Definition: "Copying of information from DNA to RNA which exit nucleus is known as transcription"
Explanation: Transcription is a vital process for living organisms, because it is a staring point for protein synthesis. It occurs inside the nucleus and is carried out by RNA polymerase enzyme. In eukaryotes RNA pol is of three types: these are RNA Pol 1, RNA Pol 2, and RNA Pol 3. In prokaryotes it is of only one type.
Steps in transcription: Transcription consists of three main steps
1. Initiation: In this step RNA pol attach to DNA template at 5 prime end in the promoter region to start the formation of complementary strand of RNA. In prokaryotes there is a region called
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Pribnow box, with the </span>consensus sequence<span> TATAAT present about 10 base pair away from site that serves as a transcription initiation. In eukaryotes the promoter region is more complex it contain activator and enhancer.
2. Strand elongation: </span><span>Once transcription is initiated, the DNA double helix unwinds and RNA polymerase reads the template strand, adding nucleotides to the 3′ end of the growing chain.
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3. Transcription Termination:
Terminator sequences are found close to the ends of non-coding sequences. Before termination polyadenylation occurs. <span>
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In certain organisms, like humans, there are two morphologically distinct types of gametes: (1) the male gamete (i.e. sperm cell) and (2) the female gamete (i.e. ovum). The male gamete is smaller in size and motile whereas the female gamete is several times bigger and non-motile. The haploid condition of the two gametes is essential so that at fertilization during sexual reproduction the integrity of the chromosomal number is maintained throughout generations.
Hope this helps.
The answer is: B - Mitochondria
Explanation:
The mitochondria is the powerhouse of the cell.
The main function of the mitochondria is to provide energy for cellular activity by the process of aerobic respiration. In this process, glucose is broken down in the cell's cytoplasm to form pyruvic acid, which is transported into the mitochondrion.