Answer:
Plastics are made from natural materials such as cellulose, coal, natural gas, salt and crude oil through a polymerisation or polycondensation process. Plastics are derived from natural, organic materials such as cellulose, coal, natural gas, salt, and crude oil.
Answer:
d.The wing-assisted incline running theory postulates that wings were initially used to maintain balance while climbing up slopes.
Explanation:
Two theories were given to explain the origin of avian flight. The top-down theory suggested that the birds' ancestors were tree dwelling species. They took help of wings to glide from tree to tree in order to avoid predator or catch prey. The bottom up theory suggested that the birds' ancestors were ground dwelling species. They took help of wings to maintain a balance and provide a lift for efficient running.
Wing-assisted incline running was a mixture of both the above theories and gave a balanced view point. According to it, birds' ancestors used wings to maintain a balance while running up inclined slopes. The wings helped them to save energy while scaling slopes and eventually a flight mechanism was also developed.
Answer:
The human population is yet to reach its carrying capacity. However, the following will suggest that humans have reached their carrying capacity.
1. When humans are unable to increase food production which is expected to sustain a larger population.
2. When humans' use of resources, in general, is greater than resource availability.
Explanation:
The human population is yet to reach its carrying capacity. However, the following will suggest that humans have reached their carrying capacity.
1. When humans are unable to increase food production which is expected to sustain a larger population.
2. When humans' use of resources, in general, is greater than resource availability.
Answer:
Fusion of embryonic myoblasts, each having its own nucleus to many other myoblasts to form the multinucleated skeletal muscle fibers.
Explanation:
The multiple nuclei in skeletal muscle cells are as a result of fusion of embryonic myoblasts, each having its own nucleus to many other myoblasts to form the multinucleated skeletal muscle fibers. This gives rise to multiple copies of genes, allowing production of the large amounts of proteins and enzymes and ATPs needed for muscle contraction.
