Question

There is no DNA in :-

• A. Hair root
• B. An enucleated ovum
• C. Mature RBCs
• D. A mature spermatozoan

Answer 1

The correct option is C Mature RBCs

1) Hair is composed of two distinct structures - Hair follicle and Hair shaft. Hair follicle is the living part located under the skin and Hair shaft is the non-living part that is fully keratinized and is located above the skin surface. The Hair root is present at the base of the Hair follicle and it is the active reproductive portion of the hair follicle. It consists of matrix cells which are nucleated and, thus, it has DNA. 2) An enucleated ovum means an egg cell from which the nucleus is removed, so it will not have nuclear DNA. But a number of mitochondria will remain present in the ovum and, thus, it will have mitochondrial DNA. 3) Erythrocytes or Red Blood Cells (RBCS) carry Oxygen from the lungs to other body tissues. The RBCS contain haemoglobin (an iron containing biomolecule) that can bind Oxygen. Red colour of RBCs and of blood is due to that of haemoglobin In mammals, the mature RBCs are biconcave disc shaped cells that lack nuclei, ribosomes and other cytoplasmic organelles such as mitochondria. Thus, they neither have nuclear DNA nor mitochondrial DNA. 4) Spermatozoa or sperm cell is the male reproductive cell. it is motile. Structure of a typical mature spermatozoan consists of a head and a tail A compact nucleus is present in the head. Thus, DNA is present in the mature spermatozoa.
So, the correct option is option C.