B2 Flashcards
What is a chromosome?
A chromosome is in the nucleus, and it carries the genes that contain the instructions for making both new cells and all the tissues and organs.
What is a gene?
A gene is a small packet of information that controls a characteristic, or part of a characteristic of your body.
What is DNA
It is the unique molecule that makes up your chromosomes.
How many chromosomes do you have?
You have 46- arranged in 23 pairs. In each pair of chromosomes, one chromosome is inherited from your father and one your mother. Every cell apart from your sex cells(gametes) have 46 but gametes have only 23.
What does cell division give you?
It gives you two identical cells.
What is the cell cycle?
Stage 1:The longest stage, where the cells grow bigger, increase their mass and do normal activities. They replicate their DNA to form two copies of the chromosomes.
Stage 2:Mitosis
Stage 3:The cytoplasm and cell membranes also divide to form two identical cells.
What is mitosis?
The process where one set of chromosomes are pulled to each end of the dividing cell and the nucleus divides.
What is a stem cell?
An undifferentiated cell, which can become any type of needed cell.
What is a specialised cell?
A specialised cell is a cell that has been differentiated in order to carry out a specific function, by changing its sub cellular structure.
What is different about stem cells?
Most cells can divide by mitosis but stay as the same type of cell. However some differentiated cells can not divide at all so adult stem cells replace dead or damaged cells.
How is differentiation different in plant cells?
Most plant cells are able to differentiate all through their lives. Undifferentiated cells are made at active regions of the stem and roots known as meristems, where mitosis takes place almost continually.
What is a meristem?
Meristems are regions of unspecialised cells in plants that are capable of cell division. Meristems make unspecialised cells that have the potential to become any type of specialised cell. They are only found is certain parts of the plant such as the tip of roots and shoots and in between the xylem and phloem.
What do the egg and sperm fuse together to form and what happens to that?
They form a zygote, which divides and becomes a hollow ball of cells known as the embryos. The cells in this ball are called embryotic stem cells that differentiate to form all specialised cells in your body.
Where can stem cells be taken from?
Adult stem cells can be taken from an adults bone marrow, which can be used to make blood cells, and a baby embryo, which can be used for any cell, however it can have issues for the ethics.
What can stem cells treat in humans?
They can treat spinal cord injuries, diabetes, the heart after damage in a heart attack, eyesight in the blind and damaged bone and cartilage.
