The gene for a-globin is present in all vertebrate species. Over millions of years, the DNA sequence of this gene has changed in the lineage of each species. Consequently, the amino acid sequence of a-globin has also changed in these lineages. Among the 141 amino acid positions in this polypeptide, human a-gobin differs from shark a-globin in 79 positions; it differs from carp a-globin in 68 and from cow a-globin in 17. Do these data suggest an evolutionary phylogeny for these vertebrate species?

Answer: Yes, these data suggest an evolutionary phylogeny for these vertebrate species. Explanation: Gene is similar to meaningful word and DNA is similar to sentence. The meaning of a word is same as protein. Building blocks of proteins are the amino acids. Formation of proteins depends on the instructions in the gene. It gives information […]

RNA is synthesized using DNA as a template. Is DNA ever synthesized using RNA as a template? Explain.

Answer: Yes, DNA ever synthesized using RNA as a template by reverse transcription process. Explanation: RNA is synthesized using DNA as a template is called transcription. Transcription means formation of mRNA from DNA and mRNA carries the information which is required for protein synthesis. Reverse transcription is the process in which DNA is synthesized from […]

What is the difference between transcription and translation?

Transcription means formation of mRNA from DNA and mRNA carries the information which is required for protein synthesis. Translation is the process of synthesis of protein from mRNA. In eukaryotes tanscription and translation occur in different cellular compartments that are separated by a membrane barrier such as transcription occurs inside the nucleus and translation occurs […]

The template strand of a gene being transcribed is CTTGCCAGT. What will be the sequence of the RNA made from this template?

Answer: GAACGGUCA Explanation: Transcription is the process of production of RNA molecule from DNA sequence of a gene. Out of two DNA strands, one strand acts as the template strand that runs in a 3′ to 5′ direction and is used for synthesis of a complementary RNA transcript. Other strand acts as the coding strand runs […]

The gene contains 141 codons. How many nucleotides are present in gene’s coding sequence? How many amino acids are expected to be present in the polypeptide encoded by this gene?

Answer: 423 nucleotides and 141 amino acids. Explanation: One amino acid = one codon = three nucleotides. Codon is defined as set of instructions which are the sequence of 3 nucleotides. They together form a unit of genetic code. As each group of 3 nucleotides codes 1 amino acid. Therefore, 3 × 141 = 423 […]

The sequence of a strand of DNA is ATTGCCGTC. If this strand serves as the template for DNA synthesis, what will be the sequence of newly synthesized strand?

Answer: TAACGGCAG Explanation: A newly synthesized strand contains nucleotides that are complementary to those in the template sequence. Bases are present in DNA are adenine (A), thymine (T), cytosine (C), and guanine (G). Adenine and guanine are purines. Thymine and cytosine are pyrimidines. The nitrogenous bases always pair up in complementary manner which means purine […]

Which bases are present in DNA? Which bases are present in RNA? Which sugars are present in each of these nucleic acids?

Answer: Bases are present in DNA are adenine (A), thymine (T), cytosine (C), and guanine (G). Bases are present in RNA are adenine (A), uracil (U), cytosine (C), and guanine (G). Sugars present in Deoxyribonucleic acid (DNA) are deoxyribose sugar. Sugars present in ribonucleic acid (RNA) are ribose sugar. Explanation: Both Deoxyribonucleic acid (DNA) and […]

Both DNA and RNA are composed of nucleotides. What molecules combine to form nucleotides?

Both Deoxyribonucleic acid (DNA) and ribonucleic acid (RNA) are called as vehicles of genetic inheritance and found in the nuclei of living cells. They are composed of long strand of nucleotides. Nitrogen base, five-carbon sugar and a phosphate group combine to form nucleotides. Nitrogen bases in DNA are adenine, thymine, cytosine, and guanine. Adenine and […]