The scientist who proposed the 'one gene-one enzyme' hypothesis using Neurospora crassa was: MCQ with Answer and Explanation

The scientist who proposed the 'one gene-one enzyme' hypothesis using Neurospora crassa was:
A. Morgan
B. Watson and Crick
C. Beadle and Tatum
D. Mendel
Answer: Option C
Solution (By JKExamLibrary)
George Beadle and Edward Tatum irradiated Neurospora crassa and showed that mutations in specific genes caused defects in specific enzymes, leading to the one gene-one enzyme concept. Watson and Crick discovered DNA structure, Mendel laws of inheritance, Morgan chromosome theory.

Discuss this Question (0)

No comments yet. Be the first to start the discussion!

Practice More Biology Questions

Question #1
In human nutrition, the 'Glycemic Index' (GI) of a food measures:
A. The caloric value of the food
B. The rate at which the food raises blood glucose levels after consumption
C. The total carbohydrate content per 100 grams
D. The amount of dietary fiber present in the food

Correct Answer: Option B


Explanation:
The Glycemic Index (GI) is a numerical scale (from 0 to 100) that measures how quickly a carbohydrate-containing food raises blood glucose levels compared to a reference food (usually pure glucose or white bread). Foods with a high GI (like white bread, sugary drinks) cause a rapid spike in blood sugar, while low GI foods (like whole grains, legumes) cause a slower, more gradual rise. It does not measure total carbohydrate amount.

This question belongs to: Science Biology
Question #2
Assertion (A): Double circulation is seen in birds and mammals.
Reason (R): It ensures complete separation of oxygenated and deoxygenated blood.
A. A false, R true.
B. Both A and R are true, and R is the correct explanation.
C. Both A and R are true, but R is not the correct explanation.
D. A true, R false.

Correct Answer: Option B


Explanation:
Double circulation (pulmonary and systemic) with a four-chambered heart keeps oxygenated and deoxygenated blood separate, increasing efficiency. R correctly explains A.

This question belongs to: Science Biology
Question #3
The enzyme in saliva that begins starch digestion is:
A. Lipase
B. Amylase
C. Pepsin
D. Trypsin

Correct Answer: Option B


Explanation:
Salivary amylase (ptyalin) hydrolyzes starch into maltose and dextrins in the mouth. It functions optimally at neutral to slightly alkaline pH. Pepsin digests proteins in the stomach, lipase digests fats, trypsin is a pancreatic protease. Salivary amylase action ceases in the acidic stomach.

This question belongs to: Science Biology