There are three major known groups of Archaebacteria: methanogens, halophiles, and thermophiles. The methanogens are anaerobic bacteria that produce methane. They are found in sewage treatment plants, bogs, and the intestinal tracts of ruminants. Ancient methanogens are the source of natural gas. Halophiles are bacteria that thrive in high salt concentrations such as those found in salt lakes or pools of sea water. Thermophiles are the heat-loving bacteria found near hydrothermal vents and hot springs. 

Mesosome is a convoluted membranous structure formed in a prokaryotic cell by the invagination of the plasma membrane. Its functions are as follows:
(1) These extensions help in the synthesis of the cell wall, replication of DNA. They also help in the equal distribution of chromosomes into the daughter cells.
(2) It also increases the surface area of the plasma membrane to carry out various enzymatic activities.
(3) It helps in secretion processes as well as in bacterial respiration.

 The presence of synovial fluid, between articulating surface of the two bones enclosed within synovial cavity of synovial joints to makes our joints to function without grinding noise and pain. The bone joints function without grinding noise and pain because the end of the bones are covered by the articular cartilage which allows easy movement of the bones against each other.

Divergent evolution describes the accumulation of distinct traits that can lead to speciation events. A large population consists of a single ancestor species. Over time, different groups of the population come to inhabit different niches and develop traits for specialized inhabitance of that niche. As these changes accumulate, the population slowly develops distinct groups. When these groups can no longer reproduce due to some sexual barrier, a speciation event has occurred. This process aligns with the theory of evolution for Darwin's finches.

Euglenoids

1. Mostly freshwater
2. Motile, flagellate
3. They lack cell wall.
4. Most euglenoid are photosynthetic but some are heterotrophic.
5. They have single stage in life cycle which is mobile.

Slime molds

1. They are found in moist terrestrial habitat.
2. Slime molds have complex life cycle, in some stages they are motile but in some stage they are immobile.
3. They possess cell wall.
4. Heterotrophic
5. ​Slime molds have two stages in life i.e free living and slug stage

Herbarium is “a collection of plant specimens which have been dried and pressed and arranged in the sequence of an accepted classifications”. It forms a store house for future use. The preparation of Herbarium involves following steps :
(1) Collection of Specimens : It is a field work. For collection one has to get information about the area, habitat, season and the time of collection. There is a requirement of digger for digging roots, scissors for cutting twigs, knife for woody twigs and a pole with a hook for collection.
(2) Drying and Pressing : After collection, the plants are dried up by keeping them between the folds of old newspapers. The plants, after (hying, are pressed up by a set of two broads straps.
(3) Mounting : The dried specimens are pasted on the herbarium sheets of standard size (29 X 41 cm). The specimens are fixed on the sheets by applying glue or adhesive.
The specimens are sprayed with fungicides like 01% solution of mercuric chloride and pesticides like DDT, naphthalene to check fungal growth and insects infections.
(4) Labelling : Labelling should be done with mounting. It should bear the botanical name, family, locality, data of collection with the habit of the plant specimen. The name of the collector or the person should also be given.
(5) Storage : The sheets are arranged according to classification. They are stored in disinfected metallic cupboards. The information about the collected specimens-is compiled and published in the form of a book.

Herbarium is “a collection of plant specimens which have been dried and pressed and arranged in the sequence of an accepted classifications”. It forms a store house for future use. The preparation of Herbarium involves following steps :
(1) Collection of Specimens : It is a field work. For collection one has to get information about the area, habitat, season and the time of collection. There is a requirement of digger for digging roots, scissors for cutting twigs, knife for woody twigs and a pole with a hook for collection.
(2) Drying and Pressing : After collection, the plants are dried up by keeping them between the folds of old newspapers. The plants, after (hying, are pressed up by a set of two broads straps.
(3) Mounting : The dried specimens are pasted on the herbarium sheets of standard size (29 X 41 cm). The specimens are fixed on the sheets by applying glue or adhesive.
The specimens are sprayed with fungicides like 01% solution of mercuric chloride and pesticides like DDT, naphthalene to check fungal growth and insects infections.
(4) Labelling : Labelling should be done with mounting. It should bear the botanical name, family, locality, data of collection with the habit of the plant specimen. The name of the collector or the person should also be given.
(5) Storage : The sheets are arranged according to classification. They are stored in disinfected metallic cupboards. The information about the collected specimens-is compiled and published in the form of a book.