FUNGI DEFINITION | Fungi are organisms that lack chlorophyll.

FUNGI DEFINITION

Definition of Fungi are organisms that lack chlorophyll, the green coloring matter that many plants use to make food. Fungi cannot make their own food. Instead, they absorb food from their surroundings. There are over 70,000 species of fungi. Yeasts and other one-celled fungi are too small to be seen without a microscope. But most types can be seen with the unaided eye. Some of the most common fungi include mildews, molds, mushrooms, and plant rusts.

 Fungi Pictures

Fungi structure : Parts of a fungus. 

Fungi structure Except for yeasts and other one-celled fungi, the main part of a fungus consists of thousands of threadlike cells called hyphae. These tiny, branching cells form a tangled mass called a mycelium. In many kinds of fungi, the mycelium grows beneath the surface of the material on which the organism is feeding. For example, the mycelium of a mushroom often grows just beneath the surface of the soil. The umbrella-shaped growth known as a mushroom is actually the fruiting body of the fungus. The fruiting body produces cells called spores, which develop into new hyphae. Spores are smaller and simpler than the seeds of plants, but both enable an organism to reproduce.

Some bread molds and microscopic species of fungi bear spores in tiny structures called sporangia. In black bread mold, the sporangia form at the tips of upright hyphae called sporangiophores. Other hyphae called stolons spread over the surface of the bread. They are anchored by rhizoids (rootlike structures). Groups of sporangia usually form above the rhizoids.

Fungi Pictures

Fungi characteristics How a fungus lives. 

Fungi characteristics  Fungi live almost everywhere on land and in water. Some fungi are parasites that feed on living plants and animals. Other fungi, called saprophytes, live on decaying matter. Still other fungi live together with other organisms in ways that are mutually beneficial. Such a relationship is called symbiotic. For example, a fungus and an organism called an alga may live together symbiotically to form a lichen. Some fungi also live with the roots of plants in a symbiotic relationship known as a mycorrhiza. The fungus takes carbohydrates from the plant. In return, the fungus helps supply the plant with water and such important minerals as phosphorus, potassium, iron, copper, and zinc. Most species of trees, shrubs, and herbs have mycorrhizal relationships with fungi.



Mycorrhiza is the symbiotic association of the mycelium of certain fungi with the roots of certain higher plants,living in close relationship with the surface cells. Ex. It is possible with many, if not all, species of plant which normally form mycorrhizas in natural conditions to grow them in artificial surroundings without their appropriate fungi.

Fungi cannot produce their own food because they do not contain chlorophyll. They take carbohydrates, proteins, and other nutrients from the animals, plants, or decaying matter on which they live. Fungi discharge chemicals called enzymes into the material on which they feed. The enzymes break down complex carbohydrates and proteins into simple compounds that the hyphae can absorb.

Fungi Pictures

Types of Fungi.

Most kinds of fungi reproduce by forming spores. Some spores are produced by the union of gametes (sex cells). Others, called asexual or imperfect spores, are produced without the union of gametes. Many fungi produce spores both sexually and asexually. Many spores are scattered by the wind, and others are transported by water or by animals. Mushrooms and some other fungi forcefully discharge their spores. A spore that lands in a favorable location germinates (starts to grow) and eventually produces a new mycelium.

Types of Fungi. Yeasts can reproduce by forming spores, but many kinds of yeasts reproduce by budding. When a yeast buds, a bulge forms on the cell. A cell wall grows and separates the bud from the original yeast cell. The bud then develops into a new cell. Budding produces a large number of yeast cells rapidly.