Sexual Reproduction And Meiosis

1. Sexual Reproduction And Meiosis

2. - sexual reproduction- 2 _____ cells, _____ and _________ come together • sperm- ______ sex cell, formed in males reproductive organs • eggs- _________ sex cell, formed in females reproductive organs • fertilization- __________ of egg and sperm • zygote- the _______ that forms from egg and sperm • once ______________ has occurred a cell (___________) is formed with unique _________ sex 1. Important Terms and facts: egg sperm male female joining cell fertilization zygote identity

3. 2. 2 types of cells: • _______ cells • _______ cells body sex skin organs • bone, _________, tissues, __________ • contain ___ chromosomes (__ pairs) • known as ___________ cells or cells with __________ 3. Body Cells 46 23 diploid pairs sperm 4. Sex Cells • egg and __________ • ___ chromosomes- ______ paired • known as _________ cells or “________ form” cells not 23 haploid single

4. duplicate • process used to _______________ haploid ______cells • does not occur until ____________ 5. Meiosis sex puberty twice - we would have _________ the amount of chromosomes 6. What would happen in sexual reproduction if we made diploid cells?

5. 7. Formation of a zygote • 2 _________ cells combine to make a __________ cell called a _________ • egg + sperm = zygote • haploid 23 + haploid 23 = diploid 46 • - this is why you have ___________ from both parents haploid diploid zygote features

6. meiosis 8. Meiosis vs. Mitosis • __________ is for the duplication of haploid (_____) cells • _________ is for the duplication of diploid (______) cells sex mitosis body

7. twice 9. Steps of Meiosis • the __________ divides _______, this is called Meiosis I and Meiosis II • 1. Interphase • 2. __________ I • 3. Metaphase I • 4. __________ I • 5. Telophase I • 6. __________ II • 7. Metaphase II • 8. __________ II • 9. Telophase II nucleus Prophase Anaphase Prophase Anaphase

8. 10. Interphase • chromatids are duplicated and called _____________ • 23 x 2 = ____ chromosomes chromosomes 46

9. chromatids 11. Prophase I • duplicated ______________ join to form chromosomes • _______________occurs when chromosomes _______ and _____________ genetic information Crossing over coil exchange chromosomes 12. Metaphase I • pairs of _______________ line up in the __________ • _______________of each chromosome attaches to one ____________________ middle centromere spindle fiber

10. chromosomes 13. Anaphase I • the pairs of ________________ move to _____________ ends of the cell • each chromosome still has ____ chromatids opposite 2 14. Telophase I cytoplasm • _____________ divides • ___ new cells form 2

11. Meiosis 15. Meiosis II • both cells from _________ I undergo _____________ II • does not begin until ______________ Meiosis puberty 16. Prophase II - _____________________ and ________ fibers reappear chromosomes spindle

12. centromere 17. Metaphase II • each _______________ attaches to ____ spindle fibers • chromosomes line up in the ___________ 2 middle

13. 18. Anaphase II chromatids - centromere and _____________ separate and move to ______________ ends of the cell opposite 19. Telophase II disappear • spindle fibers ______________ • ____________________forms around chromosomes • cytoplasm ___________(cytokinesis) nuclear membrane divides each cell produced in meiosis has _____chromosomes 23

14. chromosome disorders may occur such as ___________, Down syndrome, __________ syndrome, Edward’s syndrome, ______________ syndrome, and Turner’s syndrome • _________________- when a pair of chromosome doesn’t ______________- often fatal to fetus 1. What happens if a cell is made with too many or too few chromosomes?

15. extra chromosome _______ • specific ____________ features, _________ stature, __________ defects • often have ______________ diseases, a shorter _______________, and some degree of ___________ retardation • range from ____________ to ________ 2. Down Syndrome

16. extra chromosome _____ • severe ______, ________ and _________________ effects • often have a cleft ____________ • usually don’t live longer than a few _____________ 3. Patau Syndrome 4. Edward’s Syndrome • extra chromosome ____ • affects all ____________ in some way • usually don’t live longer than a few ______________

17. 5. Klinefelter’s syndrome • extra _____ chromosome in sex determining chromosomes (______) • they are ________but have some _____________ characteristics 6. Turner’s syndrome • only have ____ chromosome- missing other ____ • ________with only __ chromosomes • _________ in stature and do not ____________

18. 7. Fragile X syndrome • caused by a ______________ on the ____ chromosome • occurs mostly in __________ • causes slow ________, developmental ____________, mental ______________, and _____________ problems such as autism