1. Cells!
Created by Educational Technology Network

2. Meiosis vs. Mitosis
Punnetts
Meiosis
Mistakes in Meiosis
Pedigrees 10 20 30 40 50

3. Question
Cells that undergo mitosis end with how many sets of chromosomes and what are they called?

4. Answer 1 – 10
2; diploid(2n) Cells that undergo mitosis go through one division and end with 2 sets of chromosomes (2n)

5. Question
Which process is shown in this picture and what is the word for the final number of chromosome sets in this process?

6. Answer 1 – 20
Meiosis; Haploid This picture shows the process of meiosis. In the first step there are two sets of chromosomes that are replicated (S phase of interphase) and then divided twice, resulting in a singular set (haploid) of chromosomes in each gamete.

7. C B A Which of the following would be found in a gamete?
Question
Which of the following would be found in a gamete? B C A

8. Answer 1 – 30
A Twenty-three unreplicated chromosomes would be found in a human gamete.

9. Question
No matter which process, mitosis or meiosis, the hierarchy of genetics remains the same.
Use the letters to order the following from largest to smallest.
Chromosome
Deoxyribose
Gene
Genome
Nucleotide

10. Answer 1 – 40
D, A, C, E, B
Genome>Chromosomes>Genes>Nucleotides>Deoxyribose
The GENOME includes all the DNA of an organism. It is divided up into separate collections of DNA called CHROMOSOMES. Chromosomes are made of smaller segments that code for a protein called GENES. Genes are made of sequences of NUCLEOTIDES. DNA Nucleotides are made of 3 parts; a nitrogenous base, a phosphate group, and DEOXYRIBOSE sugar.

11. Describe the three processes that occur in Meiosis but NOT in mitosis?
Question
Describe the three processes that occur in Meiosis but NOT in mitosis?

12. Answer 1 – 50
Crossing over- genetic material is traded during Prophase I
Two chromosomal divisions instead of one
Homologous chromosomes separate (anaphase I) AND sister chromatids separate (anaphase II)

13. Question
A heterozygous organism is crossed with another heterozygous organism. What percent of their offspring is homozygous?

14. 50 percent Remember, both BB and bb are homozygous
Answer 2 – 10
50 percent Remember, both BB and bb are homozygous

15. Question
A heterozygous blue flower is crossed with a yellow flower. Assuming complete dominance, what percent of offspring will be blue?

16. Answer 2 – 20
50 percent Heterozygous blue = Bb Yellow must be = bb because complete dominance means the heterozygote shows the dominant phenotype.

17. Question
Complete the following probability calculation: Mother: AaBbCc Father: aaBBCc Desired offspring:AaBbCc

18. Answer 2 – 30
1 out of 8 offspring or 12.5% You can take the long route and do a Punnett square for each character or you can use the arrow method. Either way you need to multiply the chance of the desired trait from each character. 2/4 * 2/4 * 2/4 = 8/64 = 1/8 = 12.5%

19. Question
Matthew has homozygous blood type A (IAIA). Kayli has blood type B (IB?) and her mother was blood type O (ii). What are the possible genotypes and phenotypes of Matt and Kayli’s offspring’s blood?

20. Answer 2 – 40
IAIB (50%) IAi (50%) Matt’s genotype is IAIA. Kayli’s is IBi. We know this because if she has type B blood and her mother has type O. Her mother can only donate the (i) allele. She must have received the IB from her father. Using a standard Punnett square, we find that IAIB and IAi are the only two possible genotypes of their offspring.

21. Question
Hemophilia is a sex-linked (x-linked) disorder. If Mary is a carrier of the trait and George is unaffected, what are the phenotypic probabilities of their offspring?

22. Answer 2 – 50
XHXH- Normal female (25%) XHXh- Carrier female (25%) XHY- Normal male (25%) XhY- Hemophilic male (25%) George is an unaffected male so he is XHY. Mary is a carrier, she is XHXh Use a Punnett square to determine the probabilities!

23. In what phase of meiosis does crossing over occur?
Question
In what phase of meiosis does crossing over occur?

24. Answer 3 – 10
Prophase I of meiosis

25. How do homologous chromosomes
Question
How do homologous chromosomes
(ex. chromosome 1 from mom, chromosomes 1 from dad) differ?

26. Answer 3 – 20
They differ at the A-T-C-G sequence of nucleotides for a given gene. In other words, their characters are the same but their traits vary.

27. Question
Which two of Mendel’s laws explain how genetic variation is achieved during meiosis?

28. Answer 3 – 30
Law of Independent Assortment- homologous pairs randomly pair up during Metaphase I Law of Segregation – alleles get separated during Anaphase I & II

29. Question
What are the advantages and disadvantages of asexual and sexual reproduction in terms of time and genetic variation?

30. Answer 3 – 40
Asexual- quick reproduction (+) no variation unless mutation occurs (-) Sexual- slow reproduction (-) Great generational variation (+)

31. Put these steps of meiosis in the order of occurrence:
Question
Put these steps of meiosis in the order of occurrence:
Chromosomes replicate
Crossing over occurs
Four genetically different cells are made
Homologous chromosomes pair up (synapsis into tetrads)
Sister chromatids separate

32. Answer 3 – 50
A, D, B, E, C DNA is replicated during ‘S’ phase of interphase. Homologous chromosomes synapse, forming tetrads and chiasmata where crossing over occurs. Homologous chromosomes line up randomly during metaphase and separate. During the next anaphase (II) sister chromatids separate. The end result is 4 haploid cells that are genetically unique.

33. Question
What chromosomal alteration is shown below?

34. Answer 4 – 10
Inversion The DEF gene sequence is reversed.

35. Question
What type of chromosomal alteration is shown below?

36. Answer 4 – 20
Translocation. A segment from one chromosome has been moved to a non-homologous chromosome.

37. Question
The following chromosome is found in a gamete. Which of the gene segments will be inherited by the receiving offspring?

38. Answer 4 – 30
All of them. These genes are on the same chromosome and that chromosome is already in a gamete. There is no further divisions after gametes are formed. All of these genes would be considered linked since they will be inherited together.

39. Question
Describe the individual based on the given karyotype.

40. Answer 4 – 40
It’s a male (XY) affected with Down Syndrome (Trisomy 21, three of chromosome 21)

41. Question
Sickle Cell Anemia is the result of a single nucleotide mutation which changes the amino acid sequence and therefore the protein for which the gene codes. One copy gives an individual sickle cell trait, while two gives you sickle cell disease. This affects men and women equally. What is the pattern of inheritance?

42. Answer 4 – 50
Autosomal Recessive Autosomal because it affects men and women equally. If it were x-linked it would affect men predominantly. Recessive because it requires two copies of the mutated allele to have the disease.

43. Question
What is the pattern of inheritance for this pedigree, recessive or dominant?

44. Answer 5 – 10
Recessive, it skips a generation(s) and two unaffected parents have affected children.

45. Question
What is the pattern of inheritance?

46. Answer 5 – 20
Dominant. Explained further on 5-30.

47. Question
What are the genotypes of the two parents?

48. Answer 5 – 30
Aa, Aa
The pattern of inheritance cannot be recessive (aa) because both children would also have to be recessive. So we know the shaded shapes must have at least 1 dominant allele (A). Since the parents have one affect child (A?) and one unaffected (aa) both parents must be heterozygotes. It is the only way the female child could receive 2 recessive alleles…one from mom, one from dad.

49. Question
What is the probability of the offspring being affected?

50. Answer 5 – 40
3 out of 4; 75% Using the justification in 5-30 we know that the parents must be heterozygous (Aa) Using a monohybrid cross we can determine that 3 out of 4 possibilities would be affected.

51. Question
Create a pedigree that accurately shows recessive inheritance. Include two children in the second generation, one male, one female. Include one granddaughter that is not affected. Label genotypes.

52. Answer 5 – 50

53. Final Jeopardy
Make your wager!