6. Chromosomal Variation

Which of the following represents the chromosomal segregation into gametes after a reciprocal translocation caused by adjacent-1 segregation? N=Normal chromosome T = Tanslocated chromosome

Which of the following ways reciprocal translocated chromosomes are sorted produces viable gametes?

An individual heterozygous for a reciprocal translocation has the following chromosomes. Which chromosomes do the gametes receive after alternative segregation? 

A B • C D E F G                        J K • L M N O P 

A B • C D N O P                       J K • L M E F G 

An individual heterozygous for a reciprocal translocation has the following chromosomes. Which chromosomes do the gametes receive after adjacent-1 segregation? 

A B • C D E F G                J K • L M N O P 

A B • C D N O P               J K • L M E F G 

An individual heterozygous for a reciprocal translocation has the following chromosomes. Which chromosomes do the gametes receive after adjacent-2 segregation? 

A B • C D E F G             J K • L M N O P 

A B • C D N O P            J K • L M E F G 

How many chromosomes does a person who is a carrier for familial down syndrome caused by a robertsonian translocation have?

From the following list, identify the types of chromosome changes you expect to show phenotypic consequences.

reciprocal balanced translocation

An animal heterozygous for a reciprocal balanced translocation has the following chromosomes:
           MN • OPQRST
           MN • OPQRjkl
           cdef • ghijkl
           cdef • ghiST

Identify the gametes produced by adjacent-2 segregation. Which if any of these gametes are viable?

An animal heterozygous for a reciprocal balanced translocation has the following chromosomes:
           MN • OPQRST
           MN • OPQRjkl
           cdef • ghijkl
           cdef • ghiST

Identify the gametes produced by adjacent-1 segregation. Which if any of these gametes are viable?

An animal heterozygous for a reciprocal balanced translocation has the following chromosomes:
           MN • OPQRST
           MN • OPQRjkl
           cdef • ghijkl
           cdef • ghiST

Identify the gametes produced by alternate segregation. Which if any of these gametes are viable?

An animal heterozygous for a reciprocal balanced translocation has the following chromosomes:
           MN • OPQRST
           MN • OPQRjkl
           cdef • ghijkl
           cdef • ghiST

Diagram the pairing of these chromosomes in prophase I.

A boy with Down syndrome (trisomy 21) has 46 chromosomes. His parents and his two older sisters have a normal phenotype, but each has 45 chromosomes.

What is the probability the next child of this couple will have a normal phenotype and have 46 chromosomes? Explain your answer.

A boy with Down syndrome (trisomy 21) has 46 chromosomes. His parents and his two older sisters have a normal phenotype, but each has 45 chromosomes.

What term best describes this kind of chromosome abnormality?