The Endocrine System
Anatomy & Physiology The Endocrine System Task 1 . List the major endocrine glands of the body. Describe their structure and location. Adrenal Gland (Medulla and Cortex). Thyroid Gland. Para-Thyroid Gland. Pituitary (3 Lobes - Anterior, Median and Posterior). Testes and Ovaries. Placenta. Pineal Gland. Pancreas1. Name of Gland Structure Location Adrenal Gland The adrenal gland has three main sections. At the surface of the gland is a thick capsule, which binds the gland to the kidney surface and protects its glandular tissue below. The adrenal glands are paired glands, with each one sitting atop each kidney and are embedded in the fat enclosing the kidney. The next layer is the cortex which has three identifiable layers, the zona glomerulosa, the zona fasciculate and the zona reticularis. The inner most layer is the medulla which has a rich blood supply and is composed of nerve cells. Thyroid Gland The thyroid gland consists of two lateral lobes, called the left and right lateral lobes. A bridge of tissue connects the two lobes, called the isthmus. Internally, the thyroid gland is made-up of hollow, spherical follicles. The thyroid gland is shaped similar to shield. It is found in the neck, in front of the trachea and below the larynx. Name of Gland Structure Location Parathyroid Gland The four parathyroid glands are each about the sixe
Photosynthesis - Absorption spectrum.
Photosynthesis light Water + carbon dioxide › glucose + oxygen 6H2O + 6CO2 › C6H12O6 + 6O2 Absorption Spectrum An absorption spectrum shows which wavelength of light a molecule absorbs. Action Spectrum An action spectrum shows the effect of each wavelength of light on the rate of photosynthesis The absorption spectrum of chlorophyll is very similar to the action spectrum of photosynthesis. This is evidence that chlorophyll absorbs light for photosynthesis. The Light and Dark Reaction ) The light reaction light 6H2O›12H + 3O2 Light splits water into hydrogen ions and oxygen. 2) The dark reaction enzymes 2H + 6CO2 › C6H12O6 + 3O2 Glucose is then formed from the hydrogen ions and carbon dioxide. (This reaction does not occur in the dark). Factors affecting the rate of photosynthesis The Light Reaction Chlorophyll can split more water molecules at higher light intensities. Photosynthesis will reach a maximum rate when chlorophyll is saturated by sunlight. The Dark Reaction An increase in temperature will increase the rate of glucose production until it reaches the optimum temperature for the enzymes. The enzymes will be denatured if it goes above a certain temperature. An increase in carbon dioxide will also increase the rate of glucose production. Millions of years ago there was much more carbon dioxide in the atmosphere, the plants sucked up the
Investigating Water Potential Of Potatoes.
Investigating Water Potential Of Potatoes. AIM To investigate the effect of various sugar solutions (which have different concentrations of sugar solutions. on a potato. We will be investigating the length of the potato after a certain amount of time. Thus, enabling us to investigate the water potential of a potato. INTRODUCTION The fact that organisms rely on diffusion for the fulfilment of many of their needs has had a profound effect on their structure. Consider, for example, the way gas exchange relates to the size of an organism. The organism's oxygen requirements (its needs) are proportional to its volume, i.e. the bulk of respiring tissue, which it contains. Its exchanges however, are proportional to the surface area over which diffusion of oxygen can take place. In an organism, the effective surface area must be sufficient to fulfil the needs of the respiring tissue (pg. 48 Biology a Functional Approach MBV Roberts). This simple fact also occurs in Osmosis (movement of water molecules from a region of higher water potential to a region of lower water potential through a partially permeable membrane). Although the plasma membrane of a cell is fully permeable to respiratory gases, it is by no means permeable to all substances. The porous nature of the membrane means that only those molecules that are small enough will diffuse through it swiftly. The plasma
The Effect Of Temperature On The Permeability Of The Cell Membrane
"The Effect Of Temperature On The Permeability Of The Cell Membrane" Aim: My aim of this experiment is to investigate whether changing the temperature (independent variable) of the water around a disk of a beetroot will affect the permeability of a beetroot, by measuring the release of pigment (dependant variable) into water using a digital colorimeter. The colorimeter will be used to measure the light absorbency of anthocyanin (the pigment found in the cell membrane of the beetroot) this can help us work out how much diffusion takes place at different temperatures such as 0,20,40, 60 and 80 degrees Celsius. Introduction I will be conducting an experiment to find out what effect different temperatures has on the permeability of the Beetroot's cell membrane; the temperatures that I will be testing on the beetroot is 0, 20, 40 and 60 degrees Celsius. Background Knowledge Most people think that Beetroot cells are colored red because they contain a red dye called anthocyanin, But in fact they are colored red caused by two distinct pigments, there is a yellow one known as a betaxanthin and a purple pigment known as betacyanin and are together they are referred to as betalins. In beetroot cells the red anthocyanin pigment occurs in the vacuoles. A membrane called the tonoplast surrounds each vacuole. The cytoplasm and vacuole is surrounded by the plasma membrane. The
Blood System Assignemnt
A. Discuss the structure of Arteries, veins and capillaries and relate their structure to function. In its journey from the heart to the tissues, the blood passes through channels of six principal types: elastic arteries, muscular arteries, arterioles, capillaries, venules and veins. Each has a critical roll in the function of the circulatory system as shown in Table 1: Structure and Functions of Blood Vessels and also in Table 2: Comparison between Arteries and Veins. In this system, the arteries show a progressive diminution in diameter as they recede from the heart, from about 25 mm in the aorta to 0.3 mm in some arterioles. The reverse is true for the veins; the diameter is small in the venules and progressively increases as the veins approach the heart. (www.ivy-rose.co.uk) All arteries are comprised of three distinct layers, intima, media and adventitia, but the proportion and structure of each varies with the size and function of the particular artery. Arteries are thick-walled muscular tubes which carry blood away from the heart. Blood in the arteries is under high pressure (which is why the walls need to be strong). The artery leading from the heart to the lung, the pulmonary artery, is the only artery that carries de-oxygenated blood. The artery leading from the heart to the rest of the body is called the aorta. (www.ivy-rose.co.uk) A large artery, like the
Investigate the water potential of celeriac.
Aim Investigate the water potential of celeriac. Apparatus Celeriac - this is the specimen that we will be finding the water potential of. .00 mol dm-3 sucrose solution - this will be placed in the test tube in which the experiment will take place. We will dilute the solution to produce a range of concentrations. 0.0ml Graduated Pipettes (x2) - I had a choice of 5.0ml, 10.0ml and 20.0ml graduated pipettes. I chose this size pipette because it is time efficient and accurate at the same time. It is an accurate piece of equipment because as opposed to standard pipettes, this graduated pipette has 0.1ml graduations to ensure the utmost accuracy. One pipette will be used for water and one will be used for sucrose solution. 250ml Beakers (x2) - these will be used to hold water and the 1.00 mol dm-3 sucrose solution in a safe environment. Cork Borer - this will be used to cut the precise shape of the celeriac. This will also ensure that the surface area to volume ratio is constant throughout the experiment. Razor - this will be used to cut the pieces of celeriac to a precise length. Ruler - this will be used to measure the length of celeriac that will be used in the experiment. Scales - they will be used to measure the mass of celeriac before and after the experiment with accuracy. Therefore, the mass increase/decrease can be calculated after the experiment. These scales
Investigating osmosis on swede cells.
Investigating osmosis on swede cells. Aim: To investigate the effect of sucrose solution on swede cells in order to determine the water potential of them. Background information: 'Osmosis is the diffusion of water only. It is the net movement of solvent (water) molecules from a region of high concentration to a region of their lower concentration, through a partially permeable membrane.' 1 Robert. M, Reiss. M, Monger. G, Biology Principles, Nelson, 1993 A diagram summarising the conditions on the two sides of a partially permeable membrane, and the terms used to describe them. The large black blobs represent sucrose molecules, the smaller white circles represent water molecules. The terms 'high' and 'low' relate. In the diagram above the solute molecules are too large to diffuse through the partially permeable membrane but as water molecules are a lot smaller they can diffuse down the concentration gradient to where there is a lower concentration of water molecules. Although there are water molecules on the right side the solute molecules, because they carry a charge become surrounded by a shell of water molecules, and so become hydrated and the result is that the water molecule is no longer free to move around. Therefore osmosis can also be described as 'the movement of water molecules down a concentration gradient of water, from a region of high kinetic energy to a
Effect of Caffeine on the Heart Rate of Daphnia
Objective of Experiment: In 1819, caffeine (IUPAC nomenclature: 1,3,7-trimethyl- 1H-purine- 2,6(3H,7H)-dione) was discovered by a German chemist, Friedrich Ferdinand Runge. It is a bitter white crystalline xanthine that acts as a psychoactive stimulant drug and a mild diuretic in humans and other animals. Caffeine, an odourless and slightly bitter alkaloid, is found in coffee, tea ,kola nuts, ilex plants (the source of the Latin American drink maté ), and, in small amounts, in cocoa, where it acts as a natural pesticide that paralyzes and kills certain insects feeding on the plants. It is also known as guaranine when found in guarana, mateine when found in mate, and theine when found in tea; all of these names are synonyms for the same chemical compound. It is most commonly consumed by humans in infusions extracted from the cherries of the coffee plant and the leaves of the tea bush, as well as from various foods and drinks containing products derived from the kola nut. Other sources include yerba mate, guarana berries, and the Yaupon Holly. Caffeine is absorbed rapidly into the bloodstream from the gastro-intestinal tract in human whenever consumed. It reaches maximum concentration in circulatory system within about an hour. The blood distributes it throughout the body. It even manages to pass through the blood-brain barrier. Early experiments showed that low
Biology: Field Project
Biology Coursework An investigation to discover the relationship between the percentage cover of Birch seedlings and the increased light intensity Research and Rationale My investigation involves the plant species, Silver Birch, the generic name for this plant is Betulaceae, the purpose of this investigation is to discover the affect light intensity has upon it. Silver Birch is a deciduous tree, this type of tree naturally loses its leaves in autumn when the temperature climates. The reason for this is to overcome a water shortage which occurs due to low soil temperatures, this inhibits sufficient active uptake of water by the root system to counteract the water loss if the trees had retained their leaves¹. It is necessary to acknowledge that when I am recording the light intensity it could mean that there is a direct link between itself and the temperature, it is likely that an increase in light intensity will follow with an increase in temperature and vice versa. There will also be a number of uncontrollable variables which I will have to record, they are the following; Wind speed, temperature, soil temperature, soil pH, soil moisture and humidity. When I will be looking at the percentage cover of Betulaceae it will very similar to looking at the growth of the Betulaceae. It is important to look at different perceptions of biology principles in order to link them
Determining the Water Potential of Sweet Potato Tissue
Determining the Water Potential of Sweet Potato Tissue Introduction The aim of this experiment is to determine the water potential of sweet potato tissue using osmosis. This can be achieved by placing the samples inside different molarities of sucrose solution and work out the percentage change in mass and then with the aid of a conversion graph convert molarity to water potential (kPa), without the weight of the sweet potatoes being a factor. Background Knowledge In mature plant cells, the fluid filled vacuole occupies most of the cell volume therefore in order to determine the water potential of the sample I would need to work out the water potential of this fluid inside the cell. Substances can pass in and out of cells by four different processes: * Diffusion * Osmosis * Active transport * Endocytosis & exocytosis All these processes involve substances passing through the cell membrane of the cell. In this investigation, I only need to consider osmosis. OSMOSIS is the movement of water molecules from a region of higher water potential to a region of lower water potential through a partially permeable membrane. This is a colligative property i.e. dependent on the concentration of particles in a solution. The water molecules involved always move down a ? gradient. It happens because of the natural kinetic energy possessed by the particles, which makes them move
