Answer:
A mutation is generally referred to as certain alternations in the gene whether it may be DNA sequences, which may be beneficial, harmful or of no significance to the mutant gene bearing organisms.
Explanation:
- A mutation that increases the ability to store moisture in a dry environment is obviously beneficial. Because it prevents dehydration and maintains normal functioning in spite of adverse conditions.
- A color mutation that decreases a bird's chances of sexual selection is beneficial in the sense that it prevent certain abnormalities in offspring like sexual dimorphism. Also sexual selection often proves to be a threat to the survival of the organisms as per handicap principle.
- A mutation in non coding region of DNA is harmful, as it is often observed to facilitate expression of wrong proteins at inappropriate places.
- A mutation in the that does not changes protein synthesis increased white pigmentation on a prey animal in snowy environment as it had prevented adaption of the prey and hence harmful for survival of it.
- A mutation decreasing plant's height in competition to light, makes them less exposed to sun energy important for photosynthesis and hence it is harmful for the plant.
Answer:
Many Middle Eastern countries have been transitioning from largely rural living to urban living. City populations are growing quickly as people move to find jobs. However, environmental problems have come with this rapid urbanization. Many urban areas are experiencing air and water pollution. Air pollution is occurring due to the region's reliance on toxic energy sources, oil and gas. Oil and gas release emissions into the air when consumed by factories or cars. Cities are also experiencing water pollution issues due to a lack of waste treatment options. Without places to dispose of waste, people are dumping sewage and industrial waste into water sources. Finally, urban coastal areas are having problems with coastal degradation. Soil erodes and wildlife habitats are destroyed as land is changed for urban development.
Explanation:
This is called a template strand because it is used as a "template"
Answer:
- Calcium binds to troponin C
- Troponin T moves tropomyosin and unblocks the binding sites
- Myosin heads join to the actin forming cross-bridges
- ATP turns into ADP and inorganic phosphate and releases energy
- The energy is used to impulse myofilaments slide producing a power stroke
- ADP is released and a new ATP joins the myosin heads and breaks the bindings to the actin filament
- ATP splits into ADP and phosphate, and the energy produced is accumulated in the myosin heads, starting a new cycle
- Z-bands are pulled toward each other, shortening the sarcomere and the I-band, producing muscle fiber contraction.
Explanation:
In rest, the tropomyosin inhibits the attraction strengths between myosin and actin filaments. Contraction initiates when an action potential depolarizes the inner portion of the muscle fiber. Calcium channels activate in the T tubules membrane, releasing <u>calcium into the sarcolemma.</u> At this point, tropomyosin is obstructing binding sites for myosin on the thin filament. When calcium binds to troponin C, troponin T alters the tropomyosin position by moving it and unblocking the binding sites. Myosin heads join to the uncovered actin-binding points forming cross-bridges, and while doing so, ATP turns into ADP and inorganic phosphate, which is released. Myofilaments slide impulsed by chemical energy collected in myosin heads, producing a power stroke. The power stroke initiates when the myosin cross-bridge binds to actin. As they slide, ADP molecules are released. A new ATP links to myosin heads and breaks the bindings to the actin filament. Then ATP splits into ADP and phosphate, and the energy produced is accumulated in the myosin heads, which starts a new binding cycle to actin. Finally, Z-bands are pulled toward each other, shortening the sarcomere and the I-band, producing muscle fiber contraction.
