Plants and Fungi

What are some characteristics of fungi?

Fungi have a cellular structure, the presence of Hyphae, Septate Hyphae and Aseptate Hyphae.

Runners:

Runners are stems that run close to the soil. They may develop some roots at nodes, where a bud can develop into a new plant. Strawberry plants have runners.

Sac Fungi

Sac fungi belong to phylum Ascomycota. Sac fungi, also known as ascomycetes, have a saclike structure that contains ascospores, spores that are nonmotile. Sac fungi generally reproduce asexually, as seen in unicellular forms such as yeast. But multicellular forms may reproduce sexually. Sac fungi can live in a varied range of habitats, and they exhibit all three forms of nutrition—saprophytic, parasitic, and mutualistic.

Saprophytic fungi:

Saprophytic fungi feed on dead or decaying plants and animals. They help in the biodegradation of organic waste matter, such as rotting leaf debris or animal carcasses.

What are the three categories fungi nutrition fall into?

Saprophytic fungi, Parasitic fungi and Mutualistic fungi.

Plant Classification

Scientists have classified plants based on the presence of vascular tissue.

Reproduction of Fungi

Some fungi undergo only asexual reproduction, while others demonstrate both asexual and sexual reproduction.

Bracts:

Some plants such as poinsettias have modified leaves called bracts. These leaves change color during periods of darkness. The brightly colored bracts also attract pollinators toward the small flowers that grow near the center of the bract cluster.

Nastic Response:

Some responses are independent of the direction of the stimulus. These responses are called nastic responses. A simple nastic response is leaves opening during the day and closing at night. This response helps the plant conserve heat.

Types of fungi

chytrids, common molds, sac fungi, and club fungi.

What are two types of root systems?

taproot and fibrous root.

Angiosperms:

Angiosperms form the largest division of plants and have a wide range of habitat. They bear flowers. In angiosperms, the ovary completely encases the seed. As the ovary matures into a fruit, it protects the seed and helps to disperse it. Next, we'll look at the reproductive parts of a flower.

Parasitic fungi:

Parasitic fungi feed on living plants and animals. In the process, they inflict diseases on the plants and animals.

Phototropism:

Phototropism is a positive tropism in which plants tend to grow toward a light source. For example, the stems of plants placed by a window will curve in the direction from which light enters.

Cylindrical leaves:

Pitcher plants have funnel-shaped cylindrical leaves. These leaves help the plants trap insects, which they later ingest. Although pitcher plants perform photosynthesis, they obtain their nitrogen requirement from insects.

Structures of Plants

Plants are made up of various structures such as roots, stems, and leaves.

Spines:

Plants, such as cacti, that grow in dry, arid regions have modified leaves called spines. Spines reduce water loss through transpiration. Additionally, the sharp spines prevent animals from eating the plants.

Pteridophytes (seedless vascular plants)

Pteridophytes are a group of seedless plants that include ferns and horsetails. These plants grow in moist, tropical regions. But during water scarcity, they can enter a dormant stage. In dry weather, ferns are capable of producing spores without fertilization. Ferns also exhibit alternation of generations. This process involves a sporophyte, which is the mature plant that releases haploid spores stored underneath fern leaves. The spores then germinate to form a free-living gametophyte. This gametophyte consists of both male and female gametes that fertilize to form a sporophyte.

Roots

Roots help to firmly anchor a plant underground. Roots also help to absorb water and nutrients from the soil. A root cap covers the tip of the root. Cells in the root tip actively divide, causing the root tip to lengthen and extend into the soil. In addition, the root cap produces a lubricant that protects the root from friction.

Bulb:

A bulb is a small, fleshy stem surrounded by leaves that stores food. Onion stems and tulip stems are bulbs.

Fibrous root:

A fibrous root consists of a bunch of thin, small roots. Monocotyledonous (monocot) plants that have only one cotyledon, such as wheat, bamboo, grass, and bananas, have fibrous roots.

Rhizome:

A rhizome grows underground in a horizontal manner. It's capable of asexual reproduction and may store food. Some ferns and irises have rhizomes.

Taproot:

A taproot consists of a thick main root with branches emerging from it. Most dicotyledonous (dicot) plants, such as carrots and sugar beets, demonstrate a taproot system. A cotyledon is a part of seed that becomes the first set of leaves to appear from the seed. Dicotyledonous plants have two cotyledons.

Tuber:

A tuber is a fleshy stem that can grow below the ground and store food. It might develop buds, which produce new plants. Potatoes, for example, aren't roots—they're tubers.

Chytrids

Chytrids belong to phylum Chytridiomycota. Scientists believe that chytrids were the first type of fungi to appear, because they're closely related to protists. Chytrids have a pot-shaped structure. They can reproduce asexually and sexually, but they generally undergo asexual reproduction that involves flagellated spores called zoospores. Some chytrids are saprophytic, while others are parasitic. They thrive in aquatic habitats and humid areas, such as rain forests, swamps, and bogs.

Club Fungi

Club fungi, also called basidiomycete, belong to phylum Basidiomycota. They have erect, simple, or branched fruiting bodies that contain spores. Club fungi generally reproduce sexually. They are multicellular and mostly have terrestrial habitats. They exhibit all three forms of nutrition—saprophytic, parasitic, and mutualistic.

Common Molds

Common molds belong to the phylum Zygomycota. Common molds, also called zygomycetes, are terrestrial in habitat and exhibit all three forms of nutrition—saprophytic, parasitic, and mutualistic. They produce two types of specialized hyphae, stolons and rhizoids. Stolons spread over the food surface, while rhizoids penetrate the food to absorb nutrients. Common molds generally reproduce asexually. They reproduce sexually only if conditions are unfavorable for asexual reproduction. They don't have defined genders. Instead, they exhibit positive and negative mating strands. The two mating strands produce spores that fuse to form a zygote called a zygospore. The zygospore remains dormant until environmental conditions turn favorable for growth.

Increased Food Demand, Space:

Crop production requires land. But with the ever-increasing population, land availability is limited.

Growing seasons and climate demands:

Each crop grows only at certain times of the year and in a certain climate. So, all crops can't be grown throughout the year and in all regions in equal quantities.

Cellular Structure of fungi

Fungi are eukaryotic organisms, which means their cells contain nuclei. Some fungi, such as mushrooms, are multicellular. Others such as yeast, are unicellular. Fungi have cell walls. But unlike plants, their cell walls are made of chitin and glucans. Chitin is a polysaccharide that's found in abundance, especially in arthropods. Glucan is a polysaccharide comprised of glucose units linked together.

What are fungi?

Fungi are one of the major kingdoms of organisms. They aren't plants, partly because they have cell walls surrounding each cell, and they're immobile. So, fungi form a separate kingdom of organisms.

Fragmentation (fungi)

Fungi can grow from small fragments of hyphae. Fungal mycelium may break apart while animals graze or during natural events, such as storms. Parts of broken mycelium can form a separate fungus. The newly developed fungus is genetically identical to the original fungus.

Spore formation

Fungi can undergo asexual and sexual reproduction by forming haploid spores. Asexual reproduction involves spores from the mycelium of only one parent. But sexual reproduction needs two different mycelia to occur.

Fungi nutrition

Fungi, unlike plants, lack chlorophyll. So, they can't photosynthesize to create their own food. Because fungi rely on other food sources for nutrition, they're heterotrophic. Fungi can't digest food internally. They first digest their food externally, and then absorb the nutrients. Fungi produce enzymes to break complex food into simple nutrients. Their widespread mycelium then easily absorbs the nutrients.

Gymnosperms:

Gymnosperms are plants that don't bear flowers or fruits. Their seeds can be seen on their leaves or scaly barks. Conifers, cycads, and ginkgoes belong to this group. ome gymnosperms have specialized structures called cones that contain seeds. They also contain reproductive structures. The male reproductive structure, the microspore, produces microgametophyte, the male gamete. The female reproductive structure, the megaspore, produces the female gamete, megagametophyte. The gametes fuse to form seeds.

Gravitropism:

In gravitropism, plants grow in response to gravity. Roots of the plant exhibit positive tropism by growing downward, in the direction of gravity. Shoots of the plant demonstrate negative tropism by growing upward, against the direction of gravity.

Aseptate hyphae in fungi

In the hyphae of other fungi, the cells don't go through the process of cytokinesis, the final stage of cell division that causes the two daughter cells to break apart. As a result, the hyphae lack septa. These aspetate fungi have free-flowing nuclei and organelles.

Presence of Hyphae in fungi

Multicellular fungi are made of thin, microscopic filaments called hyphae. These hyphae increase in length and branch out. They entwine with each other to form a large network called mycelium. In mushrooms, the mycelium lies underground, where it spreads to absorb nutrients. The part we see above ground is the fruiting body that helps fungus reproduce.

Mutualistic fungi:

Mutualistic fungi feed on living plants while also helping them. These plant-fungi associations are called mycorrhizae. In a mycorrhiza, a fungus provides nutrients and carbon dioxide to a plant. In return, the plant provides support, oxygen, and sugar to the fungus. So, the fungus forms a mutually beneficial relationship with the plant.

Nonvascular Plants

Nonvascular plants don't have vascular tissue to transport nutrients. As a result, they absorb nutrients through diffusion and osmosis. These plants grow to a shorter height to facilitate diffusion and distribution of nutrients to all parts. Bryophytes are a type of nonvascular plant that includes mosses, liverworts, and hornworts. They live in diverse habitats, from arid areas to damp places. Bryophytes have small, leaf-like structures sprouting from their stems. They also possess root-like structures called rhizoids. Rhizoids act as an anchor, and absorb water and nutrients from the soil.

Vascular Plants with Seeds

Other types of vascular plants produce viable seeds that can later germinate and grow into a mature plant. Scientists have further classified these plants into angiosperms and gymnosperms, depending on their ability to bear flowers. Let's discuss these plants briefly.

epidermis

Terrestrial plants have an outer covering called the epidermis. The epidermis consists of pores called stomata. Most stomata lie on the underside of leaves. They are used in gas exchange during photosynthesis. Similarly, stomata also help in a process called transpiration. During transpiration, absorbed water travels up the leaf, where it evaporates into the surroundings through stomata.

Septate hyphae in Fungi

The hyphae in some fungi cross walls called septa. They divide the hyphae into distinct divisions, creating cells. Each septum is comprised of small openings or pores, which help exchange nutrients, cytoplasm, organelles, and in some cases, nuclei between cells.

Leafs

The leaf is the main site of photosynthesis for plants. During this process, plants take in carbon dioxide and release oxygen. During cellular respiration, they take in oxygen and release carbon dioxide, while converting chemical energy into ATP (adenosine triphosphate).

Stems

The stem is the part of a plant that supports the leaves and the reproductive structures. Plants have several different types of stems.

Plant Responses

Tropism is a plant's growth response that results in turning toward or away from the stimulus. Tropism can be either positive, which involves turning toward the stimulus, or negative, which results in turning away from the stimulus.

Budding in Fungi

Unicellular fungi such as yeast grow asexually by budding. During budding, the yeast DNA divides equally, while the cytoplasm divides unequally. This division leads to a smaller outgrowth called a bud. The bud gradually detaches from the parent cell. This new yeast cell is genetically identical to the parent yeast cell.

Vascular Plants

Vascular plants have specialized vascular tissue that transport water and nutrients to all parts of the plant. For this reason, vascular plants grow taller compared to nonvascular plants. Scientists classify vascular plants based on the presence of seeds.

Vascular Plants Without Seeds:

Vascular plants that don't have seeds don't produce flowers or fruits and, therefore, don't bear seeds. Pteridophytes belong to this group.

What are roots made of?

he root is made of three layers—the epidermis, the cortex, and the stele. The epidermis is the outermost layer. It has root hair, which helps to absorb water. The cortex is the middle layer that contains cells that transport and absorb substances. The stele is the innermost layer of the root. It consists of vascular tissues.