In genetics, the 'Spliceosome' is a large, complex molecular machine found within the nucleus of eukaryotic cells. Its primary function is to: MCQ with Answer and Explanation

In genetics, the 'Spliceosome' is a large, complex molecular machine found within the nucleus of eukaryotic cells. Its primary function is to:
A. Translate mRNA into protein
B. Remove introns from pre-mRNA and join the exons together to form mature mRNA
C. Add the 5' cap and poly-A tail to mRNA
D. Synthesize mRNA from a DNA template
Answer: Option B
Solution (By JKSSB Mock Tests)
The spliceosome is a large, dynamic complex composed of five small nuclear ribonucleoproteins (snRNPs, pronounced 'snurps') and numerous other protein factors. It assembles on the pre-mRNA transcript in the nucleus. Its primary function is to catalyze the splicing of pre-mRNA: it precisely recognizes the splice sites at the boundaries of introns and exons, removes the non-coding intron sequences, and ligates (joins) the coding exons together to form a continuous, mature mRNA molecule that can be exported to the cytoplasm for translation.

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Practice More Biology Questions

Question #1
The 'Hormone Amylin' (Islet Amyloid Polypeptide) is co-secreted with insulin by the beta cells of the pancreas. Its primary functions include:
A. Increasing gastric acid secretion
B. Stimulating insulin release
C. Stimulating intestinal motility
D. Slowing gastric emptying, suppressing glucagon secretion, and promoting satiety

Correct Answer: Option D


Explanation:
Amylin, also known as Islet Amyloid Polypeptide (IAPP), is a 37-amino acid peptide hormone that is co-secreted with insulin from the pancreatic beta cells in response to meals (in a ratio of about 1:100 to insulin). Its primary functions are to complement the actions of insulin in regulating postprandial (after-meal) glucose levels. It does this by slowing gastric emptying (preventing a rapid spike in blood glucose), suppressing the secretion of glucagon (preventing the liver from releasing glucose), and acting on the brain to promote satiety and reduce food intake.

This question belongs to: Science Biology
Question #2
The organism that causes citrus canker is:
A. Virus
B. Mycoplasma
C. Bacterium
D. Fungus

Correct Answer: Option C


Explanation:
Citrus canker is a bacterial disease caused by Xanthomonas citri (syn. X. axonopodis pv. citri). It produces raised necrotic lesions on leaves, fruit, and stems, causing defoliation and reduced yield. It spreads via rain splash and contaminated tools. No viral or fungal causal agent.

This question belongs to: Science Biology
Question #3
Identify the INCORRECT statement about the human body:
A. The skin is the largest organ.
B. The femur is the longest bone.
C. The liver is the largest gland.
D. The heart is located on the right side of the chest.

Correct Answer: Option D


Explanation:
The heart is situated in the mediastinum slightly left of the midline. All other statements are true.

This question belongs to: Science Biology