Question | Answer |
Types of spines in flowering plants | Spines with vascular tissue and Spines without vascular tissue. |
Two types of spines with vascular tissue | Superficial attachment and Deep attachment. |
Spines with vascular tissue with a superficial attachment | Stem (Originates from leaf axil), Leaf (originates below bud) and Stipular (In pairs, originates next to the leaf). |
Spines with vascular tissue with a deep attachment | Root spine (No accompanying structures) |
What are the three different methods of description (diagrams) for plants? | Life diagram, stick diagram and ground diagram |
Basal-dicots | Basal Angiosperms. The Basal Angiosperms are comprised of a separate lineages that branched off from other flowering plants at successive occasions before the appearance of the "true" dicots (Eudicots) in the fossil record. |
Monocots | Monocotyledons, commonly referred to as monocots, are flowering plants whose seeds typically contain only one embryonic leaf, or cotyledon. Flowers parts tend to be in multiples of 3. |
Eu-dicots | The eudicots, Eudicotidae or eudicotyledons are a monophyletic clade of flowering plants. Typically containing two cotyledons (seedling leaves). Flower parts tend to be in multiples of 4/5. |
What are the difference in the vascular tissue in Monocots and Eu-dicots? | For monocots the vascular system spreads throughout the stem without any diameter growth and tend to grow bushy roots. Whereas Eu-dicots' vascular tissue ring around the stem and has diameter growth with roots that contains main and side roots. |
What are the difference in the leaves in Monocots and Eu-dicots? | Leaves of monocots tend to be attached around the stem (no petiole) with parallel venation. Leaves of Eu-dicots have petioles and branching venation. |
What are the difference in the pollen grains in Monocots and Eu-dicots? | Monocots have pollen grains with 1 opening each (monosulcate), while Eu-dicots have pollen grains with 3 openings each (mostly tricolpate). |
Meristem | A region of plant tissue, found chiefly at the growing tips of roots and shoots and in the cambium, consisting of actively dividing cells forming new tissue. |
Where are the two major Meristems structures? | Shoot tips (shoot apical Meristems) and Root tips (root apical Meristems). |
Bud | In botany, a bud is an undeveloped or embryonic shoot and normally occurs in the axil of a leaf or at the tip of a stem. It is also an apical meristem in resting stage, which is protected by scale leaves |
What are the leaf zones in leaf morphology? | Lower and Upper leaf zones |
Lower leaf zone | Generally forms most of the leaf. |
Upper leaf zone | Generally remains undeveloped as a leaf tip (precursor tip). |
What are the leaf shapes in leaf morphology? | Simple and compound. |
Pinnate | Leaflets arranged on either side of the stem, typically in pairs opposite each other. |
What are the leaf symmetry in leaf morphology? | Asymmetry varies between species and sometimes within species. Asymmetry may be precise or imprecise as each leaf is unique. Usually occuring at the base of the leaf. |
Leaf polymorphism/heterophylly | Variability in leaf shape and size. |
Leaf dimorphism | Plants with two distinct types of leaves. |
Leaf anisophylly | Two leaves of different shape or size occurring at the same node. |
Heteroblastic series | A changing progression of leaf shapes along a shoot (often present in seedlings). |
Cambium | In botany, is a tissue layer that provides partially undifferentiated cells for plant growth. It forms parallel rows of cells, which result in secondary tissues. |
Types of Meristems | Primary growth (Apical meristem) & Secondary growth (Vascular cambium & Cork cambium). |
Bryophytes | Embrophytes; non-vascular land plants and phylogenetically an informal group. They have alternation of generations, a dominant gametophyte, antheridia and archegonia. |
Embroyophytes | The Embryophyta are the most familiar group of green plants that form vegetation on earth. Living embryophytes include hornworts, liverworts, mosses, ferns, lycophytes, gymnosperms and flowering plants, and emerged from Charophyte green algae. |
Where are the sporophytes of Bryophytes? | Attached to the gametophyte. |
Are the spores of the mother cell (sporocyte) haploid or diploid? | Spores are haploid are produced through meiosis. |
Archegonia | The female sex organ that produces the egg. They are flask-shaped structures with a long neck. The egg is at the canal bottom which is initially blocked by neck canal cells, which break down once the eggs is ready for fertilization. |
Antheridia | The male sex organ that produces the sperm. |
3 groups of Bryophytes | Liverwort (Phylum Hepatophyta), Hornworts (Phylum Anthocerophyta) and Mosses (Phylum Bryophyta). |
Hepatophyta Gametophytes | Two types: Thalloid liverwort and Leaf liverwort. |
Gametophytes of Thalloid liverworts | Body plant thallose, without distinct stem or leaves, flat sheet of tissue. |
Gametophytes of Leafy liverworts | Main plant body is foliose with distinct axes (stems) and leaves. |
Do Talloid liverworts and Leafy liverworts have roots? | No, they are anchored to the substrate by unicellular rhizoids. |
Structure of liverworts thalloid (Upper surface) | Simple, and often undifferentiated mass of tissue. Upper surface consists of tissue and many chloroplasts. The upper surface is a thin cuticle, hence they are restricted to damp areas. They also have spores to help with gas exchange. |
Structure of liverworts thalloid (Lower surface) | The lower surface has rhizoids and thin scales. |
Rhizoids | A filamentous outgrowth or root hair on the underside of the thallus in some lower plants, especially mosses and liverworts, serving both to anchor the plant and (in terrestrial forms) to conduct water. |
Liverwort leaves | Simple. The stem is parenchymatous (The basic tissue of plants). Leaves are one cell thick without cuticle. Normally arranged in two lateral rowiths with another row of smaller leaves (underleaves/amphigastria) on the ventral surface. |
2 types of lateral leaf arrangement dependant on the insertion of leaves | Incubous leaves and Succubous leaves. |
Incubous leaves | The front edge of each leaf overlaps the one in front (towards the apex). |
Succubous leaves | The front edge underlies the back edge of the leaf in front (towards the apex). |
Gemmae (gemma) | Special asexual reproductive bodies. They are little balls of cells which can grow into new plants when they detach off parent. They may be in gemma cups (in thalloid types) or on the ends of branches in leafy liverworts & mosses. |
Structures of a mature sporophyte | A foot, embedded in gametophyte, absorbs water & nutrients. A seta (stalk) which raises the top of the sporophyte out of the archegonium. Capsule or sporangium, contains spore mother cells (divided by meiosis: haploid spores) and Elaters. |
Elaters | A thick elongated cell which helps spores get out of the capsule in sporophytes. |
Anthocerophyta hornworts | The name refers to the shape of sporophyte which looks like a horn. Gametophyte is a flat thallus. It is usually lobed and doesn't branch, often a deeper green color. |
Anthocerophyta sporophye structures | A foot which absorbs nutrients from gametophyte. No seta (stalk), but instead a meristematic region above the foot which divides so that the sporophyte can keep on elongating by growth at the base. |
Type of growth of Anthocerophyta | Indeterminate: no fixed and final size for indeterminate growth. |
The sporophytes of anthocerophyta are green, can they photosynthesise? | Yes, the wall of the sporophyte also has stomata for gas exchange. |
Bryophyta mosses | Largest group of bryophytes that shows an alternation generations (gametophyte-sporophyte) |
Structure of moss gametophytes | Consists of a stem with lateral leaves. Multicellular rhizoids anchor the plant to the substrate. The stem may be upright with the sporophyte at the end of the main stem (acrocarpous). |
Hydroids | A type of vascular cell that occurs in certain bryophytes. In some mosses, hydroids form the innermost layer of cells in the stem. At maturity, they are long, colourless, thin walled cells of small diameter, containing water but no living protoplasm. |
Protonema | Filament of chlorophyllous cells that looks like algae. Buds form at intervals on the protonema and these grow into the adult gametophytes. |
Acrocarpous | Mosses having clustered upright stems and the reproductive parts borne at the tip of a stem, commonly the main stem. |
Pleurocarpous | Mosses having mainly horizontal trailing stems and the reproductive parts borne laterally. |
Leptoids | A type of elongated food-conducting cell in the stems of some mosses. They surround strands of water-conducting hydroids. |
Dioecious | A plant having the male (antheridia) and female (archegonia) reproductive organs in separate individuals. |
Monoecious | A plant having both the male and female reproductive organs in the same individual; hermaphrodite. |
Monophyletic | A group of organisms descended from a common evolutionary ancestor or ancestral group, especially one not shared with any other group. |
Synapomorphies | A characteristic present in an ancestral species and shared exclusively (in more or less modified form) by its evolutionary descendants. Defined on the basis of shared derived characters. |
Charophyceans | A class of charophyte green algae. They are the closest relatives to the embryophytes. |
Embryophytes' five key synapomorphies | Apical meristems, Alternation of generations, walled spores produced in sporangia, multicellular gametangia & multicellular, dependant embryos. |
Gametangium | A specialized organ or cell in which gametes are formed in algae, ferns, and some other plants. |
Sporopollenin | One of the most chemically inert biological polymers. It is a major component of the tough outer (exine) walls of plant spores and pollen grains. It is chemically very stable and is usually well preserved in soils and sediments. |
Embryophytes male gametangia (antheridium) produces? | Each antheridium usually produces lots of flagellate sperm that swims to the eggs in the archegonia through a film of water. |
Homosporous life cycles | Where the spores produced are all the same, and grows into the same sort of gametophyte with both male and female gametangia. |
Heterosporous life cycles | Where two sorts of spores are produced by the sporophyte in different sporangia. Large spores (megaspores) grow into female gametophytes (archegonia) while smaller spores (microspores) grow into male gametophytes (antheridia). |