Unit 3 & 4: Genetics Unit 3: Unit 4: Macro - Genetics Micro - Genetics What we can see What we cannot see such as our such as DNA physical features

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1 Unit 3 & 4: Genetics Unit 3: Macro - Genetics What we can see such as our physical features Unit 4: Micro - Genetics What we cannot see such as DNA

2 Unit 3:Macro genetics Genetics that we can see Liger?

3 Unit3:Macro genetics Genetics that we can see Glofish real or fake?

4 Unit 3:Macro genetics Genetics that we can see Glow in the dark mice?

5 Unit 3:Macro genetics Genetics that we can see Belgian blue bull

6 Unit 3:Macro genetics Genetics that we can see Leading questions: 1. What is genetics? 2. What evidence do YOU know that makes genetics exist?

7 Unit 3:Macro genetics Genetics that we can see Watch this: Gregor Mendel Why was his research so significant?

8 Unit 3:Macro genetics Genetics that we can see Gregor Mendel: Studied garden peas (ok what s so important about it?) What he observed was: There was a MATHETMATICAL relationship of traits being passed down into the next generation!

9 Unit 3:Macro genetics Genetics that we can see What does this mean? If there is a mathematical relationship, then that means that genetics is NOT random! You can calculate the probability of traits being passed down.

10 Unit 3:Macro genetics Genetics that we can see Look at the ratios! They are nearly a 3 to 1 ratio!

11 Unit 3:Macro genetics Genetics that we can see How does this genetics stuff all work?

12 Unit 3:Macro genetics Genetics that we can see Let s review Mitosis Meiosis When an organism grows, it undergoes mitosis. Mitosis is simply cells dividing by copying the genetic material (DNA). Every result is the same as before.

13 Unit 3:Macro genetics Genetics that we can see Let s review Mitosis The cellls will grow by copying old cells. The DNA will be the same.

14 Unit 3:Macro genetics Genetics that we can see Let s review Mitosis Meiosis In Meiosis, this is the process that leads to our genetic diversity. Let s take a closer look.

15 Unit 3:Macro genetics Genetics that we can see Let s review Meiosis Every sex cells produced will be different

16 Unit 3:Macro genetics Meiosis Meiosis The process that s saving our humanity, maybe. Yeung

17 Unit 3:Macro genetics Meiosis Leading question How come you and your sibling(s) do not look exactly alike? Jessica Simpson Ashlee Simpson

18 Unit 3:Macro genetics Meiosis Meiosis Meiosis is the process in which sperm and egg cells are produced. Sperm and egg cells are called reproductive cells (sex cells) in comparison to somatic cells (any other body cell. What makes sex cells different than somatic cells is that every sex cell will contain traits from the mother and father randomly!

19 Unit 3:Macro genetics Meiosis Inside the testis, sperm is produced. The process sperm is produced is via meiosis.

20 Unit 3:Macro genetics Meiosis What does meiosis look like?

21 Unit 3:Macro genetics Meiosis This is meiosis Yep there s a lot of stuff happening

22 3. Crossing over occurs in meiosis which allows the exchange of genetic material. Unit 3:Macro genetics Meiosis Key things to note for meiosis: 1. Meiosis is cell division (from one cell to 4 cells) 2. You start off with a cell with traits from both parents (pair of chromosomes called diploid = 2n) but ends up with just 1 copy (single chromosome that has been mixed. Haploid = 1n)

23 Unit 3:Macro genetics Meiosis Mapping out meiosis

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25 Unit 3:Macro genetics Meiosis Key Terms to know for Meiosis Chromosomes: Humans have 46 chromosomes or 22 pairs homologous chromosomes. Chromosomes are large strands of DNA Homologous Chromosomes A pair of chromosomes that are similar in length and genes. (1 from dad and 1 from mom). Sister Chromatids Each individual chromosome that has been replicated during meiosis

26 Unit 3:Macro genetics Meiosis Note the differences between the terms. Homologous chromosomes are chromosomes that are similar with genes/traits such as hair colour from dad and hair colour from mom NOT hair colour and genes for big toe.

27 Unit 3:Macro genetics Meiosis This chromosome accounts for brown hair This chromosome accounts for blonde hair Crossing over happens at Chiasma where DNA is exchanged from one chromosome to the other homologue Results in genetic variation between sperm / egg cells

28 Unit 3:Macro genetics Meiosis Mitosis Somatic cells (cells that are NOT sex cells) No exchange of material (resulting cells are same as parent) Occurs in 1 phase Resulting cells are diploid (2N) or have both sets of chromosomes 2 cells are formed Meiosis Only in sex cells (gametes Exchange of genetic material Occurs in 2 phases Resulting cells are haploid (1N) or have 1 half set of the chromosomes 4 sex cells are formed (egg cells degenerate to result in 1)

29 Unit 3:Macro genetics Chromosomes Let s talk about our chromosomes

30 Unit 3:Macro genetics Chromosomes Chromosomes are structures found inside the nucleus of the cell. It is basically a structure that is a long spool of DNA wrapped around. It carry all of our genes Humans have 46 chromosomes or 23 pairs.

31 Unit 3:Macro genetics Chromosomes 22 of the 23 pairs are autosomes, which are chromosomes for all of our traits while the 23 rd pair of chromosomes (x and y) determine the sex of the organism. XX = females XY = males

32 Unit 3:Macro genetics Non-disjunction disorders Non-disjunction disorders

33 Unit 3:Macro genetics Non-disjunction disorders What happens when you have an extra chromosome or missing chromosome?

34 Unit 3:Macro genetics Non-disjunction Non-disjunction disorder Non-disjunction disorder is when chromosomes fail to separate during meiosis leaving an extra or missing chromosome in the sex cell. disorders

35 Unit 3:Macro genetics Non-disjunction disorders As a result, the sperm or egg cell will not have or will have an extra homologous chromosome.

36 Unit 3:Macro genetics Non-disjunction disorders When fertilization occurs, the zygote (sperm + egg) will have an uneven number of chromosome.

37 Unit 3:Macro genetics Non-disjunction disorders Here are some non-disjunction disorders: 1. Down Syndrome trisomy 21 (extra chromosome on chromosome #21). 2. Klinefelter syndrome Extra X chromosome in males resulting in XXY. 3. Turner syndrome Missing X chromosome in females resulting in just X.

38 Unit 3:Macro genetics Non-disjunction disorders Refer to the readings for each.

39 Unit 3:Macro genetics Non-disjunction disorders Klinefelter s syndrome

40 Unit 3:Macro genetics Non-disjunction Turner s syndrome disorders

41 Unit 3:Macro genetics Non-disjunction disorders Trisomy 18 Edward s syndrome Extra chromosome on #18 Less than 10% will see their 1 st birthday

42 Unit 3:Macro genetics Non-disjunction disorders Trisomy 13 Patau syndrome Extra chromosome on #13 Only 5 10% will see their 1 st birthday. Most will die within first days or weeks of life.

43 Unit 3:Macro genetics Non-disjunction disorders So how do we determine if a fetus has a nondisjunction disorder?

44 Unit 3:Macro genetics Amniocentesis Amniocentesis Takes sample of amniotic fluid (the liquid the fetus grows in) from the mother In the fluid, there are cells where the baby has shed from his/her skin and bladder

45 Unit 3:Macro genetics Karyotyping The cells are then analyzed for the number of chromosomes present. This method is called Karyotyping.

46 Unit 3:Macro genetics Karyotyping Karyotyping pairs up all of the homologous chromosomes and labeled 1 to 21

47 Unit 3:Macro genetics Karyotyping Male Female

48 Unit 3:Macro genetics Karyotyping Downsyndrome (Trisomy 21)

49 Unit 3:Macro genetics Karyotyping Kleinfelter Syndrome XXY

50 Unit 3:Macro genetics Karyotyping Turner Syndrome (X)

51 Unit 3:Macro genetics Summary Summary In this set of notes, you should have learnt the following: Mitosis Meiosis and their importance Chromosomes in humans Non-disjunction disorders Karyotyping