Cell Cycle and Differentation B2 Flashcards
What is a chromosome?
A chromosome is coiled up DNA which contains genes.
How many chromosomes do humans have?
Eukaryotic cells have 46 chromosomes or 23 pairs of chromosomes (one pair from mother and other pair from father)
Describe the process of mitosis.
The cell duplicates each of its 46 chromosomes and the copied stay attached to it’s original to form an X shape, each arm is the same DNA. Then, all 46 chromosomes line up on the centre of the cell and both arms are pulled to their respective poles by cell fibres. Finally, the cell membrane and cytoplasm pull apart and divide into two daughter cells. Both cells are genetically identical and can contribute to growth, development and repair.
What is cytokinesis?
Cytokinesis is the division that takes place in mitosis when the cell membrane and cytoplasm pulls apart to form 2 daughter cells.
What is the cell cycle?
The cell cycle is where the cells of your body divide so that your body can grow (we need new cells to grow), repair (we need to replace damaged cells) , and develop (we need new cell types as we develop new tissues)
What is cell differentiation?
Cell differentiation is when a cell turns into another type of cell, usually to create specialised cells. In animals this happens in early stages of development.
What is an example of a specialised cell?
A sperm cell has a flagellum so it that can swim to fertilise the egg, it also contains half as much genetic material as a normal cell so that when it meets the egg it will have a normal amount. Finally, it has lots of mitochondria to give it energy to move.
Describe the characteristics of an adult stem cell.
Adult stem cells are usually found in bone marrow. They can only turn into cells from the tissue they originated from. In animals, adult stem cells are usually used to replace damaged/lost cells (e.g. make new skin cells)
Describe the characteristics of an embryonic stem cell.
Embryonic stem cells are found in early human embryos and embryonic stem cells can differentiate into any cell.
Where are plant stem cells found?
Plant stem cells are found in meristematic tissues which is usually in tips of roots and shoots.
Why are stem cells important?
Stem cells are important because they help you grow (we need new cells to grow), repair (we need to replace damaged cells) , and develop (we need new cell types as we develop new tissues)
