Exam 2: Fungi and Plant
Terms in this set (58)
Describe the role of fungi in global nutrient cycles?
Fungi are heterotrophs which break down organic detritus releasing nutrients for plants and other organisms
Describe the nutritional strategies seen in fungi
heterotrophic including parasites, pathogens, mutalistic symbionts, detritivores
Uses of fungi by humans
production of antibiotics to kill and inhibit bacteria, fermentation to produce beer and wine, use in production of bread, cheeses and soy sauce
Lichens are a mutualistic association between...
fungi and algae or cyanobacteria
How would you recognise the reproductive parts of a basidiomycete fungus?
the reproductive 'fruiting body' looks like a mushroom or toadstool above the ground
what is the correct definition for plasmogamy in fungi?
fusion of hyphae and cytoplasm of different individuals, but not the nuclei
Describe common steps in fungal life cycles?
fusion of hyphal tips, resulting in dikaryotic cells, followed by fusion of nuclei to give a diploid zygote
true about asexual reproduction in fungi
Many fungi have both sexual and asexual parts of their life cycle, and some species seem to only reproduce asexually
the athlete's foot fungus is only known to reproduce asexually via what?
Fungi are most closely related to...
Whats true about mycorrhizae?
Mutualistic association between some fungi and >90% of plants which provides benefit to both organisms: the fungi get food (produced through photosynthesis) from the plant, and in exchange, provide nitrogen, phosporus and other mineral nutrients from the soil
What habitat is a perennial evergreen plant with narrow needle-like leaves with waxy covering likely to inhabit?
Taiga (boreal forests)
Which kind of life cycle is typical of most animals?
Which life cycle is found in ferns?
alternation of generation
What conclusion is supported by plant phylogenies (evolutionary trees)?
The oldest lineages of land plants are descended from some green algae (Charophytes)
Solving the problem of the need for water in plant reproduction, which restricted plants to moist environments, was a major breakthrough in plant evolution. In what major group of plants did this first occur?
Plants need to take in carbon dioxide from the atmosphere and release oxygen, but the waxy cuticle overlaying the epidermis of stems and leaves to prevent water loss also prevents the exchange of gases. What structure found in many plants was the solution to this problem?
stomata: The stomata consist of an opening surrounded by specialized guard cells. When the guard cells become taut, they open the pore, maximizing carbon dioxide intake and release of oxygen.
The fossil record is important to our understanding of plant evolution. The oldest plant fossil dates to 475 million years ago, and the fossil record for land plants spans almost 60 million years, documenting the origin of land plants. What fossilized remains were found early in the record that helped plants adapt to land by reducing water evaporation?
sheets of waxy material called cuticle
Mosses, ferns, and clubmosses expand their geographic range by spore dispersal. What replaces spore dispersal in gymnosperms and angiosperms?
In the alternation of generations life cycle (e.g. ferns), the sporophyte produces what?
In the alternation of generations life cycle, meiosis directly precedes the production of what?
spores: spores germinate into the gametophyte (Prothallus) which produces the gametes via antheridia and archegonia
In the alternation of generations life cycle, mitosis directly precedes the production of what(2)?
eggs/sperm, and gametes
The reason that mitosis can result in the production of haploid gametes in alternation of generations is because
Eggs and sperm are produced by the haploid gametophyte via mitosis
In the fern life cycle, how does fertilization occur?
The gametophyte produces sperm and eggs in gametangia (antheridia and archegonia). The sperm reach the eggs by swimming through water
he earliest land plants were most likely to have lived in which of the following habitats?
Fresh Water WetLands
What is heterospory?
The production of two kinds of spores: the larger spores germinate into female gametophytes, the smaller spores germinate into male gametophytes
In the life cycle of mosses, what is true of the sporophytic generation and the gametophytic tissue?
The sporophytic generation grows out of gametophytic tissue and is dependent on the green gametophyte for nutrition
Which of the following innovations in seed plants did away with the need for water to effect fertilization?
What innovations allowed plants to move into drier habitats?
embryo packaged in a seed, pollen, vascular tissue:: The embryo is protected from desiccation (drying out) by the seed, pollen replaces the need for fertilization via water, cuticles also protect the earliest land plants from desiccation and vascular tissue allows water to be provided to aerial parts
Large spreading leaves, epiphyitc habit, lianas are adaptations found in what type of plant? (from where)
tropical rain forests plants so they can collect enough sun light
What is the best reason that tundra ecosystems do not support large trees
There is only a shallow layer of thawed soil to support roots--little support options for trees which need deep roots to for structural stability, and little options for uptake of water (and nutrients) when the water is frozen in permafrost
explain the purpose of flowers?
Flowers are adaptations that increase the probability that pollination will occur:: Flowers have many adaptations to ensure pollination. Among them is showy petals (or other floral parts), scent, nectar, and special markings to direct the pollinator to the interior of the flower. Plants that are pollinated by wind tend not to be showy, but do have characteristics that aid in the dispersal of pollen
Explain the pollination process of flowering plants?
The pollen grains germinate on the stigma and grow down the style to reach the egg contained within the female gametophyte (inside the ovule), The egg contained within the female gametophyte is fertilized by a sperm cell contained within the male gametophyte, Pollinators pick up pollen grains from the flowers stamens and move them from flower to flower.
What adaptation found in vines and epiphytes aid in the capture of light for photosynthesis?
They take advantage of the structural support of trees to reach high in the canopy, where light levels are higher
What is a prime characteristic of both the gymnosperms and angiosperms?
What are some major evolutionary innovations found mainly in the angiosperms?
fruit, flowers, double fertilization
what are tracheids? (xylem cells)
tracheids are xylem cells found in all seed plants (gymnosperms and angiosperms) and thus are important for conducting water from roots to aerial tissues.
What is a major cell type that is totipotent?
parenchyma, which is capable of cell division thru its whole life
What are sieve tube members?
Phloem tissues move sugar-laden sap from leaves to roots and other tissues, including growing leaf buds and flowers.(They conduct photosynthate (sugars) throughout the plant)
Why is seed dormancy advantageous for many plants?
Plants can hold off on germination until environmental conditions are ideal for growth of the new seedling
list some gymnosperms plants
cycads, conifers, gnetophytes (Welwitschia, Ephedra, and Gnetum)
What is a true statement about life cycles as we "go up" the plant evolutionary tree (i.e. from oldest to most recently evolved)?
-Primitive non vascular land plants are gametophyte dominant with a dependent sporophyte
-seedless vascular plants have alternation of generation (independent free-living sporophytes and gametophytes)
-seed plants have dominant sporophytes with a dependent gametophyte
-transition from haploid dominant in algae, mosses, to half/half in ferns and diploid dominant in the seed plants
In angiosperms, how is the female gametophyte formed?
A megaspore mother cell (megasporocyte) in the ovule undergoes meiosis to produce a megaspore which in turn develops by mitosis into a seven celled, eight nucleate female gametophyte
When can you encounter monoecy and dioecy in flowering plants?
When plants have unisexual flowers (containing only stamens or only carpels but not both together)
What plant cell types have thick secondary walls?
sclereids and fibers
What is the main function of xylem?
moving water and dissolved nutrients from roots to shoots in the plant
The vascular tissue, phloem, is made up of:
sieve tube members and companion cells, the phloem cells are alive at maturity and the sieve tube conducting cells have a companion cells which helps regulate movement of solutes, and provide energy.
What organs have apical meristems?
Roots and Stems, apical meristems are found at the root tip and shoot tip and help elongate the plant in both directions
What is the apical meristem?
The area at the apex of a stem or root that has parenchyma cells that continually divide, producing growth in length.
What is an imperfect flower?
A flower that is missing either stamens or carpels
A fruit can be described as what?
a ripened carpel (female reproductive system)
List 4 plant cell type
Describe parenchyma plant cells
"workhorse cells" least specialized, primary thin walls, alive at maturity, Functions: Metabolism, Photosynthesis, Starch storage, fleshy part of fruit, regeneration of more specialized cells in case of damage- TOTIPOTENT (Stem Cells)
Totipotent Cells are known as
plant stem cells
Describe Collenchyma plant cells
Thick primary cell walls, grouped as cylinders, can elongate and expand stem and leaf growth, Alive at maturity, Function: flexible support for herbaceous and young woody plants
Describe Sclerenchyma plant cells
thick secondary wall, strengthen lignin, CANNOT ELONGATE growth, often lack protoplast= DEAD at maturity, Function: Support
-Contians: Fibers, Sclereids(stone cells- hard seed coat or nut shell), Dermal tissue: Epidermis=single layer tightly packed cells, Cuticle= waxy coating secreted by epidermis of leaves to son serve water, root hairs= specialize epidermis ells for water and mineral absorption
Describe the Vascular Tissue System of Plants
Continuous system from too tips to leaf buds, Stele containing- Xylem and phloem.
Xylem= Tracheids and Vessel Elements (Gymnosperm and Angio) Water transport system
Phloem= Sieve Tube Members&Companion Cells )Food congaing cells
angiosperms are what type of life cycle?