The correct answer is (B) Photosynthesis and diffusion from the air
Dissolved oxygen enters the water from photosynthesis and through air. The The aeration of water can be caused by wind. From the air oxygen diffuse into the water and gets mixed in the it through circulation. The oxygen is also produced as a waste product of photosynthesis from blue-green algae, phytoplankton, etc which is added in water.
Long one hope this helps!
A command economy is one in which a centralized government controls the means of production. The government determines what is produced, how it is produced and how it is distributed. Private enterprise does not exist in a command economy. The government employs all workers and unilaterally determines their wages and job duties. There are advantages and disadvantages of command economy structures. Command economy advantages include low levels of inequality and unemployment and the common good replacing profit as the primary incentive of production. Command economy disadvantages include lack of competition and lack of efficiency.
A command economy is one in which a centralized government controls the means of production. The government determines what is produced, how it is produced and how it is distributed. Private enterprise does not exist in a command economy. The government employs all workers and unilaterally determines their wages and job duties. There are advantages and disadvantages of command economy structures. Command economy advantages include low levels of inequality and unemployment and the common good replacing profit as the primary incentive of production. Command economy disadvantages include lack of competition and lack of efficiency.
Unlike the invisible hand of the free market, which cannot be manipulated by a single company or individual, a command economy government can set wages and job openings to create an unemployment rate and wage distribution that it sees fit.
Whereas the motivation for profit drives most business decisions in a free market economy, it is a non-factor in a command economy. A command economy government, therefore, can tailor products and services to benefit the common good without regard to profits and losses. For example, most true command economy governments, such as Cuba, offer free, universal health care coverage to their citizens.
Command economies sit at a disadvantage as their inherent lack of competition hinders innovation and keeps prices from resting at an optimal level for consumers. Although those who favor government control criticize private firms that esteem profit above all else, it is undeniable that profit is a great motivator and drives innovation. For this reason, most advancements in medicine and technology have come from countries with free market economies, such as the United States and Japan.
Efficiency is also compromised when the government acts as a monolith, controlling every aspect of a country's economy. The nature of competition forces private companies in a free market economy to minimize red tape and keep operating and administrative costs to a minimum. If they get too bogged down with these expenses, they achieve lower profits or have to raise prices to meet expenses; ultimately, they are driven out of the market by competitors capable of operating more efficiently. Production in command economies is notoriously inefficient as the government feels no pressure from competitors or price-conscious consumers to cut costs or streamline operations.
Answer;
Cell
Explanation;
-The biological levels of organization of living things arranged from the simplest to most complex are: organelle, cells, tissues, organs, organ systems, organisms, populations, communities, ecosystem, and biosphere.
-Cell is the basic unit and building block of life. It is bound by a cell membrane, and possesses a nucleus which acts as its brain. Arachnoidiscus ehrenbergi is an example of diatoms which are unicellular, therefore it is a cell.
Answer:
The given statement is false.
Explanation:
The mammals can be differentiated into three main groups on the basis of the development of their babies. These three groups are marsupials, monotremes, and placental mammals, which is the largest group. The monotremes refer to the mammals, which lay eggs. The marsupials refer to the mammals, which give birth to young ones that are not developed completely. While in a placental mammal, the development takes place within the body of a mother until and unless its systems of the body start to work on their own.