chapters 21, 25, 26 Flashcards
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the location in plants where sugar originates
sink
the places in the plants where sugars are unloaded
what do carnivorous plants obtain by eating their prey?
nitrogen
cation takes place between
soil and roots
phloem
the plant vascular tissue that carries organic nutrients
benefits of having humus in soil
decreases rain runoff, retains positively charged minerals, aerates soil, increases the benefits of fungi and bacterial decompostion
guard cells
the cells that bulge to open stoma during he day, and shrink to close the stoma at night
casparian strip
the layers of the impermeable lignin and suberin bordering four sides of the root endodermal roots cells that forces water to move into the endodermal cells rather than between
tracheids
conducting cells that are tapered at both ends
water potential
a measure of the capacity to release or to take up water, determined by water pressure and osmotic pressure
gibberellins
plant hormones was discovered in infected rice seedlings that grew extremely tall and slender with “foolish seedling disease”
ions is associated with auxin and used during signal transduction that causes a plant to bend towards a light sources
H+
How does gibberellin actually work
It attaches to a plasma membrane receptor and results in gene activation to produce the enzyme amylase that releases sugars for additional cell growth, division, and elongation.
gibberellin
A chemical messenger from the embryo that stimulates a seed to digest the endosperm
auxin
plant hormone produced in apical meristems inhibits the growth of axillary buds
ethylene
plant hormones stimulates the ripening of fruit and inhibits plant growth
cytokinin
following plant hormones prevents plant tissues from senescing, or aging
auxin
plant hormone- Indoleacetic acid (IAA) is the most commonly occurring form
In Plasmodium, sexual reproduction occurs in the
mosquito
In Plasmodium while asexual reproduction occurs in
humans
A common cause of amoebic dysentery is
Entamoeba histolytica.
endosymbiotic theory of organelles
Eukaryotic cells acquired mitochondria and plastids by engulfing free-living bacteria and developed a symbiotic relationship with them. Mitochondria were derived from aerobic bacterium while choloroplasts were derived from cyanobacterium.
organisms belong to the supergroup Excavates
Kinetoplastids, Diplomonads, euglenoids & parabasalids
Members of Supergroup Rhizarian
The organisms pictured are foraminiferans, members of Supergroup Rhizarian and have a skeleton called a test.
These organisms may be used as index fossils to date sedimentary rock.
The Egyptian pyramids are built of this type of limestone.
Trichomonas.
A flagellated protist that is sexually transmitted
Plants give off and take in
plants give off oxygen and water and take in carbon dioxide
What are the 3 horizons (layers) of soil?
A (topsoil): Litter and humus
B (subsoil): Inorganic nutrients
C (parent material): Weathered rock
Soils are a mixture of which three types of particles?
Sand, Silt, Clay
What are three benefits of having living organisms in soil?
Small plants help form soil from rock
Large plants become dominant in certain ecosystems (succession)
Roots penetrate soil to bedrock, opening soil for water, air, and animals.
Soil-dwelling animals mix soil by burrowing.
Earthworms ingest soil particles and deposit them as worm casts.
They also aerate soil.
Soil-dwelling ants construct colonies and loosen and aerate soil.
Microorganisms are responsible for decomposition of humus.
Soil bacteria also make nitrogen available to plants.
What is the Cohesion-tension model
A continuous water column moves passively upward due to transpiration of water through leaf stomata
Waxy cuticle prevents water loss when stomata are closed.
Water enters through root to xylem passively by osmosis and is pulled upward due to tension in xylem.
What is the Pressure-Flow Model of Phloem Transport?
Sieve tubes within phloem form a continuous pathway for organic nutrient transport.
Sucrose is actively transported into phloem at the leaves.
Water follows by osmosis, creating positive pressure.
examples of Stimuli
Stimuli include light, gravity, carbon dioxide levels, pathogen infection, drought, and touch.
Short term stimuli
Stomata open and close in response to light levels.
Long term stimuli
The response to gravity causes downward growth of the root and the upward growth of the stem.
signal transduction
Response of plants to environmental stimuli can be carried out by this which involves receptors, transduction pathway and a cellular response
what environment do protist live in
They live in any environment that contains water
protist means
typically is used in reference to a eukaryote that is not a true animal, plant, or fungus or in reference to a eukaryote that lacks a muticellular stage
prostist share characteristics with which other domain and how?
Eukaryotes that share some Archaea characteristics (e.g. biochemistry & genetics)
Lacks the peptidoglycons in cell walls of bacteria
Otherwise varies in modes of Eukarya reproduction, locomotion, & morphology
Endocytosis; 1o endosymbiosis with prokaryotes
2o endosymbiosis: heterotroph engulfing red or green algae
Evolution and diversity of protists
Complexity and diversity of protists makes them difficult to classify.
Many classification schemes proposed
None has broad support
Cannot be classified as plants, animals, or fungi
Not monophyletic
Do not all belong to the same evolutionary lineage
size of protist
Vary in size from microscopic algae and protozoans to kelp more than 200 m in length
Brown algal protists some forms may reach a length of 60 metres (197 feet) or more.
A common range in body length, however, is 5 μm
Some parasitic forms (e.g., the malarial organisms) and a few free-living algal protists may have a diameter, or length, of only 1 μm
Although many protists are unicellular, they are
highly complex.
Amoeboids and ciliates possess unique organelles, such as contractile vacuoles.
Some protists are colonial or filamentous.
nutrition of protist
Some are photosynthetic Many are heterotrophic Some ingest food by endocytosis Some are parasitic Some are mixotrophic Combine autotrophic and heterotrophic nutritional modes
protist life cycles
Asexual reproduction is common.
Sexual reproduction may occur when conditions are unfavorable.
Formation of spores allows protists to survive hostile environments.
A cyst is a dormant cell with a resistant outer covering which can survive until favorable conditions return.
In parasites, a cyst may serve as a means of transfer to a new host.
why are protist are an enormous ecological importance.
Source of food
Source of commercial products - Marine protists are source of useful substances like algin, agar, carragean and antiseptics
Primary producer of aquatic ecosystem - Many protists are primary producers, they play a basic role in food cahins, providing food and oxygen.
Source of medicines - Sodium laminaria sulphate, Fucoidin, Heparin are algal products used as blood coagulants. Lyngbya produces an anti-cancer compound.
Pathogens - May cause many disease in man and also in fruits and vegetables it causes late blight potatoes and causes disease in some fishes.
Malaria! –Plasmodium species
protist that use Photoautotrophic forms
Produce oxygen
Function as producers in both freshwater and saltwater ecosystems
Major component of plankton
Organisms that are suspended in the water
Serve as food for heterotrophic protists and animals
Whales, the largest animal in the sea, feed on plankton, one of the smallest
protist are classified into six supergroups
Archaeplastida Chromalveolata Excavata Amoebozoa Opisthokonta Rhizaria
Supergroup Archaeplastida
Includes land plants and other photosynthetic organisms that have plastids derived from endosymbiotic cyanobacteria
Green algae refers to many phyla of protists that carry out photosynthesis. (approximately 17,000 species)
Inhabit a variety of environments including oceans, freshwater, snowbanks, tree bark, and turtles’ backs
Many are symbionts with fungi, plants, or animals
Morphology varies
The majority are unicellular, but many are filamentous or colonial.
They may be orange, red, or red-colored.
Subdivided into chlorophytes and charophytes (remember this is for dividing Green algae)
Land plants are thought to be derived from charophytes.
Chlorophytes: Chlamydomonas belong to which supergroup
Archaeplastida
what are chlorophytes: volvox
Volvox (a colonial chlorophyte)
A colony is a loose association of independent cells.
A Volvox colony:
A hollow sphere
Thousands of cells arranged in a single layer surrounding a watery interior
Flagella beat in a coordinated fashion
Some cells are specialized for reproduction
Chlamydomonas
A minute (
Green algae
refers to many phyla of protists that carry out photosynthesis. (approximately 17,000 species)
Inhabit a variety of environments including oceans, freshwater, snowbanks, tree bark, and turtles’ backs
Many are symbionts with fungi, plants, or animals
Morphology varies
The majority are unicellular, but many are filamentous or colonial.
They may be orange, red, or red-colored.
Subdivided into chlorophytes and charophytes (remember this is for dividing Green algae)
Land plants are thought to be derived from charophytes.
Ulva
Ulva (a multicellular chlorophyte) Multicellular green alga Commonly called sea lettuce Body is two cells thick and can be as much as a meter long Sexual cycle involves alternation of generations Similar to higher plants, except Both generations look exactly alike. The gametes all look the same.
red algae
Multicellular seaweeds (About 5,000 species)
Possess red and blue accessory pigments, which transfer energy from absorbed light to the photosynthetic pigment chlorophyll during photosynthesis
Live mostly in warmer seawater, some at depths greater than 70 m
Economic Importance
Agar – capsules for drugs, dental impressions, cosmetics, culture medium, electrophoresis, food prep
Carrageenan – an emulsifying agent used in the production of chocolate and cosmetics
The reddish-black wrappings around sushi rolls consist of processed Porphyra blades.
Supergroup Chromalveolata
Chromalveolata include two large supergroups: stameophiles and alveolates.
Stamenophiles include brown algae, diatoms, golden brown algae, and water molds.
Brown algae
About 1,500 species
Most live in colder ocean waters along rocky coasts
Multicellular
Morphology:
Some are small forms with simple filaments.
Others are large multicellular forms that may exceed 200 m in length.
Accessory pigments provide brown color.
Excess food is stored as a carbohydrate called laminarin.
Supergroup Chromalveolata: Stamenophiles
Multicellular forms of green, red, and brown algae called seaweeds
Laminaria (a kelp) and Fucus (rockweed) are common intertidal seaweeds.
Nereocystis and Macrocystis often form forest-like thickets in deeper waters.
Sargassum forms floating masses where other organisms find shelter.
Harvested for food and fertilizer
Macrocystis is the source of algin, a thickener for foods such as ice cream, sherbet, and cream cheese
Diatoms
are the most numerous unicellular algae in the oceans. Reproduce sexually and asexually Ornate silica shell Remains of diatoms are used as A filtering agent Soundproofing material A polishing abrasive
Golden brown algae
Have yellow-brown carotenoid accessory pigments
Unicellular or colonial
Usually have two flagella with tubular hairs
About 1,000 species
Many, such as Ochromonas, are mixotrophs
Can photosynthesize and phagocytose
Contribute to freshwater and marine phytoplankton
Water molds
(Nearly 700 species described)
Most live in the water; form furry growths when they parasitize fishes or insects and decompose remains
Some live on land and aprasize insects and plants
Most are saprotrophic
