NEET BIOLOGY

Detailed explanation-1: -Unlike most other eukaryotic cells, mature red blood cells don’t have nuclei. When they enter the bloodstream for the first time, they eject their nuclei and organelles, so they can carry more hemoglobin, and thus, more oxygen. Each red blood cell has a life span of around 100–120 days.

Detailed explanation-2: -While immature red blood cells contain a nucleus, mature human red blood cells do not.

Detailed explanation-3: -Mammal red blood cells (erythrocytes) contain neither nucleus nor mitochondria. Traditional theory suggests that the presence of a nucleus would prevent big nucleated erythrocytes to squeeze through these small capillaries. However, nucleus is too small to hinder erythrocyte deformation.

Detailed explanation-4: -Red Blood Cells are produced in the bone marrow and they have a nucleus when they are initially produced. Later, they lose nucleus in order to accommodate more haemoglobin so that they can transport more amount of oxygen.

Detailed explanation-5: -Prokaryotes are organisms whose cells lack a nucleus and other organelles. Prokaryotes are divided into two distinct groups: the bacteria and the archaea, which scientists believe have unique evolutionary lineages. Most prokaryotes are small, single-celled organisms that have a relatively simple structure.