1. By Mr. Simonds EQ: How are traits passed from parents to offspring?
Meiosis & Karyotypes
By Mr. Simonds
EQ: How are traits passed from parents to offspring?

2. Vocabulary
Meiosis – A type of cell division that produces sex cells with half the normal number of chromosomes.

3. Meiosis I

4. Meiosis II Prophase II Metaphase II Anaphase II Telophase II
Meiosis I results in two haploid (N) daughter cells, each with half the number of chromosomes as the original.
Prophase II
Metaphase II
Anaphase II
Telophase II
The chromosomes line up in a similar way to the metaphase stage of mitosis.
The sister chromatids separate and move toward opposite ends of the cell.
Meiosis II results in four haploid (N) daughter cells.

5. Gametes – Sex cells (sperm and eggs)
Haploid – The name for a cell that has half of its normal number of chromosomes. Ex. Gametes

7. Somatic Cells – Every non-sex cell (skin, nerves, muscle, etc)
Diploid
Diploid – The name for a cell that has two of every type of chromosome.

8. In each of our sex cells we have 23 chromosomes, one of each type.
Humans have 23 pairs of chromosomes. That makes a total of 46 chromosomes.
So our diploid number is 46.
In each of our sex cells we have 23 chromosomes, one of each type.
So our haploid number is 23.

9. Healthy Human Male

10. If the diploid number of an organism is 10, what is the haploid number?5
If the haploid number of an organism is 15, what is the diploid number?

11. Homologous Chromosomes – A pair of the same type of chromosomes
Homologous Chromosomes – A pair of the same type of chromosomes. You get one from your mom and one from your dad.

12. Review How many chromosomes would one of your skin cells have?46
What is the haploid number for humans? 23

13. Review What are gametes? How many chromosomes do human gametes have?
Sex cells (sperm and eggs)
How many chromosomes do human gametes have? 23
If an organisms haploid number is 20 what is its diploid number? 40

14. Karyotyping
By Mr. Simonds

15. What is a Karyotype
Karyotype - a picture of a person’s chromosomes matched by pairs and arranged in order.
To make a karyotype you need a picture of a persons DNA in chromosome form
Then you match up chromosomes in pairs (23 pairs, including sex chromosomes)

16. Reasons for Karyotyping
To check for genetic (chromosomal) disorders such as:
Down syndrome
Klinefelter syndrome
Turner syndrome

17. What are the pairs?
Autosomes – Chromosomes 1-22, they control most of the traits that make you.

18. What are the pairs?
Sex Chromosomes – The 23rd pair of chromosomes (X & Y), they determine your sex (male or female).

19. Chromosomes & Gender A female has two X chromosomes.
A male has one X and one Y chromosome.
As long as there is a Y chromosome the fetus will become a male.

20. Karyotype of a Healthy Female

21. Karyotype of a Healthy Male

22. What is Down Syndrome?
Down Syndrome – A disorder caused by an extra 21st chromosome. It causes delays in physical and intellectual development
Also called Trisomy 21
Occurs in 1 out of every 800 live births
Down syndrome is not related to race, nationality, religion or socioeconomic status. The most important fact to know about individuals with Down syndrome is that they are more like others than they are different.

24. Down Syndrome

25. Turner Syndrome
Turner Syndrome – caused by having only one X chromosome. People with Turners become female.
Occurs in 1 in 2000 to 1 in 2500 live births.
Symptoms include short stature and lack of ovarian development. (They are sterile.)

27. Klinefelter Syndrome
Klinefelter Syndrome – Caused by having two X and one Y chromosome. People with this become male.
Occurs in 1 in 500 to 1 in 1000 live births.
They are often tall and usually do not develop secondary sex characteristics such as facial hair, or underarm and pubic hair.

29. How do these disorders occur?
Metaphase II
Prophase II
*Note that two of the chromosomes did not separate during anaphase
Anaphase II

30. How do these disorders occur?
Non-disjunction – When chromosomes fail to separate during meiosis. This causes most chromosomal disorders.
*Note that two of the chromosomes did not separate during anaphase
Anaphase II

31. How non-disjunction occurs.
Gamete A
Gamete B
Telephase
An individual resulting from Gamete A may have Down syndrome, trisomy 21, or Klinefelter syndrome. An individual resulting from Gamete B may have Turner syndrome.
* Note that Gamete A has one extra chromosome and Gamete B has one less chromosome

32. Mitosis & Karyotypes (+ a little DNA)
Review
Mitosis & Karyotypes
(+ a little DNA)

33. Meiosis Does the father or the mother cause the sex of the baby? Why?
The mother can only donate an X chromosome

34. Healthy Human Female

35. Metaphase

36. Down Syndrome

37. Prophase
Nucleus membrane breaking down
Chromosomes formed

38. Healthy Human Male

40. Meiosis What cells undergo Meiosis?
Sex Cells
How much DNA or Chromosomes do you have after Meiosis?
Half as much
What cells undergo Mitosis?
Body cells (Everything except for Sex cells)

41. Meiosis What does Haploid mean?
Half the number of Chromosomes
An organisms Diploid number is 12. What is its haploid number? 6
You have two of each type of chromosomes. Where do you get them from?
One from your mom & one from your dad

42. Chromosomes separating
Anaphase
Chromosomes separating

43. What happened?
Non-Disjunction
Metaphase II
Anaphase II

44. Telephase/ Cytokinesis

45. Which ones pair together?

46. DNA What do you make during Transcription?
mRNA
What process makes protein from mRNA?
Translation