CBSE 11TH BIOLOGY - Online Test
Q1. Solarisation is
Answer : Option A
Explaination / Solution:
Solarisation is the inhibition of photosynthesis at very high light intensities due to photoxidation of certain compounds and destruction of chlorophyll moleucules.
Q2. Ram suffers punctures in his chest cavity without any damage to the lungs in an accident. It results in
Answer : Option D
Explaination / Solution:
haemopneumothorax, is a medical term describing the combination of two conditions: pneumothorax, or air in the chest cavity, and hemothorax (also called hæmothorax), or blood in the chest cavity. A hemothorax, pneumothorax or both can occur if the chest wall is punctured.
Becauseof punctured chest wall, the lungs cannot expand, the pressure in the lungs never drops and no air is pulled into the bronchi. Respiration is not possible.
Q3. Animals of class Mammalia have
Answer : Option C
Explaination / Solution:
The animals of class Mammalia have seven cervical vertebra and four chambered heart. Mammalian are charecterised by presence of mammary gland to feed their young ones.
Q4. Metal ions required for functioning of enzyme is
Answer : Option D
Explaination / Solution:
A number of enzymes require metal ions for their activity which form coordination bonds with side chains at the active site and at the same time form one or more cordination bonds with the substrate, e.g., zinc is a cofactor for the proteolytic enzyme carboxypeptidase.
Q5. Among mammals, nucleus is absent in :
Answer : Option B
Explaination / Solution:
The absence of a nucleus is an adaptation of the red blood cell for its role. It allows the red blood cell to contain more hemoglobin and, therefore, carry more oxygen molecules.Platelets are devoid of nucleus in most of the mammals.
Q6. The complete combustion of glucose produces
Answer : Option C
Explaination / Solution:
The complete combustion of glucose, which produces carbon dioxide and water as end products, yields energy most of which is given out as heat.
Q7. Potato is a modified
Answer : Option C
Explaination / Solution:
Potato is a modified stem as it contain nodes in form of eyes on potato tubers which germinate to produce new potato plants if placed in suitable conditions.
Q8. In animal cells, during G2 phase
Answer : Option B
Explaination / Solution:
During the G2 phase, proteins and RNA are synthesised in preparation for mitosis while cell growth continues.
Q9. Adult human kidney is metanephric. So, first embryonic tubules formed in vertebrates during embryonic development are :
Answer : Option C
Explaination / Solution:
adult human kidney is metanephric, the third and final excretory organ that develops in a vertebrate embryo. First embryonic tubules formed in vertebrates during embryonic development are pronephric.
Q10. A group of cells having a common origin and usually performinga common function is
Answer : Option C
Explaination / Solution:
A tissue is an ensemble of similar cells from the same origin that together carry out a specific function. Organs are then formed by the functional grouping together of multiple tissues.
