the control of gene expression

Ectopic pregnancy

When an embryo starts to develop in the fallopian tube and it cannot attach to the uterus lining or the umbilical cord to access the maternal bloodstream and nutrients from the mothers

What is another name for adult cell cloning?

Somatic cell nuclear transfer

What is another name for adult body cells?

Somatic cells

Explain what somatic cell nuclear transfer is

When the nucleus from a somatic cells in implanted into an egg cell

Which is then cloned to produce stem cells which can differentiate into specialised cells

And self renew, by replacing the used up stemcells.

Label the types of stemcells on this hierarchy diagram

Define Totipotent cells

Cells which can mature into any body cell

Define totipotent stem cells

Cells found in the early embryo and can differentiate into any type of cell

Give an example of something made of totipotent cells

Zygotes

Define Pluripotent stem cells

Cells found in embryos and can differentiate into most cells types.

Give to examples of pluripotent stem cells

1. Embryonic stem cells

2. Fetal stem cells

Define Multipotent Stem cells

Cells found in the tissue of adults and can differentiate into limited specialised cells types

Give an example of Multipotent stem cells

Cardiomyocytes- heart muscle cells which can differentiate into heart muscle and tissue

Define Unipotent stem cells

Cells which can only differentiate inti one type of cell

What are the 2 properties of stem cells

Differentiation

Self renewal- keep producing more stem cells which replace the used ones

What does IPS stand for?

Induced Pluripotent Stemcells

How are IPS stem cells made?

When stemcells are taken from a patients uniopotenf cells to grow into specific cells by controlling their gene expression and transcription factors. Allowing them to be genetically altered to gain embryonic stem cell characteristics.

What are three advantages of using IPS

Can create new organs and tissues

No immune rejections after transplant

Better substitute to using human embryos

What are some pros and cons of using embryonic stem cells from embryos

Pros

-could help in fertility treatments

Cons

-ethical and religious issues

-can also be obtained through adult bone marrow not just embryos

Explain how Oestrogen hormone bind t receptors to create transcriptional factors and how they function in the transcription of DNA

1. Oestrogen diffuses across the cell membrane

2. Oestrogen binds to the receptor, forming a transcriptional factor

3. causing a conformational change in the shape of the DNA binding site

4. The transcriptional factor moves through the nuclear pores and binds to the DNA promoter region

5. To drive the transcription of the DNA

Define Chromatin

DNA associated with histones, and is covered in chemicals called tags which form a second layer called an epigenome

Define Epigenetic mechanisms

Environmental factors which can causes heritable changes in gene expression function without changing the base sequence of a DNA-links to Lemarkcism

What Does metastatic mean in metastatic cancer?

Malignant cancer

Explain how cancer is caused (3 marks)

Cancer is caused by damage to the genes that regulate mitosis and the cell cycle.

Leading to uncontrollable cell division

Creating Tumours (groups of abnormal cells)

Either malignant or benign tumours

Explain how the methylation of tumour supressing genes can lead to cancer

Methylation prevents the transcription of gene. Protein is not produced

Therefore no control over cell cycle and mitosis causing cell death/apoptosis

Complete the column for malignant tumours

Complete the column for when the DNA bases are accessible