Cells and control Flashcards
Describe what happens during interphase
During interphase DNA replication occurs and the cell also makes copies of subcellular structures such as mitochondria.
Identify the four stages of mitosis.
Prophase, Metaphase, Anaphase, Telophase.
Explain the difference between a tumour and cancer.
A tumor is a mass of cells that have grown uncontrollably and may cause damage to the body. Cancer is the disease that causes the cells to grow uncontrollably.
Explain what a stem cell is.
A stem cell is an undifferentiated cell that is capable of dividing repeatedly. Embryonic stem cells can produce any other kind of specialized cell. Whereas adult stem cells can only produce the type of cell that is in the tissue around them, such as bone marrow cells can only produce blood cells.
Explain where plant stem cells are found.
Plant stem cells are found in the meristem at the tip of the roots and shoots.
Describe what happens in each stage of mitosis
Prophase - nucleus starts to break down and spindle fibres appear
Metaphase - chromosomes line up along spindle fibres across the middle of the cell
Anaphase - chromosome copies move to either end of the cell on the spindle fibres.
Telophase - new membrane forms around each set of chromosomes which will then form the nuclei
Cytokinesis - new cell membrane forms and plant cells will form cell walls.
Calculate the number of cells produced by mitosis
Mitosis produces two genetically identical, diploid daughter cells.
Explain how percentile charts are used to monitor growth
Percentile growth charts are used to track the growth of babies/children. A child should not vary too much from their percentile line and if they do this can be a sign their rate of growth may need monitoring by a health professional.
Compare growth in plants and animals.
Growth in animals takes place via the number of cells increasing by mitosis. Cell differentiation also happens where stem cells can become specialized cells that are adapted for a specific function.
Growth in plants is different as there are zones called the meristem in the tips of the roots and shoots where undifferentiated cells are produced by mitosis. These cells then undergo elongation where they increase in length and will then differentiate into specialized cells that have different functions.
Explain how stem cells are used in medicine.
Stem cells are used in bone marrow transplants which are used to treat people with diseases of the blood. Adult and embryonic stem cells have also been used in treatments to replace damaged cells such as those in the pancreas of someone who has Type 1 diabetes.
Evaluate the ethics of stem cell use.
Pros of using stem cells - can help to treat illnesses such as cancer, diabetes, Parkinsons. Stem cells either come from willing donors (e.g. bone marrow) or are leftover after IVF treatments (embryonic stem cells ) and would otherwise have been destroyed.
Cons of using stem cells - embryos had the potential to become a new life and now they cannot.
