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! =)
The answer is D.rainforest. it is a very complex ecosystem with variety of plants and animals.
The diploid number is restored when the two haploid cells combine to create a zygote. Basically when the sperm cell enters the egg cell and makes the offspring.
A solid minute object that is said to come together for the formation of the planet and are believed to produce cosmic dust are called planetesimal.
The options that best describes the planetesimals are:
- Option A. They are the origins of planets.
- Option B. They formed from gas and dust.
- Option D. They are believed to have developed in debris disks.
The descriptions can be explained as:
- It is believed that planets formation occurred through planetesimals. The formation happened from gas, dust particles and debris.
- By the process of accretion, the discs coalesced and became bigger and solid over time. This bigger mass started attracting other matters towards each other because of gravitational force.
- This pull resulted in either breaking or creation a bigger mass of pieces known as planetesimals. The collision continued to become bigger and solid planets we know today.
Therefore, options A, B and D are correct.
To learn more about planetesimals refer to the link:
brainly.com/question/10337322
Answer:
invasive species are a problem both in anthropogenically altered and natural environments
Explanation:
An invasive species can be defined as a non-native species introduced into a new environment which then becomes abundant. Only in the US, it is believed that there are approximately 4,000 invasive species (some examples include the feral pigs, grey squirrels, European rabbits, etc.). In general, invasive species have a negative impact on the ecosystem, especially by displacing native species and thereby altering the trophic chain. In anthropogenically altered environments (anthromes), human beings are considered to be an invasive species.
