Botany
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Template:EventLinksBox Botany is a Division B and Division C event that was first run as a trial event in 2020 at New Jersey regional tournaments. It was also scheduled to be run at the 2020 Virginia and Hawaii state tournaments, but these tournaments were cancelled due to the 2019-20 Coronavirus outbreak. The event is run as an exam, focusing on plant biology and horticulture. Each participant may bring one 8.5" x 11" note sheet with information on both sides, as well as one stand-alone non-programmable, non-graphing calculator.
Plant Anatomy and Morphology
Vascular Plants
The morphology of vascular plants have two key parts: the shoot system (what sprouts above ground, which are the stem and leaves) and the root system (what grows underground). Both systems depend on each other to function, as the shoot system needs the root system for water and minerals and the root system needs the shoot system for food and energy. If a plant loses one of the systems, it can regrow. Among the many tissues and organs, vascular plants have 4 main organ systems: the stem, the roots, the leaves, and the reproductive organs. The stem holds the leaves and connects them to the roots through two tissues called the xylem and phloem. The roots hold the plant in place and absorb water and nutrients from the ground. The leaves grow from the stem and their purpose is to photosynthesize. The shape and structure of a leaf depends on the plant itself. The reproductive organs allow the plant to multiply in number, both asexually and sexually depending on the plant.
Reproduction
Non-vascular plants (bryophytes)
- Moss:
- Dispersal- Spores are dispersed into favorable environments such as moist soil or tree bark, where they may germinate and grow into haploid gametophytes (gamete-producing plant structure).
- Protonemata- Promising spores develop a mass of green, branched, one-cell-thick filaments called protonemata. Protonemata have large surface areas that enhance water and mineral absorption to continue germination. Haploid.
- Budding- Buds are plant structures that give rise to gametophytes. These are produced by the haploid protonemata through mitotic division.
- Male gametophyte- Contains inner structures known as gametangia, more specifically, antheridia, where sperms are produced and kept.
- Female gametophyte- Contains inner structures known as gametangia, more specifically, archegonia, where eggs are produced and kept.
- Fertilization- Upon favorable conditions, the flagellated sperm swim through a film of water toward eggs (produced by female gametangia).
- Zygotic Stage- A diploid zygote develops inside of the archegonium and develops into a sporophyte embryo.
- Sporophytic Stage- A young diploid sporophyte grows a long stalk (seta), again from the nutrient-dependent archegonium.
- Maturity- Looking at the entire plant, the mature sporophyte is on top (seta + capsule), and attached by the foot of the female gametophyte.
- Repetition in due time- Meiosis occurs inside of the capsule (sporangium) where haploid spores develop. Upon capsule maturity, the lid pops off, and the spores are released to repeat the preceding steps.
Vascular plants
- Gymnosperms
- Angiosperms
Evolution and Paleo-Botany
Major Plant Groups
Algae vs. Multicellular Plants
Monocots vs. Dicots
If an organism reproduces via enclosed seeds, it is either a monocot or a dicot. The terms "monocot" and "dicot" refer to the number of cotyledons present in the seed. A monocot (monocotyledon) has only one cotyledon, and dicots (dicotyledon) have two. Monocots and dicots are also differentiated by their leaf venation (leaf vein structure), stem structure, root systems, and floral patterns.
Leaf venation
- Monocots have parallel leaf veins.
- Dicots have branching leaf veins.
Stem structure
- Monocots develop vascular bundles in groups that are placed arbitrarily around the stem.
- Dicots develop vascular bundles in groups that form a ring around the edge of the stem.
Root systems
- Monocots usually grow with a fibrous root system, meaning that there are many small roots that branch out from each other.
- Dicots usually grow a taproot, which is a deep and thick central root in which smaller roots branch out from.
Floral patterns
- Monocots usually flower in groups of 3
- Dicots usually flower in groups of 5
Embryophytes vs. Cryptograms
Embryophytes and Cryptogams are 2 large groups of plants. The term "plant" is a very general term in many ways and is used commonly to describe most organisms that aren't animals. Embryophytes are a clade of plants commonly associated with land plants, like trees, mosses, and flowering plants, while Cryptogams are a group that includes plants that reproduce with spores, such as fungi, algae, and mosses.
Embryophytes are classified by their ability to nurture the young sporophyte inside the tissue of the gametophyte. This includes groups such as nonvascular plants (mosses, liverworts, and hornworts), seedless vascular plants (such as ferns and lycophytes), gymnosperms (like coniferous trees and cycads), and angiosperms (flowering plants).
In contrast, Cryptograms are organisms that reproduce without seeds or flowers, with the use of spores. This includes groups such as thallophytes (such as fungi, bacteria, and algae), bryophytes (nonvascular plants), pteridophytes (seedless vascular plants).
Woody Plants vs. Herbaceous Plants
Botany
Horticulture
Plant Biochemistry
Energy and Nutrient Cycles
Genetically Modified Organisms
Plant Diseases
Nutrient Deficiencies
Resources
- Science Olympiad Trial Event Rules
- 2020-2021 UT Invitational Botany Examination: https://scioly.org/forums/viewtopic.php?f=294&p=429503#p429503