Answer:
Haemoglobin is a protein present in red blood cells, responsible for transporting oxygen from the lungs to cells in the body. Haemoglobin gives red blood cells their distinctive colour. Haemoglobin levels differ between individuals, but men usually have higher haemoglobin levels than women.
When the classrooms are divided into ability levels, type of preparation or according to future plans, it is called tracking. Tracking is a system where in, the school's population is divided and assigned to their respective capabilities or their achievements.
There is no answers to check so I need answers pls