchor moss gametophytes?

Rhizoids.

List the four main parts of a moss sporophyte.

Foot, seta, capsule, and caliptra.

Where does meiosis occur in a moss?

Inside the capsule of the sporophyte.

State two ecological roles of moss colonies.

They stabilize soil to reduce erosion and create micro-habitats for small animals.

Name two economically important moss genera.

Sphagnum and Polytrichum.

What growth form characterizes liverwort gametophytes?

A flattened, lobed thallus made of one cell layer.

Which stalked structures bear liverwort sex organs?

Antheridiophores (male) and archegoniophores (female).

What asexual reproductive bodies do liverworts produce?

Gemmae in gemma cups.

Give an example species of liverwort.

Marchantia polymorpha.

Why are hornwort sporophytes described as "horn-like"?

Because they are elongated, splitting capsules that resemble small grass blades or horns.

Which phylum contains hornworts?

Anthocerotophyta.

What distinguishes vascular from non-vascular plants?

Presence of lignified xylem and phloem tissues for transport and support.

Name the two vascular tissues and their functions.

Xylem transports water; phloem transports sugars and organic products.

Why can vascular plants attain greater height than bryophytes?

Lignified vascular tissues provide structural support.

What are microphylls?

Small leaves with a single unbranched vein.

Define megaphylls.

Large leaves with a branched network of veins.

What is a sporophyll?

A modified leaf that bears sporangia.

What term describes clusters of sporangia on fern leaves?

Sori (singular: sorus).

Differentiate between homosporous and heterosporous plants.

Homosporous plants make one spore type that grows into a bisexual gametophyte; heterosporous plants make microspores (male) and megaspores (female).

Are most true ferns homosporous or heterosporous?

Homosporous.

What is the typical leaf of a fern sporophyte called?

A frond, often divided into leaflets (pinnae).

Where do fern gametophytes (prothalli) develop?

From wind-dispersed spores, usually on moist soil surfaces.

In fern reproduction, what environmental condition is required for fertilization?

Water, allowing flagellated sperm to swim to eggs.

Which early vascular plant lacks true roots and leaves yet has vascularized stems?

Whiskferns (Phylum Psilotophyta).

Describe dichotomous branching.

A stem splits into two equal branches, characteristic of whiskferns.

What is the main photosynthetic organ of whiskferns?

The green aerial stem.

Name the genus that represents whiskferns today.

Psilotum (e.g., Psilotum nudum).

Which phylum includes horsetails?

Sphenophyta (genus Equisetum).

What substance impregnates horsetail stems, giving them a gritty texture?

Silica.

What reproductive structure sits at the tip of a horsetail stem?

A strobilus (cone) bearing sporangia.

In horsetails, are sporophytes or gametophytes larger and longer-lived?

Sporophytes; gametophytes are small thalli.

Which phylum contains club mosses and spike mosses?

Lycophyta.

Give one homosporous club moss genus.

Lycopodium.

Which spike moss genus exhibits heterospory?

Selaginella.

Why is heterospory evolutionarily important?

It is a precursor to seed evolution by separating male and female gametophyte development.

List three key differences between spores and seeds.

Seeds are multicellular with embryo + food reserve, have a protective seed coat, and store more nutrients; spores are single-celled with minimal reserves.

What does the term "gymnosperm" literally mean?

"Naked seed" – seeds are exposed on cone scales, not enclosed in ovaries.

Define "angiosperm."

A flowering plant whose seeds are enclosed within a mature ovary (fruit).

Are all seed plants heterosporous or homosporous?

Heterosporous.

What two spore types do seed plants produce?

Microspores (→ pollen/male gametophyte) and megaspores (→ female gametophyte/ovule).

Which gymnosperm phylum contains conifers?

Coniferophyta.

Why do many conifers secrete resin?

To protect against insects and fungal pathogens.

Distinguish between monoecious and dioecious.

Monoecious plants bear male and female cones on the same individual; dioecious plants have separate male and female individuals.

Are pine trees monoecious or dioecious?

Monoecious.

Where are microsporangia located in pines?

On the underside of male cone sporophylls.

What is produced when a microsporocyte undergoes meiosis in a pine?

Four haploid microspores → pollen grains (male gametophytes).

How many cells does a mature pine pollen grain contain before germination?

Four cells: a tube cell, generative cell, and two that degenerate later.

What structures provide buoyancy for pine pollen in wind?

Two large air sacs on the pollen grain.

What does a megasporocyte in a pine cone produce after meiosis?

Four megaspores; usually only one survives to form the female gametophyte.

What is an ovule in gymnosperms?

A megasporangium plus its integuments housing the female gametophyte and egg.

Describe pollen tube function in pines.

It grows from pollen grain through megasporangium to deliver non-motile sperm to the egg.

What tissues nourish a developing pine embryo inside the seed?

Haploid female gametophyte tissue.

How are pine seeds often dispersed?

By wind, aided by a papery wing on the seed coat.

Give two ecological roles of conifer forests.

Provide habitat/food for animals and prevent soil erosion with extensive roots.

Which gymnosperm phylum comprises palm-like cycads?

Cycadophyta.

Are cycads monoecious or dioecious?

Dioecious with separate male and female plants.

What primitive feature do cycad sperm cells retain?

Flagella for motility.

Name the single living species in Ginkgophyta.

Ginkgo biloba (maidenhair tree).

Why are female Ginkgo seeds considered unpleasant?

Their fleshy seed coat emits a foul odor when mature.

Which gymnosperm phylum includes Ephedra and Welwitschia?

Gnetophyta.

What specialized water-conducting cells do gnetophytes share with angiosperms?

Vessel elements.

Which compound derived from Ephedra is pharmaceutically important?

Ephedrine, a stimulant increasing heart rate and blood pressure.

How many cotyledons are found in monocot embryos?

One.

List three distinguishing features of dicot plants.

Flower parts in 4s/5s, netted leaf venation, vascular bundles arranged in a ring, two cotyledons, often show secondary growth.

What are the collective terms for calyx and corolla?

Perianth (calyx = sepals, corolla = petals).

Name the male reproductive organ of a flower.

Stamen, consisting of filament and anther.

What female floral structure contains the ovary, style, and stigma?

Carpel or pistil.

Where does microsporogenesis occur in angiosperms?

Inside anther microsporangia producing microspores → pollen grains.

How many megaspores survive in an angiosperm ovule after meiosis?

Typically one out of four; it forms the embryo sac (female gametophyte).

What is double fertilization?

One sperm fertilizes the egg (forming zygote), another sperm fuses with two polar nuclei to create triploid endosperm.

What tissue nourishes the angiosperm embryo?

Endosperm (usually triploid, 3n).

After fertilization, what does the ovary wall become?

Fruit (pericarp).

What develops into the seed coat of a flowering plant?

Integuments plus embryo sac wall and nucellus.

Which part of a pollen grain forms the pollen tube?

The tube cell.

What type of cell division forms microspores and megaspores?

Meiosis.

Which small green structures carry out photosynthesis in whiskferns and horsetails?

Green stems; whiskferns lack leaves, horsetail stems are photosynthetic.

Define "prothallus."

The heart-shaped, photosynthetic gametophyte of ferns arising from a spore.

What is the function of elaters or pseudoelaters in hornwort spores?

They aid spore dispersal by twisting as they dry.

Which moss compound slows decay and preserves remains in peat bogs?

Phenolic compounds in cell walls of Sphagnum.

Why can vascular plant roots allow shoots to grow taller?

They anchor plants and efficiently absorb water/nutrients to support taller growth.

Name an example species of horsetail.

Equisetum arvense.

What is a strobilus?

A cone-like cluster of sporophylls bearing sporangia (seen in horsetails, club mosses, some ferns, and gymnosperms).

Which embryonic structures are found inside a seed?

Embryonic root (radicle), shoot (plumule), and cotyledon(s).