Unit1_part5 Flashcards
What is the result of mitosis?
Mitosis produces 2 identical daughter cells
What is the ploidy of daughter cells after mitosis if the parental cell has a ploidy of 2n=4?
2n=4, the daughter cells have the same ploidy as their parental cells
Give and explain two situations where mitosis is involved.
- Growth: It helps growth because it allows for cells to be replicated. Thus, mitosis adds cells to make one grow.
- Replacement of worn-out or damaged cells: Mitosis allows the production of new cells that can replace the cells that are damaged or worn out.
Explain the process (steps) involved in mitosis.
- Dna is replicated
- Separation of sister chromatids
- 2 diploid cells are produced and they are identical to the parental cell
Are the cells produced from mitosis diploid or haploid?
The cells produced from mitosis are diploid cells because they are identical to the parental cell which is a diploid cell.
What are the main differences between meiosis and mitosis?
- In meiosis there is crossing-over. In fact, alleles are exchanged meaning that there is genetic recombination. In mitosis, there is no exchange in terms of alleles, or sections of DNA. There is no creation of new combinations of alleles.
- Meiosis produces 4 haploid cells that are unique (genetically different) whereas mitosis produces 2 diploid cells that are identical to the parental cell.
- In meiosis, there is a change in ploidy. On the other hand, there is no change in ploidy in mitosis.
Name the hormones involved in embryo development and growth and where they are secreted/produced.
- GHRH (growth hormone-releasing hormone) is produced in the hypothalamus
- GH (growth hormone) is produced and secreted in the anterior pituitary
- IGF (insulin-like growth factor) is produced in the liver
Explain the hormonal cascade involved with growth.
- GHRH produced by the hypothalamus
- GHRH will activate the production of GH in the anterior pituitary
- GH will affect many tissues in the body to grow.
- It will activate specific cells in the liver
- These cells will produce IGH that will contribute to growth
What can happen if there are abnormal levels of GH or GHRH?
Pathologies like gigantism and pituitary dwarfism are caused by abnormal levels of GH or GHRH.
What can cause pituitary dwarfism?
- Pituitary dwarfism can be caused by problems with the hypothalamus. In fact, if the hypothalamus is not producing enough GHRH, it will not activate, or not activate enough the anterior pituitary. This means that there will be very low levels of GH.
- Pituitary dwarfism can also be caused by problems with the anterior pituitary. In fact, if the anterior pituitary is not working properly and is not responding to GHRH, even if there are normal levels of GHRH, the anterior pituitary will not produce enough GH.
In both these cases, growth will not occur because of low levels of GH.
What can cause gigantism?
- Gigantism can happen if the hypothalamus cannot stop producing GHRH. This means that the anterior pituitary will constantly be activated to produce GH.
- Gigantism can also be caused by problems with the anterior pituitary. In fact, in that case, the pituitary cannot stop producing GH.
In both these cases, increased growth will happen because of high levels of GH.
How are telomeres helping your body stay healthy?
They make sure you stay healthy because when telomeres become too short, the cell will die. This process ensures that your cells do not replicate if there is an error while your DNA is replicated. Moreover, some proteins can add letters to telomeres to make them last longer.
What are telomeres?
Telomeres protect coding regions (genes) at the end of each chromosome. They act as buffers.
What happens to telomeres when DNA is replicated?
Telomeres become shorter every time cells divide (DNA is replicated).
Name the four advantages or cancer cells.
- They have an increased and uncontrolled cell cycle.
- They do not undergo programmed cell death.
- They can spread to other regions of the body.
- They can cause the growth of new blood vessels.
