CBSE 11TH BIOLOGY - Online Test
Q1. Calvin cycle is discovered by
Answer : Option C
Explaination / Solution:
The work of Melvin Calvin is the discovery, the first CO2 fixation product was a 3-carbon organic acid. He also contributed to working out the complete biosynthetic pathway; hence it was called Calvin cycle.
Q2.
Read the following statements :
i. Pressure contributed by and individual gas in a mixture of gases is called its partial pressure
ii. in alveolar air is 45 mm Hg and in venous blood is 40 mm Hg.
Answer : Option A
Explaination / Solution:
- In a mixture of gases, each gas has a partial pressure which is the hypothetical pressure of that gas if it alone occupied the entire volume of the original mixture at the same temperature. The total pressure of an ideal gas mixture is the sum of the partial pressures of each individual gas in the mixture.
- The in alveolar air is 40 mm Hg and in venous blood is 45 mm Hg.
Q3.
Match the names of organ having isolated endocrine cells with hormone secreted by those cells :
| Organ | Hormone |
| a) Kidney | i) angiotensin |
| b) Liver | ii) Erythropoietin |
| c) Gastro-intestinal Tract | iii) ANF |
| d) Heart | iv) CCK |
Answer : Option C
Explaination / Solution:
The atrial wall of our heart secretes a very important peptide hormone called ANF.
Angiotensin I is produced by the action of renin (an enzyme produced by the kidneys) on a protein called angiotensinogen, which is formed by the liver.
The juxtaglomerular cells of kidney produce a peptide hormone called erythropoietin.
The gastro-intestinal tract secrete peptide hormone called CCK.
Q4. Petromyzon is included under
Answer : Option D
Explaination / Solution:
Petromyzon is a jawless vertebrate and hence included under Agnatha.
Q5. Chitin occurs in cell wall of
Answer : Option C
Explaination / Solution:
The cell wall of fungi is made of chitin,complex sugar molecules. The cell wall of plants are made up of cellulose.
Q6. Read the following :
i. The instrument used for recording heart’s electrical events is named electrocardiogram.
ii. In any ECG the part of base line between any two deflections is called interval.
iii. Abnormality in the working of heart changes wave pattern of ECG.
i. The instrument used for recording heart’s electrical events is named electrocardiogram.
ii. In any ECG the part of base line between any two deflections is called interval.
iii. Abnormality in the working of heart changes wave pattern of ECG.
Answer : Option B
Explaination / Solution:
ECG is a graphical representation of the electrical activity of the heart during a cardiac cycle.
Q7. In eukaryotic organisms aerobic respiration takes place in presence of
Answer : Option C
Explaination / Solution:
Aerobic means “with air”. This type of respiration needs oxygen for it to occur so it is called aerobic respiration.
The word equation for aerobic respiration is:
Glucose + Oxygen Carbon dioxide + Water + Energy
The chemical equation is:
C6H12O6 + 6O2 6CO2 + 6H2O + 2900 kJ/mol
Q8. Inflorescence which shows indefinite growth and bears a number of flowers due to active growing point is called
Answer : Option D
Explaination / Solution:
In recemose inflorescence indefinite growth occurs and bears a number of flowers due to active growing point.
Q9. Division of nucleus without being followed by cytokinesis results into
Answer : Option A
Explaination / Solution:
The division of nucleus or karyokinesis without being followed by cytokinesis results into increase in the content of nucleus, a condition known as multinucleate condition.
Q10.
Counter current mechanism :
i. It operates in all vertebrates.
ii. It produces hypertonic urine.
Answer : Option D
Explaination / Solution:
Counter current mechanism operates in mammals but not in all vertebrates. Due to counter current mechanism it produces hypertonic urine, highly concentrated.
