Question

2. If the two genes are unlinked, an organism with the genotype of AaBb can produce gametes containing

1. either Aa or Bb.
2. AB, Ab, aB, or ab.
3. AaBb.
4. AB or ab.
5. none of the abov

3. Which of the following is NOT correct about miRNA?

1. It is involved with posttranscriptional regulation in eukaryotes.
2. It leads to one type of RNA interference.
3. Its name is derived from “mitochondrial RNA.”
4. It binds to a complementary mRNA sequence.
5. It is found in many different organisms, and can silence gene expression.

4. A densely staining region of highly compacted chromatin is known as ________ and is generally________.

1. heterochromatin; not transcribed
2. homochromatin; not transcribed
3. histone-dependent chromatin; transcribed
4. primary chromatin; transcribed
5. euchromatin; not transcribed

5. Which of the following is TRUE about DNA methylation?

1. Genes are silenced through methylation of all four bases.
2. It is a method of translational regulation.
3. It can silence large groups of genes.
4. It is common in most prokaryotes.
5. It leads to genomic imprinting, which is reversibl

6. Retroviruses make ________ by the process of ________.

1. RNA copies of DNA; reverse transcription
2. DNA copies of RNA; reverse transcription
3. genetic probes; Southern blotting
4. genetic probes; Northern blotting
5. telomerase; mutagenesis

Answer 1

Answer) AB, Ab, aB and ab.

______

Explanation: The genotype is AaBb. When the genes are unliked, then there are not found crossing over between two genes. The number of gametes= {2}^n = (2)^2 = 4

Here n is the number of heterozygous genes. There are two genes i.e. A and B.

Number of gametes are: AB, Ab, aB and ab.

____________________________________________________________________

Answer] 'c' is the answer.

miRNA stands for micro RNA. This is an inhibitory mRNA. It binds to the complementary sequence in target mRNA. This leads to silence the mRNA. This is the case of post transcriptional regulation.

____________________________________________________________________

Answer} a is the answer.

The heterochromatin is the tightky packed region. The transcription factor can not interact with promoter. That's why the transcription is not found. ( heterochromatin,not transcribed)

___________________________________________________________________

Answer} e is the answer.

Methylation occurs on the Adenine and Cytosine nitrogenous bases. Hence there are not found methylation on all four bases.

It is a transcriptional mode of regulation.

It leads to slience the gene in the region of methylation. It leads to imprint the genes.

__________________________

___________________________

Answer) b is the answer.

Retroviruses have reverse transcriptase enzyme. It leads to synthesise RNA from DNA.