A closed system is a system that makes no physical or chemical exchanges with its environment. Of these systems provided as choices (tree, human, clock, car), only a clock does not make exchanges with the environment, except for energy.
Therefore, of that list, only a clock would be a closed system.
Hope that helped! =)
Answer:
The number of primary consumers will increase
Explanation:
If all the secondary consumers disappear, the primary consumers will continue to reproduce causing the population to increase
A
A haploid cell formed in the male seminiferous tubules
The reproductive tissues of male and female humans develop similarly in utero until a low level of the hormone testosterone is released from male gonads. Testosterone causes the undeveloped tissues to differentiate into male sexual organs. Primitive gonads become testes; other tissues produce a penis and scrotum in males.
Answer:
A theory is the most logical explanation of events that occur in nature. The explanation often results from the use of the scientific method. First, a problem must be stated. Then, after gathering information, a hypothesis, or logical solution, is formed. The solution is then tested in an experiment. The factor that is tested in an experiment is called the variable. This factor is not contained in the control setup. Sometimes principles of chemistry, the study of how substances change and combine, are involved in experiments. At other times, principles of physics are instead.
The metric system is used for all measurements in science. Some basic units in this system are the liter for volume, the kilogram for mass, the degree Celsius for temperature, and the meter for length. Sometimes, the density of a substance, or its mass per unit volume must be measured. If dimensional analysis is needed, a conversion factor must be used.
Explanation:
<span>Forebrain. Forebrain is related to functions of cognitive activities. It is part of brain with other two parts which are hind brain and mid brain. Amygdala related to emotions. Midbrain related to vision, hearing etc. while hindbrain is concerned with control involuntry functions like respiration.</span>