Cell Division 7 th Grade Science Chapter 3 – Section 5

Cell Division and Growth A single cell _______ and then _______, forming two new cells. A single cell grows and divides producing ____ new cells. Then the two cells grow and divide forming ____and so on. The process of cell growth and division is _________ and it happens in __________.

Cell Division and the Cell Cycle __________ - sequence of growth and division – a cell grows, prepares for division, and divides into 2 new cells. -The two new cells are called _____________. -Each daughter cell begins the ___________ again. Three stages in the cell cycle: 1. _________ - cell grows 2. __________ - cell divides 3. __________ - two new cells are formed

Stage 1. Interphase During _________, the cell grows, makes a copy of its DNA, and prepares to divide into two new cells. – During the first part of interphase, the cell _______ to its full size and produces structures that it needs – The next part of interphase, the cell makes an exact copy of its _____ in its nucleus. This process is called ______________. – The cell prepares itself for _________

Stage 2 - Mitosis __________ - one copy of the DNA is distributed to each of the two new daughter cells. There are four phases in the process of mitosis 1. ________ 2. _________ 3. _________ 4. __________

Prophase, Metaphase, Anaphase Prophase - Chromatin in the ________ condense to form ___________. The thread-like chromatin move to opposite sides of the nucleus. The _______________ breaks down. Metaphase – The __________ line up across the center of the cell. Anaphase – The chromosomes separate and each ________ becomes a new chromosome. The new chromosomes move to opposite ends of the cell. The cell stretches out – ends are pulled apart.

Telophase During _________ a new ____________ forms around each new group of chromosomes. Stage 3 – Cytokinesis ______________ - the cytoplasm divides and the organelles are distributed to each of the two new cells. Cytokinesis begins during _________.

Cytokinesis The __________ pinches into two new cells. Each daughter cell gets about half of the ____________. Each daughter cell has the same number of ____________as the parent cells At the end of cytokinesis, ___________ begins again.

Structure and Replication of DNA ______________ - ensures that each daughter cell will have the genetic information it needs to carry out its activities. Structure of DNA – twisted ladder, _________ Each rung of the ladder is made up of _____________. There are four different bases - ____________, _____________, ____________, and ____________

DNA Replication _____________ begins when the two sides of the DNA strand ______and separate. The molecules of DNA separates between the two ___________________. Nitrogen bases that are floating in the ________ pair up with bases on each half of the DNA molecule. Adenine pairs with Thymine, Guanine pairs with cytosine.