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.
Answer:
recombinant DNA
Explanation:
In molecular biology, recombinant DNA molecules are genetic sequences formed by combining DNA material from different sources (i.e., organisms, populations, species, etc). Proteins produced from DNA recombinant molecules are known as recombinant proteins. Molecular cloning is the most widely used technique in molecular biology in order to produce recombinant DNA molecules. In this technique, a cloning vector such as, for example, a plasmid of a bacterium, is used to insert a foreign DNA fragment into another cell which is then expressed in the host cell.
With shorter necks, giraffe ancestors could not reach food-containing branches on tall trees. This resulted in the directional selection of giraffes with longer necks.
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Why is choosing a direction necessary? </h3>
It nearly appears obvious that the giraffe's long neck developed as a result of a lack of food in the lower branches of trees. The giraffe has a significant advantage because it is taller than any other mammal and can feed where few others can.
When compared to modern giraffes, the giraffe's ancient predecessors had a shorter neck. The plants that were lying at a higher level were inaccessible to them. Giraffe phenotypes have changed in various ways, and now have long necks to reach vegetation that is higher up. The extreme form is chosen above other features in directional selection. It was decided to choose the long-necked giraffe over the short-necked.
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