IQ2) Why are you the same yet different to your parents?
2.6) Meiosis and the transmission of inheritable characteristics
Discussion
1) Why do we look like are parents, grandparents, sisters, brothers, cousins etc but different?
2) Why don't we look the same as our mum?
1) Why do we look like are parents, grandparents, sisters, brothers, cousins etc but different?
2) Why don't we look the same as our mum?
There are three main factors that affect how you look
1) Inherited Genes from your parents 2) Environment conditions that you live in 3) And the Unknown Factor - scientists cannot entirely determine why you look the way you do. It could have to do with special viruses called "Retroviruses" that turn genes on and off. |
An inherited trait is a feature or characteristic of an organism that has been passed on to it through its genes. This transmission of parental traits to their offspring always follows certain principles or laws. The study of how inherited traits are passed on is called genetics. Some common inheritable traits (or characteristics) are tongue rolling, widow's peak, longer second toe, right handed, freckles and others.
Activity) Take home the handout and fill it out for yourself, mum, dad and any siblings that you have. Then bring it back to school
Activity) Take home the handout and fill it out for yourself, mum, dad and any siblings that you have. Then bring it back to school
Now that you understand about inherited characteristics and sexual reproduction, we are going to learnt about how the sex cells or gametes are formed.
Notes and Activities - Human cells contain 2 pairs of 23 chromosomes, or 46 chromosomes in total. 23 of these come from our father and 23 from our mother. Sex cells, or gametes are known as ova (eggs) and spermatozoa (sperm). These are produced using a special type of cell division known as meiosis in order to produce cells with half the normal number of chromosomes (i.e. one copy of each chromosome, or 23 chromosomes in total). 1. Discussion: Why do gametes need to contain half the normal number of chromosomes? 2. Watch the YouTube video "Meiosis" by the Amoeba Sisters to the right and make notes in your exercise books. You do not need to know about interphase, prophase, or PMAT - just get the general gist about what is happening. HOWEVER LISTEN CAREFULLY ABOUT CROSSOVER 3. Complete the Meiosis Worksheet. You can use the second youtube video below "Mitosis and Meiosis Simulation" but start watching from the 6 minute mark. The answers are on google classroom Make sure you have FIVE sections to your meiosis diagram i) Parent Cell ii) Chromosomes double iii) First Cell Division iv) Chromosomes divide v) Second Cell Division 4. Complete worksheet 3.1) Cell Division - Meiosis. Again if you have trouble the answers are on google classroom |
The 46 Human Chromosomes
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Additional Videos if interested
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Extension Information
1) Meiosis on the CK-12 Website
2) Animation of Animal Cell Meiosis on Cellsalive
1) Meiosis on the CK-12 Website
2) Animation of Animal Cell Meiosis on Cellsalive
2.7) What is DNA and How does it build an organism?
2.8) Genetic Mutations
Examples of Genetic Mutations
Genetic Testing for Inheritable Diseases and Cancers
Angelina Jolie uses DNA testing
Watch the video on Angelina Jolie's Mastectomy and identify the technology that was used to help Angelina to make her decision. Explain how advances in scientific technologies have improved our quality of life. In 2015, Angelina Jolie had her ovaries and fallopian tubes removed after blood tests showed that she had raised ovarian cancer markers. Read the article about her decision and operation "Angelina Jolie removes her female organs after cancer scare". |
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A predisposition to certain cancers can be inherited via altered genes. Genetic testing aims to detect a genetic alteration that might increase the chances of a person developing a particular cancer. This testing is available to some families with a high risk of a genetic predisposition to certain cancers including breast cancer, ovarian cancer and bowel cancer.
Genes control the growth, division and life span of every cell in the body. Your genes come in pairs – one inherited from your mother and the other from your father. Some people inherit altered genes that may predispose them to developing particular cancers. For example, a woman who has inherited a single altered copy of one of the specific breast cancer genes (known as BRCA1 and BRCA2) has a higher risk of breast and ovarian cancer than a woman who inherited two normal copies of both genes. However, only around five out of every hundred cases of breast cancer may be due to an inherited genetic predisposition. Genetic testing is available to a small number of families at the highest risk of having an inherited predisposition to cancer. Generally, it is necessary to test a person who has had cancer first to identify the genetic change causing cancer in the family. If a genetic change is found, it confirms that the cancers in that family are due to an inherited predisposition to cancer. Blood relatives who have no signs of cancer can then choose to have testing to find out if they have inherited the altered gene that has been identified and could increase their risk of developing specific types of cancer. If they have inherited a predisposition to cancer, the Familial Cancer Centre will develop a personal program designed to manage their risk. 1. 7 Diseases that you can learn from a DNA test 2. Wear Your Genes - Scarves turn your DNA into a unique pattern 3. Take an online DNA test and you could be revealing far more than you realise |