Moulds, those dusty little spots often found spreading over bread, cheese, books, and other things in the home, cause the loss of millions of dollars to our economy every year and, even worse, may be a menace to your health. To deal with them successfully we must understand what moulds are and exactly what they are doing.
Moulds are microscopic, plant-like organisms, composed of long filaments called hyphae. Mould hyphae grow over the surface and inside nearly all substances of plant or animal origin. Because of their filamentous construction and consistent lack of chlorophyll they are considered by most biologists to be separate from the plant kingdom and members of the kingdom of fungi. They are related to the familiar mushrooms and toadstools,differing only in not having their filaments united into large fruiting structures. For our purposes here, we shall consider as moulds only fungi that are commonly encountered n the home and laboratory and that can be easily grown and studied.
When mould hyphae are numerous enough to be seen by the naked eye they form a cottony mass called a mycelium. It is the hyphae and resulting mycelia that invade things in our homes and cause them to decay.
Reproduction in fungi is complex and involves a great diversity of structures. At the most fundamental level we can say that most moulds reproduce by spores. Spores are like seeds; they germinate to produce a new mould colony when they land in a suitable place. Unlike seeds, they are very simple in structure and never contain an embryo or any sort of preformed offspring. Spores are produced in a variety of ways and occur in a bewildering array of shapes and sizes. In spite of this diversity, spores are quite constant in shape, size, colour and form for any given mould, and are thus very useful for mould identification.
The most basic difference between spores lies in their method of initiation, which can be either sexual or asexual. Sexually initiated spores result from a mating between two different organisms or hyphae, whereas asexual spores result from a simple internal division or external modification of an individual hypha. the recognition of a mating and subsequent spore formation is often difficult for an observer,and is usually reserved for patient specialists. However, for practical purposes one can learn to recognize certain indications of the sexual process, namely, the four kinds of sexually determined spores that appear in mould fungi: (1) oospores, (2) zygospores, (3) ascospores, and (4) basidiospores.
Jellyfish, corals, and hydras belong to the group of animals called cnidarians.
The main characteristic of this group is that all of its members possess specialized cells called cnidocytes which often produce venom and have a role in capturing the animals prey.
Answer:
1.
Explanation:
A signal from one gland to another would not be intercellular, as "inter" means inside. This means intercellular would stand for "Inside the Cell"
Answer No 1:
Phospholipids are made up of phosphorus head and two fatty acid molecules. These phosphorus head and fatty acid tail is joined together by glycerol. Fatty acid molecules are made up of Carbon, hydrogen and oxyge. Hence,carbon and hydrogen can be said as two other elements present in phospholipids.
Answer No 2:
The building blocks of lipids are glycerol and fatty acids.
Lipids can be described as vital organic molecules which are not soluble in water. They are made up of chains of carbon, hydrogen and oxygen. Someof the examples of lipids are fats and oils. Lipids are the main molecules present in an organisms cell membrane and hence have huge biological importance.
Answer No 3:
Lipids are biologically important molecules as they play very vital roles in the functioning of an organisms body. Two of the functions of lipids are:
- Lipids and phosphorus molecules combine to form phospholipids. The phospholipids are the main molecules out of which the cell membrane is made. Hence, lipids play an essential role in providing the cell membrane its structure.
- Lipids store energy and provide insulation to the body of an organism.
