Plant Kingdom Review

Flashcards covering the classification and characteristics of the Plant Kingdom, including Algae, Bryophytes, Pteridophytes, Gymnosperms, and Angiosperms based on Chapter 3 lecture notes.

How did Whittaker (1969) classify the five kingdoms?

Monera, Protista, Fungi, Animalia, and Plantae.

Which organisms with cell walls were previously in Plantae but are now excluded?

Fungi, and members of the Monera and Protista.

Which group does Cyanobacteria (blue green algae) belong to according to modern understanding?

They are no longer considered algae and are excluded from the plant kingdom.

What was the basis of the 'Artificial' system of classification given by Linnaeus?

It was based on gross superficial morphological characters such as habit, colour, number and shape of leaves, or on the androecium structure.

Which classification system consider both external and internal features like ultrastructure, anatomy, embryology, and phytochemistry?

Natural classification systems, such as the one given by George Bentham and Joseph Dalton Hooker.

What is phylogenetic classification based on?

Evolutionary relationships between various organisms, assuming organisms in the same taxa have a common ancestor.

What is Numerical Taxonomy?

A system carried out using computers based on all observable characteristics, where numbers and codes are assigned to all characters and data are processed.

How is Cytotaxonomy defined?

Classification based on cytological information like chromosome number, structure, and behaviour.

What defines Chemotaxonomy?

The use of the chemical constituents of the plant to resolve classification confusions.

What are the general characteristics of Algae?

Chlorophyll-bearing, simple, thalloid, autotrophic, and largely aquatic (fresh water and marine) organisms.

What are examples of colonial and filamentous algae?

Colonial: Volvox; Filamentous: Ulothrix and Spirogyra.

What is the difference between isogamous, anisogamous, and oogamous reproduction in algae?

Isogamous involves fusion of gametes similar in size; anisogamous involves fusion of gametes dissimilar in size; oogamous involves fusion between one large non-motile female gamete and a smaller motile male gamete.

Which marine algae produce hydrocolloids used commercially?

Algin (from brown algae) and carrageen (from red algae).

What is Agar obtained from and what are its uses?

Obtained from Gelidium and Gracilaria; used to grow microbes and in preparations of ice-creams and jellies.

Which unicellular alga is used as a food supplement by space travellers?

Chlorella, which is rich in proteins.

What are the common name, major pigments, and stored food of Chlorophyceae?

Common name: Green algae; Major pigments: Chlorophyll $a, b$; Stored food: Starch (in pyrenoids).

What is the cell wall composition of Chlorophyceae?

An inner layer of cellulose and an outer layer of pectose.

What are the common name, major pigments, and stored food of Phaeophyceae?

Common name: Brown algae; Major pigments: Chlorophyll $a, c$ and fucoxanthin; Stored food: Mannitol or laminarin.

What are the three parts of the plant body in brown algae (Phaeophyceae)?

Holdfast (attachment to substratum), stipe (stalk), and frond (leaf-like photosynthetic organ).

What are the common name, major pigments, and stored food of Rhodophyceae?

Common name: Red algae; Major pigments: Chlorophyll $a, d$ and $r-phycoerythrin$; Stored food: Floridean starch.

Why are Bryophytes called 'amphibians of the plant kingdom'?

Because they can live in soil but are dependent on water for sexual reproduction.

What are the male and female sex organs of Bryophytes called?

The male sex organ is the antheridium (produces biflagellate antherozoids) and the female sex organ is the archegonium (flask-shaped, produces one egg).

What is the economic and ecological importance of Sphagnum?

It provides peat used as fuel and as a packing material for trans-shipment due to its water-holding capacity; it also helps colonise rocks.

What are the two stages of the moss gametophyte life cycle?

The first stage is the protonema (creeping, green, filamentous) and the second stage is the leafy stage (upright, slender axes bearing spirally arranged leaves).

What distinguishes Pteridophytes evolutionarily from other plants?

They are the first terrestrial plants to possess vascular tissues (xylem and phloem).

What is the difference between homosporous and heterosporous pteridophytes?

Homosporous plants produce spores of similar kinds, while heterosporous plants (like Selaginella and Salvinia) produce macro (large) and micro (small) spores.

What is the precursor to the seed habit in evolution?

The development of the zygote into young embryos within the female gametophytes (retained on parent sporophytes), as seen in heterosporous pteridophytes.

What defines Gymnosperms (naked seeds)?

Plants where ovules are not enclosed by any ovary wall and remain exposed both before and after fertilisation.

Describe the root associations in Pinus and Cycas.

Pinus has fungal association (mycorrhiza), while Cycas has coralloid roots associated with $N_2$-fixing cyanobacteria.

What is the male gametophyte in gymnosperms called?

The pollen grain, which is highly reduced and confined to a limited number of cells.

What are the two classes of Angiosperms?

Dicotyledons and monocotyledons.

What are the size extremes mentioned for Angiosperms?

Range from the smallest Wolffia to the tall Eucalyptus which can reach over $100\,m$.