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Live and Living Organisms

Topic ¹1

Science and Scientific Methods

 

Topic ¹3

Instruments Used in the Biology Laboratory

Biology labs contain instruments and tools to help scientists study living creatures--from single-celled amoebas to massive plants and mammals. Specialized scientific equipment enables biologists to study cellular processes, genetics, bacteria and other life forms that are invisible to the naked eye. Scientists need sophisticated instruments to investigate how living organisms function, breathe, eat, reproduce and evolve. Typically, students are first introduced to essential instruments in high school or college biology labs.

Microscopes

A microscope is an essential instrument for biologists because it allows scientists to see things that are invisible to the naked eye. Several fields within biology are based on microscopes, including cellular and molecular biology, microbiology, bacteriology and many others. Microscopes come in a variety of styles and are designed for use in different situations. In school biology labs, the most common type is a single-lens, optical microscope, which uses light to magnify biological or cellular material that is stained or prepared on a slide. Compound microscopes use multiple lenses that offer improved magnification and contrast to better study cells, tissues or other materials. Other types of microscopes used in biological studies include powerful electron transmission scopes, phase contrast scopes and florescence scopes.

Glasswares

Laboratory flasks are vessels (containers) which fall into the category of laboratory equipment known as glassware. In laboratory and other scientific settings, they are usually referred to simply as flasks. Flasks come in a number of shapes and a wide range of sizes, but a common distinguishing aspect in their shapes is a wider vessel "body" and one (or sometimes more) narrower tubular sections at the top called necks which have an opening at the top. Laboratory flask sizes are specified by the volume they can hold, typically in metric units such as milliliters (ml) or liters (L or l). Laboratory flasks have traditionally been made of glass, but can also be made of plastic.

 

At the opening(s) at top of the neck of some glass flasks such as round-bottom flasks, retorts, or sometimes volumetric flasks, there are outer (or female) tapered (conical) ground glass joints. Some flasks, especially volumetric flasks, come with a stopper or cap for capping the opening at the top of the neck. Such stoppers can be made of glass or plastic. Glass stoppers typically have a matching tapered inner (or male) ground glass joint surface, but often only of stopper quality. Flasks which do not come with such stoppers or caps included may be capped with a rubber bung or cork stopper.

 

Flasks can be used for making solutions or for holding, containing, collecting, or sometimes volumetrically measuring chemicals, samples, solutions, etc. for chemical reactions or other processes such as mixing, heating, cooling, dissolving, precipitation, boiling (as in distillation), or analysis



Named Glasswares

Suction flask - flask designed for filtration. The thick-walled, conical-shaped, the upper part has a tube for connection to a vacuum pump or a vacuum line. Adapted for operation under reduced pressure.

Erlenmeyer flask - conical flask, which is used in the analytical work, in particular in the titration.

The flask Wurtz - round bottom flask with a glass soldered to the throat outlet tube. Used as part of the distillation apparatus.

Claisen flask - is used for distillation under ordinary pressure or vacuum distillation. Is a round-bottom flask, which departs from the throat second neck having an outlet tube.

Flask Tabor - intended for distillation under ordinary pressure or vacuum distillation. Is a two-necked flask, upper neck which has a branch pipe.

Kjeldahl flask - is intended for the determination of nitrogen in substances by the Kjeldahl method.

Flask Bogdanov’s - intended for the distillation of paraffin (including vacuum) and determining the boiling range.

 

 

Tasks

Answer the questions

1) What instrument allows scientists to see things that are invisible to the naked eye?

2) What types of microscope do you know?

3) What instrument can be used for making solutions or for holding, containing, collecting?

 

Topic ¹5

Live and Living Organisms

In biology, an organism is any contiguous living system, such as a vertebrate, insect, plant or bacterium. All known types of organism are capable of some degree of response to stimuli, reproduction, growth and development and self-regulation (homeostasis).

An organism may be either unicellular (a single cell) or, as in the case of humans, comprise many trillions of cells grouped into specialized tissues and organs. The term multicellular (many cells) describes any organism made up of more than one cell.

An organism may be either a prokaryote or a eukaryote. Prokaryotes are represented by two separate domains, the Bacteria and Archaea. Eukaryotic organisms are characterized by the presence of a membrane-bound cell nucleus and contain additional membrane-bound compartments called organelles(such as mitochondria in animals and plants and plastids in plants and algae, all generally considered to be derived from endosymbiotic bacteria). Fungi, animals and plants are examples of kingdoms of organisms within the eukaryotes.

Living organisms have the unity structural structure, metabolism, life support systems and adaptation to the environment.

According to the law of physical and chemical unity of a living organism (the aggregate of organisms on the planet), the open VI Vernadsky as a result of the spectral analysis of the substance of many organisms, the living substance of the Earth consists of a fairly small group of chemical elements. Elements necessary living in a larger amount than the other, called macrocells (C, H, O, N, S, P, K, Na, Mg, Ca, Cl). They are usually in the form of ions is performed similar role in the regulation of various life forms.

In most species found living simple organic compounds such as amino acids, monosacharides, peptides and fatty acids, which are constructed larger polymers: proteins, carbohydrates, lipids and nucleic acids, respectively.

The basic mechanism of metabolism in various forms of life is enzymatic reactions are divided on the synthesis reaction and decay, the totality of which is called a cell or organism metabolism.

All processes are controlled by the power enzymatic reactions. By type of food organisms are divided into autotrophic, producing organic compounds from simple inorganic compounds when exposed to sun or chemical energy (plants and some bacteria) and heterotrophic, used to power the finished organics (mostly animals, as well as a number of micro-organisms and fungi).

Breathing can be called the processes of obtaining chemical energy by oxidation of organic substances. These include not only the external respiration, which requires specialized organs (lungs, gills), but also the breath that occurs in the cells of the body.

Breathing can be called the processes of obtaining chemical energy by oxidation of organic substances. These include not only the external respiration, which requires specialized organs (lungs, gills), but also the breath that occurs in the cells of the body-types of immune-t. e. the ability to recognize a living organism invasion agents carrying heterologous genetic information and cell mobilizing agent formed of a more rapid and effective removal of foreign matter.

A characteristic feature of all living things is irritability or sensitivity. All organisms need a certain degree of internal coordination and regulation; proper relationship between stimulus and response is necessary to maintain the viability and survival of the organism.

One of the most important of behavioral live is mobility - properties of the organism, which allows to avoid danger and to find food sources, as well as the most sensitive and fast response to their pollution.

For life - growth, reproduction and functioning of living beings need an environment well-defined chemical composition

Tasks

Put the words instead of dots

1) A characteristic feature of all living things………

2) One of the most important of behavioral live is ………

3) The basic mechanism of metabolism in various forms of life is ……

Topic ¹ 7


Date: 2015-12-11; view: 746


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