How many nucleotides are found in the genome of Bacteriophage Phi X 174?
Bacteriophage Phi X 174 contains exactly 5386 nucleotides. This is a specific data point used to illustrate genome sizes.
Question 142 of 668
📘 CLASS XII
What is the number of base pairs in Bacteriophage Lambda?
Bacteriophage Lambda has a genome size of 48,502 base pairs. The calculation trick 50 - 2 = 48 can help remember this number.
Question 143 of 668
📘 CLASS XII
Which amino acids are histones primarily composed of?
Histones are basic proteins rich in the basic amino acids Lysine and Arginine. These positive residues allow them to bind tightly to negative DNA.
Question 144 of 668
📘 CLASS XII
Why is DNA negatively charged?
DNA is negatively charged and acidic primarily due to the presence of phosphate groups in its backbone, which release protons at physiological pH.
Question 145 of 668
📘 CLASS XII
The structure formed by the wrapping of DNA around a histone octamer is called?
The complex of negatively charged DNA wrapped around the positively charged histone octamer is called a nucleosome.
Question 146 of 668
📘 CLASS XII
Which histone is NOT part of the nucleosome core octamer?
The nucleosome core is an octamer made of H2A, H2B, H3, and H4 (two of each). H1 is the linker histone that seals the DNA as it enters and exits the nucleosome.
Question 147 of 668
📘 CLASS XII
Approximately how many base pairs of DNA wrap around a histone octamer?
While the core DNA is about 146 bp, the entire nucleosome structure including the linker DNA associated with it is typically cited as containing about 200 base pairs of DNA.
Question 148 of 668
📘 CLASS XII
Which chromatin type is transcriptionally active?
Euchromatin is the loosely packed, light-staining form of chromatin that allows transcription machinery access to DNA, making it transcriptionally active.
Question 149 of 668
📘 CLASS XII
Heterochromatin is characterized by being?
Heterochromatin is densely packed and stains darkly. Due to this tight packaging, it is inaccessible to transcription enzymes and is therefore transcriptionally inactive.
Question 150 of 668
📘 CLASS XII
Which region of the chromosome is likely to contain Heterochromatin?
Heterochromatin is typically found at the centromeres and telomeres of chromosomes, providing structural stability but not coding for active proteins.
