Test 2 P2 Flashcards
What are the functions of protists in an ecosystem?
- Primary producers in oceans & lower in food chain, supporting subsequent trophic levels.
- Parasitize plants
- Can act as decomposers & can cause disease
How do protists move? What 3 parts?
- Cilia (short hair)
- Pseudopods (arm, mouth-like projection)
- Flagellum (long hair-like appendage)
How do ferns reproduce?
Releases spore & must land on suitable surface, such as moist, protected area to germinate & grow into gametophytes. Fertilization –> Sporophyte (diploid, 2n) –> Meiosis –> Gametophyte (haploid, 1n)
What are the main parts of a fern & function? (3)
- Rhizome: underground stem
- Fronds: leaves
- Sporangia: reproductive structures (brown dots on fronds)
What are the 2 main phyla of plants?
- Lycophytes: club & spike mosses, quillworts. Sporophyte –> sporophylls
- Monilophytes: Ferns/whisk ferns, horsetails. Damp environments like marshes. Most advanced seedless plant (fern)
What are the 3 main phyla of bryophytes?
- Mosses: most numerous of non-vascular plants. Warmer climates.
- Liverworts: have gemmae that have asexual spores. Flat leaves for movement of gasses.
- Hornworts: pipe-like sporophyte, stomata, need moisture
Describe pollen grains
Are male gametophytes distributed by wind, water, or animals. Protected from drying out, can reach female organs w/o water. After reaching female gametophyte, creates a tube that delivers male nucleus to egg cell.
How does gymnosperm reproduction occur?
Alternation of generations. For ex. In conifers, leafy green part is sporophyte; cone contains male & female gametophytes. Male cones located in lower part of tree & pollen blows into upper branches to fertilize female cones. Male gametophyte splits into 2 sperm nuclei, one fuses w/ egg. Diploid zygote formed, divides by mitosis to form embryo. No fruit since seeds have no covering.
What are the structures of gymnosperms?
2 conducting tissues: xylem & phloem
1. Xylem: conducts water & minerals from roots to rest of plant & provides structural support. Helps plants grow taller, 1 way flow
2. Phloem: transports sugars, proteins & other molecules. 2 way flow
What are the 3 plant stem tissue types?
Ground, vascular, dermal
What are ground plant stem tissues?
made mostly of parenchyma cells; pith towards interior, cortex b/w pith & epidermis
What are vascular plant stem tissues?
made of xylem & phloem in bundles running up & down stem; xylem made of tracheid & vessel elements, phloem made of sieve-tube & companion cells
What are dermal plant stem tissues?
protects underlying tissues; epidermis is single layer of cells that contains stomata surrounded by guard cells; trichomes are hair-like structures
What are the 3 root zones?
- Zone of cell division: tip of root where most cell division takes place at apical meristem.
- Zone of elongation: newly formed cells increase in length, lengthening the root.
- Zone of cell maturation: cells differentiate into specialized cell types - root hairs start to appear here
What are the 4 main kinds of root types?
Tap, fibrous, aerial & prop, epiphytic
What are tap roots?
main root that grows down; penetrates deep into soil. Better in dry areas
What are fibrous roots?
closer to soil surface, forms dense network & helps prevent soil erosion. Found mainly in monocots, better in wet areas
What are aerial & prop roots?
above ground roots (adventitious roots)
What are epiphytic roots?
allow a plant to grow on another plant
What are the 4 main parts of a leaf & what do they do?
- Cuticle: reduces water loss from leaf surface.
- Epidermis: has guard cells/stomata for gas exchange.
- Mesophyll: has chloroplasts, photosynthesis occurs here.
- Vascular bundles on leaf to transport water & minerals. (xylem & phloem)
- Monocots have parallel venation
- Dicots have net-like
- Gingko has dichotomous
What are some adaptations of leaves?
- Aquatic plants have wide leaves to float.
- Cacti leaves reduced to spines to conserve water.
- Conifers have small needle-like leaves to limit water loss.
What is photomorphogenesis, a plant sense?
response to light, including photoperiodism (track time) & phototropism (grow towards or away from light). Response mediated by photoreceptors. Auxins are hormones that elongate cells
What is gravitropism, a plant sense?
response to gravity. Growth of shoot upwards is negative & downwards growth is positive. Accomplished w/ amyloplasts or statoliths - have starch granules that settle down in response to gravity
What are the 5 main plant hormones?
Cytokinin, gibberellins, abscisic acid, ethylene, auxins
What are auxins, plant hormone?
Hormones that elongate cells
What is cytokinin, plant hormone?
promotes cell division & bushier growth
What is gibberellins, plant hormone?
stimulate shoot elongation, seed germination along w/ fruit & flower maturation
What is abscisic acid?
causes abscission, induces dormancy in seeds
What is ethylene?
associated w/ fruit ripening, flower wilting & leaf fall
What are the 3 kinds of plant responses to touch?
thigmotropism, thigmonastic, thigmomorphogenesis
What is a thigmotropism response in plants?
movement subjected to constant directional pressure (plant tendrils wrap around a support structure)
What is a thigmonastic response in plants?
response independent of direct stimulus. Ex. venus flytrap
What is a thigmomorphogenesis response in plants?
slow developmental change in shape due to continuous mechanical stress. Ex. trees in windy area may grow trunk & branches away from direction of wind
What are the 2 main kinds of plant tissue types?
Meristematic & non-meristematic or permanent tissue
What is meristematic tissue?
Continues to divide & grow. Found in apical or lateral meristems.
What are non-meristematic or permanent tissues?
No longer actively dividing
What are apical meristems?
Ends of root or shoot tip that grow up & down responsible for primary growth
What are lateral meristems?
sides of plant that increase girth of plant responsible for secondary growth
What is phyllotaxy & what are the 4 kinds?
Arrangement of leaves on a stem. Alternate, spiral, opposite, whorled
