<

Biology Form 5 Science

Chapter 2 : CELL DIVISION

TYPES OF CELL DIVISION

There are two types of cell division

  • Mitosis or mitotic cell division
  • Meosis or meotic cell division

 

MITOSIS CELL DIVISION

During mitosis, the daughter cells finish up containing exactly the same number of chromosomes as a parent cell. This type of cell division take place during an organism growth. In growing organism mitotic cell division is continuously taking place. It place a very important role in growth, cell representation and asexual reproduction. The resting place between one division on the other is called the interphase, mitosis has been divided into four distinct stages

  • Prophase
  • Metaphase
  • Anaphase
  • Telophase

 

  1. PROPHASE:  At this stage the thread coil become shorter and fater in a process called condensation. Finally  each chromosomes divide inti txo identical copies od chromosome called chromatid
  2. METAPHASE: At early metaphase the chromosmes are arranged at the equator of the spidle with the chromatid of each chromosomes oriented toward opposite poles. The chromosomes are attached to the spindle fibres by their centrotes. The centrometer then divided and begin to move apart in opposite direction toward the poles of the spindle.
  3. ANAPHASE: During anaphase the chromatid are pulled toward opposite poles of the spindle by the shortening of the spindle fibre. The centromere divide into two, this separate the sister chromatid in each chromosome
  4. TELOPHASE: the chromatid, now new chromosome which the pole and the spindle fibres disappears, a nuclei membrane is reformed. The chromosome uncoil and assume their original thread like form mitosis is now complete. 

DIFFERENCES BETWEEN MEIOSIS AND MITOSIS

par Claude Foumtum