The correct answer is: c. Transcription
Transcription is the first step of gene expression in which DNA molecule is copied (transcribed) into RNA (mRNA) by RNA polymerase. The process of transcription is divided into three phases:
1. Initiation
• RNA polymerase with transcriptional factors bind to gene promoter
• RNA polymerase unwinds DNA double helix (transcription bubble is formed)
2. Elongation
• RNA polymerases adds nucleotides complementary to DNA
3. Termination
• RNA polymerase gets to stop codon (transcribes a sequence of DNA known as a terminator)
• Formed complementary RNA strand is released from DNA-RNA complex
Answer:
option 1
Explanation:
In assemblying the nucleosome, this reaction occurs in two main steps. the H3 and H4 are recruited first to the DNA in pairs forming the H3/H4 tetramer; meaning two of H3 and two of H4. This gives rise to the nucleosome precursor. Then after this, the dimers of both H2A/H2B are recruited to this precursor, to give rise to the octamer structure around which the DNA is wrapped.
Answer:
Hormones act as first messenger but not as second messengers.
Explanation:
Second messenger act as signaling molecule which are secreted in response to various biological signals generated by first messenger such as hormones,neurotransmitters etc.Second messengers include various bioactive molecules such as cyclic AMP(cAMP),cyclic GMP(cGMP),inositol triphosphate(IP3),diacylglycerol(DAG),calcium ions(Ca2+) etc.
Hormones are extracellular signaling molecules whereas second messengers are intracellular signaling molecules.
C. Hapliod, and are made when haploid spores undergo mitosis
