Which of the following cells do not contain nucleus? 1. Root hair cells 2. Red blood cells 3. Platelets 4. Monocytes Select the correct answer using the code given below.

In humans and other mammals, mature red blood cells (erythrocytes) lack a nucleus to maximize space for hemoglobin, which facilitates efficient oxygen transport [5]. Platelets, which are cytoplasmic fragments derived from megakaryocytes, also do not contain a nucleus. In contrast, root hair cells are specialized plant cells that contain a nucleus to regulate growth and metabolic activities. Monocytes are a type of white blood cell (leukocyte) characterized by a large, often U-shaped or horseshoe-shaped nucleus [5]. While prokaryotes like bacteria lack a well-defined nucleus, they possess a nucleoid [2]. Therefore, among the options provided, only red blood cells and platelets are anucleate in their mature functional state in humans. Monocytes and root hair cells are nucleated cells essential for immune response and nutrient absorption, respectively.

Sources

1. [3] https://www.sciencedirect.com/topics/agricultural-and-biological-sciences/blood-cell
2. [4] Science ,Class VIII . NCERT(Revised ed 2025) > Chapter 2: The Invisible Living World: Beyond Our Naked Eye > Activity 2.3: Let us investigate > p. 13
3. [5] https://oertx.highered.texas.gov/courseware/lesson/1818/student/?section=10
4. [1] https://www.ncbi.nlm.nih.gov/books/NBK2263/
5. [2] https://en.wikipedia.org/wiki/Red_blood_cell