The genetic code is read in triplets of nucleotides called:
A. Exons
B. Codons
C. Anticodons
D. Introns
Answer: Option B
Solution (By JKSSB Mock Tests)
The genetic code is a sequence of nucleotide triplets in mRNA called codons. Each codon consists of three consecutive nitrogenous bases and specifies a particular amino acid or a stop signal during protein synthesis. For example, AUG is the start codon (methionine). Anticodons are the complementary triplets found on tRNA molecules.
Explanation:
Selman Waksman and his team isolated streptomycin from the soil bacterium Streptomyces griseus in 1943. It was the first effective antibiotic against tuberculosis. Fleming discovered penicillin, Pasteur developed rabies vaccine, Koch identified tuberculosis bacillus. Waksman coined the term 'antibiotic'.
Consider the following statements about the circulatory system:
1. Arteries carry blood away from the heart.
2. Veins have valves to prevent backflow.
3. Capillaries are thick-walled vessels.
Which of the above is/are correct?
Explanation:
Arteries carry blood from the heart; veins have valves; capillaries are thin-walled for exchange. Statement 3 is false. So 1 and 2 are correct.
Explanation:
Invertase (sucrase) hydrolyzes sucrose into its constituent monosaccharides, glucose and fructose. Maltase acts on maltose, lactase on lactose, amylase on starch. Invertase is found in the intestinal brush border and is also produced by yeast. The resulting mixture is called invert sugar, sweeter than sucrose.
No comments yet. Be the first to start the discussion!