Which of the following statements regarding human antibodies is/are accurate? 1. IgG constitutes the largest proportion of antibodies in human blood. 2. IgE plays a key role in allergic responses. 3. IgA is primarily located in bodily secretions such as saliva and breast milk.
1, 2 and 3 all are correct
Statement 1 ✓ — IgG is the most abundant antibody in human serum, constituting about 75–80% of total serum immunoglobulins.
Statement 2 ✓ — IgE binds to mast cells and basophils and triggers allergic responses (e.g., hay fever, asthma) upon antigen exposure.
Statement 3 ✓ — Secretory IgA (sIgA) is the predominant antibody in mucosal secretions including saliva, tears, intestinal fluid, and breast milk.
All three statements are correct. Hence Option D is correct.
Identify the animal that does NOT have bilateral symmetry.
Which of the following statements is FALSE?
What happens to the guard cells when water flows into them?
Colloidal systems – such as gum, starch, proteins, cellulose, agar, and gelatine – when placed in water, will absorb a large volume of water and swell up. These substances are called _________.
_______ is a branch of biology that studies fungi.
Which of the following is a natural flame retardant?
Which component performs the task of capturing oxygen in the blood?
Select the correct option about Kwashiorkor.
Statement A: It is a form of malnutrition caused by a lack of fat in the diet.
Statement B: Children who develop Kwashiorkor may not grow or develop properly and may remain stunted for the rest of their lives.
Match the columns.
Column-A (Enzyme/Protein) | Column-B (Role in DNA replication) | ||
i. | Helicase | a. | Joins the 3' end of the new DNA fragment to the 5' end of the previous one |
ii. | RNA primase | b. | Nucleotide polymerisation |
iii. | DNA polymerase | c. | RNA primer synthesis |
iv. | DNA ligase | d. | Opens up the DNA double helix |
Which cells, also called neurilemma cells, are the main glial cells in the PNS and play an essential role in the survival and functions of neurons?
Which of the following statements about living and non-living being is/are correct?
1. While living being can demonstrate growth and repair, non-living being cannot.
2. While living being demonstrates metabolic processes, non-living being does not.
Movement of materials to different parts of cytoplasm and nucleus is generally carried out by
Which one of the following cell organelles may play a role in expelling excess water and wastes in case of unicellular organisms?
Transformation of meristematic cells into specific permanent tissues occurs by the process of
If human blood is placed in a 2% detergent solution, what will happen to the RBC?