Answer:
Main sequence stars change into giant star by exhausting their hydrogen supply.
Explanation:
This fact explain that main sequence stars change into giant star by exhausting their hydrogen supply. A main sequence star burns due to the presence of hydrogen in its core, because of this burning the main sequence reaching the end of its life cycle. Then the pressure of fusion reaction provides an outward thrust that expands the star many times larger than its original size, that leads to the formation of a red giant.
Nerve cells or neurons are, fundamentally, cells of the nervous system, they are responsible for the transmission of nerve impulses and communicate with one another through connections called synapses .
Neurons are typical of all vertebrates, although in the rest of the animal kingdom there are other cells that have similar functions.
So, the right answer is A. Horse.
Answer:
Plants take in carbon and let out oxygen.
Explanation:
Carbon and cellular respiration has to do with those cycles because plants which do cellular respiration as well as all living things take in either oxygen or carbon and let either one of them out.
Answer:
1. 20 units
2. 4 units
Explanation:
In an ecosystem, energy is transferred from one organism occupying a trophic level to another as they feed on one another. The amount of energy that is being transferred as the chain progresses is called ECOLOGICAL EFFICIENCY. According to this question, the ecological efficiency at each trophic level of the ecosystem is 20%. This means that about 20% of energy units will be transferred to the next trophic level.
If the green plants of the ecosystem capture 100 units of energy, the amount of energy that will be available to support herbivores (plant eaters) is: 20% × 100units i.e. 20/100 × 100 = 20 units.
Also, the amount of energy that will be available to support carnivores subsequently will be 20% of 20 units i.e. 20/100 × 20 = 4 units.
The correct answer is: (a) RNA polymerase (along with its sigma subunit) can initiate transcription on its own.
More differences between prokaryotic and eukaryotic transcription:
• In prokaryotes transcription occurs in the cytoplasm (unlike in eukaryotes in nucleus) and it is simultaneous with translation,
• In prokaryotes there is only one type of RNA polymerase (in eukaryotes there are three types of them).
• There is no sigma subunit in eukaryotes, the initiation of transcription begins thanks to initiation factors.
• Promoter region in prokaryotes contains pribnow box, while in eukaryotes it contains TATA and CAT box.
