Answer:
Microevolution refers to evolution at or below the species level.
Explanation:
- If the change occurs in the short period span of time within the specific species then this type of change is refereed to as the micro evolution.
- Micro evolution is occurred in between small group of animals or species.
- If the evolution is expanded to community or large population it is not considered as a microevolution.
- Microevolution may be caused due to mutation, selection, gene flow and genetic drift.
Answer:
Miasma theory was replaced because John Snow collected data that showed that germs cause disease.
Explanation:
The theory of miasma was proposed in the past when some scientists —like doctors Thomas Sydenham and Giovanni Maria Lancisi— thought that disease was the product of emanations originated by the decomposition of organic matter. This theory was based on the fact that diseases predominated in places with poor hygienic conditions.
John Snow, an english physician, was one of the main contributors to the <u>microbial theory of disease</u>. In 1854, while a cholera epidemic was occurring, he collected data and organized it statistically and then concluded that the disease was caused by germs present in drinking water. This <u>data was contrary to the miasma theory, which would eventually be displaced by the microbial theory of the disease</u>.
Answer:
Sarcomere
Explanation:
The muscle fiber / myofibrils consist of 2 types of filaments - actin and myosin. The myosin filaments are thick filament whereas the actin filaments are the thin filament.
In addition to this, the muscles have A-band and I-bands. These bands give the muscles alternate light and dark colour band structure. In the A-band, myosin filaments are present, whereas in the I - band the actin filaments are found.
In I-band 2 Z-lines are located. The area between the Z-lines is called sarcomere. In this sarcomere region both actin and myosin filaments present.
When muscles get contracted the length of the sarcomere shorten. The actin and myosin filaments overlap in this area. A cross-bridge form between them, with the help of filamentous protein titin.
There is less diversity hope this helps