Biology (Medical Entrance)

Xerochasy is dehiscence that occurs upon drying and its seen in funaria.
 

Bryophytes are also called non vascular cryptogams because vascular tissues are absent in them.Bryophyte is a traditional name used to refer to all embryophytes (land plants) that do not have true vascular tissue and are therefore called "non-vascular plants".Some bryophytes do have specialized tissues for the transport of water. Since these do not contain lignin, they are not considered to be true vascular tissue.
 

A virion is a complete viral particle consisting of RNA or DNA surrounded by a protein shell, constituting the infective form of a virus.

Lichens are plant like organisms, under a microscope the association is seen to consist of millions of cells of algae (called the phycobiont) woven into a matrix formed of the filaments of the fungus (called the mycobiont).

Viruses typically store their genetic information encoded in molecules of either DNA or RNA -- either one or the other but not both.

African trypanosomiasis is a parasitic disease transmitted by the tsetse fly. It gets its nickname ‘sleeping sickness’ because symptoms can include a disturbed sleep pattern.

When food runs out and they are ready to form sporangia, they do something radically different. They release signal molecules into their environment, by which they find each other and create swarms. These amoeba then join up into a tiny multicellular slug-like coordinated creature, which crawls to an open lit place and grows into a fruiting body. Some of the amoebae become spores to begin the next generation, but some of the amoebae sacrifice themselves to become a dead stalk, lifting the spores up into the air.

Pseudopodia are formed by microtubule and filament structures. The cell surface projects a membrane process called the lamellipodium, which is supported inside by filaments that form at the leading edge, turning into networks as they merge. Cytoplasm flows into the lamellipodium, forming the pseudopodia.

Gram-positive bacteria take up the crystal violet stain used in the test, and then appear to be purple-coloured when seen through a microscope.

Heterocysts are specialized nitrogen-fixing cells formed during nitrogen starvation by some filamentous cyanobacteria, such as Nostoc punctiforme, Cylindrospermum stagnale, and Anabaena sphaerica.

Trichonympha is a genus of parabasalid protists that live in the intestines of many, if not most, termite species. They are symbiotes, in that they break down the cellulose in the wood and plant fibers their hosts eat.

Surface appendages used by bacteria for attachment to another bacteria and host organisms, are called pili.

Bacillus species are aerobic, sporulating, rod-shaped bacteria that are ubiquitous in nature.

Plant transformation mediated by Agrobacterium tumefaciens, a soil plant pathogenic bacterium, has become the most used method for the introduction of foreign genes into plant cells and the subsequent regeneration of transgenic plants.

Ciliates have two different sorts of nuclei: a small, diploid micronucleus (reproduction), and a large, polyploid macronucleus (general cell regulation). The latter is generated from the micronucleus by amplification of the genome and heavy editing. The micronucleus serves as the germ line nucleus, but does not express its genes. The macronucleus provides the nuclear RNA for vegetative growth.

When conditions become unfavorable, these slime molds form sporangia - clusters of spores, often on the tips of stalks.

Euglena is a large genus of unicellular protists, which have both plant and animal characteristics. All are motile by means of a flagellum (animal characteristic). Most have chloroplasts (alga and plant characteristic).

Kingdom is the largest unit of biological classification. In the animal kingdom, the term phylum is used instead of division , in the plant kingdom.

Methanogenesis or biomethanation is the formation of methane by microbes known as methanogens. Organisms capable of producing methane have been identified only from the domain Archaea, a group phylogenetically distinct from both eukaryotes and bacteria, although many live in close association with anaerobic bacteria.

Pteridophytes differ from bryophytes in having plant body is either leafy or thalloid.Plant body is differentiated into root, stem and leaves
The cells in plant body are diploid.

Each peristome is a ring of triangular "teeth" formed from the remnants of dead cells with thickened cell walls. There are usually 16 such teeth in a single peristome, separate from each other and able to both fold in to cover the stoma as well as fold back to open the stoma.

Certain viruses, particularly bacteriophages, are called temperate (or latent) because the infection does not immediately result in cell death. The viral genetic material remains dormant or is actually integrated into the genome of the host cell.

Euglenoid species that have chlorophyll are facultative heterotrophs in the absence of light or in abundance of dissolved food outside.

The families having common characters constitute a/an order.

Dhoop and Hawan samagries are prepared from a lichen called Ramalina.

A species is often defined as the largest group of organisms in which two individuals are capable of reproducing fertile offspring, typically using sexual reproduction.

Genus is a group of similar and related species.

In bryophytes the sporophyte is attached and dependent upon the gametophyte for nutrition i.e. is parasitic on the gametophyte.

Bacteriophages, also known as phages, are viruses that infect bacteria. These phages also require a bacterial host in order to replicate themselves. Bacterial viruses, as these are also often called, are made up of proteins that coat an inner core of nucleic acid – either DNA (deoxyribonucleic acid) or RNA (ribonucleic acid). Phages also vary in structure, ranging from the simple to the more elaborate and complex.

Chrysophytes are plant-like protists that can be found in marine and freshwater environments which are often low in calcium. There are three main types of chrysophytes: diatoms (bacillariophyta), golden-brown algae (chrysophyceae), and yellow-green algae (xanthophyceae).

The enzymes involved in viral replication are synthesized by the host cell.

Unlike most other protozoans, sporozoans have no cilia or flagella. All species are parasitic and have elaborate life cycles, often requiring more than one host. The best-known sporozoan is Plasmodium falciparum, the causative organism of malaria.

Litmus is a water soluble mixture of different dyes extracted from lichens. It is often absorbed onto filter paper to produce one of the oldest forms of pH indicator, used to test materials for acidity.

Slime molds are classified under the Kingdom Protista.They are motile like animals but some are unicellular so they can not be classified as animals. Slime molds are an odd-ball group, so like other odd-balls, they get thrown in with the protists.

A virus consists of a single- or double-stranded nucleic acid and at least one protein surrounded by a protein shell, called a capsid; some viruses also have an outer envelope composed of fatty materials (lipids) and proteins.