Abscisic acid is one of the phytohormones present in plants and was firstly discovered in 1963 by Frederick Addicott and his colleagues (Fursule, Kulkarni, & Agarkar, 2006). It plays an important role in regulating the physiological process especially in extreme conditions, besides plant growth and plant development. Under non-stressful conditions, abscisic acid presents in low levels in plants cells. This is because plant cells require just a low level of abscisic acid for normal growth. In stress conditions like extreme environments, abscisic acid content increases when plants exposed to extreme environments such as water shortage, salt stress, and cold. When there is water deficiency in plants, the concentration of abscisic acid in plants’ cells increases triggering the closure of stomata. Karp (2009) stated that “abscisic acid binds to a GPCR in plasma membrane of guard cells” (p.638). The receptors then activate several pathways in response to this condition. This attachment causes the opening of Ca2+ channels which transfer Ca2+ from vacuole into cytosol. At ...
O’Leary, J., and Knecht, G. 1986. Elevated CO2 concentration increases stomate numbers in Phaseolus vulgaris leaves. Botanical Gazette. 142: 438-441.
Most substances fall on a scale ranging from the most acidic to the the most basic with neutral substances falling somewhere in the middle. Scientists call this the pH scale. pH levels are measured in numbers,0 to 14. The closer a substance is to zero the more acidic it would be. The closer to 14 the more basic a substance would be.Now what defines an acid and a base, one might ask? There are three ways of defining acids, each singling out a specific property. The first theory is the Arrhenius Theory with states, that an acid is a substance that produces the ion H+ when in a water solution, while a base is a substance which produces the ion OH- when in a water solution. Examples of an Arrhenius acid are HCl and HNO3. Examples of an Arrhenius base are NaOH and AlOH3.
Hydrochloric acid is a strong and corrosive acid that is often used as a reagent in laboratories.
The basis for the symbiotic relationship in these species is complex. The infection of the host cell by rhizobia occurs within the plant’s root nodules. Bacteroides, gram-negative anaerobic bacteria, are isolated from the host cell by a peribacteroid membrane; the membrane between the plasma membrane of the cell and the membrane of the bacteroid. The bacteroid contains differentiated rhizobia, which are able to fix nitrogen due to the supply of carbon from the host plant. Sucrose is delivered to the nodules of the root via the phloem, where it is cleaved by suc synthase, and enters the Krebs cycle. The product of glyco...
As a result of these factors, the flora has adapted to these conditions in a variety of ways including their shape, leaf type, root system, and color. One of the most prominent adapt...
In this laboratory experiment, the rate of photosynthesis was measured through the use of the “floating leaf disk technique.” The leaf disks were placed into a syringe and the O2 and CO2 in the mesophyll layers of the leaves were removed and then replaced with sodium bicarbonate or water, causing the leaves to sink to the bottom of the container. If one determines the number of leaf disks rising to the top as a result of an increase in oxygen gas in the mesophyll cells, then the rate of photosynthesis is able to be measured because O2 is a product of photosynthesis. The first step of this experiment was a feasibility study of the variance in the photosynthetic activity of the leaf disks in both water and bicarbonate solutions. After five minutes of light exposure, all of the leaf disks in the bicarbonate solution (10 disks) had ...
The late sixties were a time filled with sex, drugs, and rock and roll. A huge part of American culture at the time was focused around these three things. Musicians possessed a tremendous amount of social influence, and like wise, society put a lot of emphasis on the lives and attitudes of musicians. Of the rock groups from this time period, the Beatles were by far the most influential. The British rock group was probably the most catalytic band in rock and roll history. Although they came together in the shadow of the Beatles, another band of that era was Jefferson Airplane. Jefferson Airplane was deemed the first of the San Francisco psychedelic rock groups. Jefferson Airplane was always considered to be a psychedelic rock group, but it was not until later in their existence that the Beatles fell into this category as well. Both groups earned this title for their creative style of rock as well as for their experimentation with drugs. Each of these groups wrote songs that alluded to drug use at one time or another. Two of the most criticized songs from these bands are Lucy in the Sky with Diamonds by the Beatles, and White Rabbit by Jefferson Airplane. White Rabbit is a song latent with drug references. The connection with drugs in Lucy in the Sky with Diamonds is not as clear. Although John Lennon claims that he had no intention of making references to LSD in his song, the abstract lyrics and metaphoric language invite drug connotation. Lucy in the Sky with Diamonds and White Rabbit mirror each other in their association with LSD and their allusions to Alice in Wonderland, but looking into these songs more deeply it is obvious that both artists were writing about escape; escaping reality.
If a plant cell is places in a hypotonic solution the cell has a lower water concentration to that of the solution. Water will move into the cell by osmosis from a high water concentration outside the cell to a lower water concentration inside the cell through a selectively permeable membrane. The cell becomes turbid
Plant hormones are certain chemicals present in plants that control plant growth and development by affecting the division, differentiation, and elongation of cells. (Campbell, 2008) Each hormone has multiple effects depending on its site of action, its concentrations, and the developing stage of the plant. (Campbell, 2008) Auxin is a plant hormone that is synthesized within the apical meristems and young leaves of a growing plant. Auxin stimulates stem elongation when it is present is low concentrations. It promotes the formations of lateral and adventitious roots, regulates development of fruit, enhances apical dominance, functions in gravitropism and phototropism, promotes vascular differentiation, and retards leaf abscission. Gibberellic acid is one of several plant hormones that govern a plant’s growth. Gibberellins allow for stem elongation in plants. Plants without enough of this hormone tend to grow short or stunted. This chemical is high in the element potassium, which is one the main components of plant fertilizer and very important for plant growth on its own. The...
- The amount of times the mixture was stirred. We stirred the mixture until the Ammonium Nitrate was dissolved, so the amount of times we stirred after each teaspoon was different.
Plant defences are those mechanisms employed by plants in response to herbivory and parasitism. According to Hanley et al. (2007), “the tissues of virtually all terrestrial, freshwater, and marine plants have qualities that to some degree reduce herbivory, including low nitrogen concentration, low moisture content, toxins or digestibility-reducing compounds”. The type of chemical defence may be species specific (Scott 2008). The defences that plants possess may be in the form of chemical production or in the form of physical defences such as thorns or spikes and even through reinforced, rigid leaves. “The compounds that are produced in response to herbivory can either have a direct effect on the attacker itself (e.g. toxins or digestibility reducers), or serve as indirect defenses by attracting the natural enemies of the herbivores” (Bezemer & van Dam 2005). This essay will focus on chemical plant defences and in particular the effects of terpenes, phenolics, nitrogen-based defences as well as allelopathy in plants.
BIOC 2200 – Experiment 1: Buffers and the effect on amino acids. Aiden Forsyth 1009696399 Wednesday PM Bench 13 Results Question A1 - What is a.. By the Henderson-Hasselbalch equation (Plumber, 2004). pH=pka+log([HA])/([A-]) n_([HA])=M*V=0.10 mol/L*0.050L=0.0050 mol n_[A-] =
Water passes into cells through a special type of diffusion called osmosis. Water molecules diffuse through the membrane from a weak solution into a strong solution until the concentration is the same on both sides. A membrane that allows only certain molecules to pass through is called a semi-permeable membrane. In a plant, water passes from a weak cell sap solution to an adjoining cell with a stronger solution, as water passes in, the volume of the sap vacuole increases. When a full sap vacuole presses against the cell wall, it is said to be turgid. If water that is lost is not replaced the sap vacuole shrinks and pulls on the cell wall, the cell becomes flaccid; this is known as plasmolysis.
The strong cells wall prevents bursting. The cell is turgid. If plant cells lose water the cells become limp and flaccid. Water is essential for support in plants.
Acids are substances that, when added to water produce hydrogen ions. Hydrogen Ions are the combination of hydrogen and water molecules. There are many types of acids, which consist of citric, hydrochloric, carbonic, sulfuric, acetic, nitric, phosphoric, and lactic acids. Acids react with zinc, magnesium, and aluminum forming hydrogen. They turn blue litmus paper red. Litmus is used to check for acidity. Acids are sour, react with metals to produce hydrogen gas, and react with carbonates to produce carbon dioxide gas. Strong acids dissociate in water forming hydrogen ions and an anion. Weak acids partially dissociate in water, to form hydrogen ions and an anion, an anion is a negatively charged particle.