Flagellum is primarily a motility organelle that enables
movement and chemotaxis. Bacteria can have one
flagellum or several, and they can be either polar (one or
several flagella at one spot) or peritrichous (several
flagella all over the bacterium).
Answer:
Luminosity in relation to stars would be the amount of light emmited by a star in a unit of time.
Explanation:
*Genetic determinism of sexes
*Two types are known.
I. Drosophila met at mammals , insects and some plants.
a) Chromosomes have notation:
Masculine ⇒ xy
Feminine⇒xx
II. Abraxas met at amphibians,reptiles,birds and fish.
a) Chromosomes have notation:
Masculine⇒xx
Feminine⇒xy
Answer:
Primary succession occurs in areas without any soil where basically nothing is there. After an event such as a volcanic eruption, pioneer species such as lichens and mosses are able to colonize the land since they can grow without soil and are primitive. Lichens can break down rock to form soil and they can add small amounts of organic matter to the rocks when they decompose to make even more soil. Simple plants like ferns can then grow in the created soil. After these simple plants die, more organic material is added to the soil and the soil thickens, allowing grasses, wildflowers, and other plants to begin to take over. Next, after these plants die, enough nutrients are added to the soil for trees and shrubs to survive. Finally, insects, small birds, and mammals begin to move into the area and form a community, so what was once bare rock can now support a variety of life.
Answer:
They have uncoiled to form long, thin strands.
Explanation:
Chromosomes are present in cell nucleus and consist of chromatin. Genes are present in linear order on chromosomes. The chromosomes become visible under the microscope as distinct structures during cell division. When cells are not dividing, the chromosomes decondense to loose their individuality and make the mass of chromatin.
Chromatin is complex of DNA and packing proteins. As the cells enter the prophase stage of cell division, condensation of chromatin occurs and individual chromosomes become visible under microscope. Before that (during interphase), chromosomes are not visible as they are present in decondensed form.
