1. Chapter 14 The Human Genome Key Concepts: How is sex determined?
How do small changes in DNA Cause genetic disorders?

2. Human Chromosomes
A. Karyotype: A picture of chromosomes taken during mitosis and cut out and arranged into homologous pairs.

3. Let us review what we have previously learned

4. A Diploid Cell has ________ of homologous chromosomes
A Diploid Cell has ________ of homologous chromosomes. A human diploid cell has ____ chromosomes arranged in ____ pairs.
two sets 46 23
Mendelian genetics requires that organisms inherit ____________of a gene from each parent.
a single copy
In humans, ___________ (reproductive cells of egg and sperm) contain a single copy of each gene (one set of genetic information).
the gametes

5. Gametes are formed in the ______ (sperm) and __________(egg) by meiosis.
Each gamete contains 23 chromosomes (one set) or _______________ (N) of chromosomes.
____________requires the egg and the sperm to join and produce a ______ (fertilized egg) that contains 46 chromosomes (two sets) or _____________ (2N).
testes
ovaries
haploid number
Fertilization
zygote
diploid number

6. Humans have 46 total chromosomes: 44 _________ (body) that follow regular Mendelian genetics, and 2 ________________ (X and Y).
autosomes
sex chromosomes

7. A pedigree chart shows the __________ within a family and can be useful to help with genetic __________ problems within families.
It is another way to _______ an outcome of a particular cross and the ________ of the family members.
relationship
inheritance
predict
genotype

8. Pedigree Figure 14-3 A Pedigree Section 14-1
A circle represents a female.
A square represents a male.
A horizontal line connecting a male and female represents a marriage.
A vertical line and a bracket connect the parents to their children.
A half-shaded circle or square indicates that a person is a carrier of the trait.
A circle or square that is not shaded indicates that a person neither expresses the trait nor is a carrier of the trait.
A completely shaded circle or square indicates that a person expresses the trait.

14. Video Notes Worksheet: What are Pedigree Charts?

15. Video Notes Worksheet:
Pedigree Analyses
Guided Practice

16. Video Notes Worksheet:
Pedigree Summary

17. Human Genes
The ______________: Complete set of genetic information that is composed of about 30,000 genes.
human genome

18. Human Traits
Phenotypes are determined by __________as well as ______________ influenced.
_____________ influences on gene expression are not ________, but genes are.
genotypes
environmentally
Environmental
inherited

19. A trait controlled by a recessive allele results in a disorder being present only if _____________ are present.
Examples include: PKU (Phenylketonuria), Tay Sachs, Cystic Fibrosis, Albinism, and Galactosemia.
both alleles

20. A trait controlled by a dominant allele results in the disorder being present when only ________ is present.
Examples include: Achondroplasia (dwarfism), Hypercholesterolemia, and Huntington’s Disease
one allele

21. Autosomal Disorders Section 14-1 Autosomol Disorders caused by
Recessive alleles
Dominant alleles
Codominant alleles
include
include
include
Albinism
Galactosemia
Tay-Sachs disease
Huntington’s disease
Sickle cell disease
Cystic fibrosis
Phenylketonuria
Achondroplasia
Hypercholes-
terolemia

22. Huntington Disease:
It is controlled by a _________________________. The gene is located on Chromosome #4.
single dominant allele
Genetic degenerative disease that shows no symptoms until a person is in their ____________________. It progresses with gradual degeneration of their nervous system leading to loss of muscle control and mental function until death occurs.
thirties or forties

23. genetics and phenotype
IV. From Gene to Molecule The link between ______________________ is not easily determined but for several diseases we have been able to make the connection. For both ______________ and __________________ a small change in the DNA of a _____________ affects the ______________________, causing a serious genetic disorder.
genetics and phenotype
Cystic fibrosis
Sickle cell disease
single gene
structure of a protein

24. Codominant Alleles: controlled by _____________________________.
Sickle Cell Anemia is an example.
two alleles that share dominance

25. Sickle Cell Anemia
The patient’s blood cells were found to be irregularly shaped, like a _____, and this is how the disease got its name.
In normal red blood cells ___________carries _________and distributes it around the body.
In sickle cell disease, the red blood cells are sickle–shaped, causing hemoglobin to no longer carry oxygen as well and disrupts the normal functioning of cells.
sickle
hemoglobin
oxygen

26. digestive and respiratory systems
Cystic Fibrosis or “CF” is a common genetic disease. It is most common in people of Northern European decent. It is a __________________of a gene found on the # 7 chromosome and affects the__________________________________.
Recessive disease
digestive and respiratory systems

27. Figure 14-8 The Cause of Cystic Fibrosis Chromosome # 7
Section 14-1
CFTR gene
Normal CFTR is a chloride ion channel in cell membranes. Abnormal CFTR cannot be transported to the cell membrane.
The cells in the person’s airways are unable to transport chloride ions. As a result, the airways become clogged with a thick mucus.
The most common allele that causes cystic fibrosis is missing 3 DNA bases. As a result, the amino acid phenylalanine is missing from the CFTR protein.

28. The genetics: The allele for sickle cell (HS) is ___________ with the allele for normal hemoglobin (HA).
codominant
Heterozygotes (HS HA) are said to be ____ ____ __________ and have some effects of the disorder because they have both normal and sickle cell blood hemoglobin.
Sickle cell
carriers

29. DNA normal hemoglobin CAC GTG GAC TGA GGA CTC CTC
Messenger RNA sequence
GUG CAC CUG ACU CCU GAG GAG
Normal hemoglobin amino acid sequence
Val – His – Leu – Thr – Pro – Glu – Glu…
…146
DNA Sickle Cell Anemia
CAC GTG GAC TGA GGA CAC CTC
Messenger RNA sequence
GUG CAC CUG ACU CCU GUG GAG
Val – His – Leu – Thr – Pro – VAL – Glu…
…146

30. The distribution: Sickle Cell anemia is most prevalent in people of __________________.
10% of African Americans and 40% of populations in Africa and Asia carry the gene for Sickle cell anemia.
Why? The carriers for the disease have a ___________________, a dangerous disease caused by a blood parasite found in tropical areas of the world.
African descent
resistance to Malaria

31. favored by natural selection
Sickle Cell Anemia is a __________ that has provided an _________ in Malaria prone areas.
In these areas it is _________________________ and therefore Sickle Cell Anemia persists in many heterozygous individuals since the homozygous recessive condition is lethal.
mutation
advantage
favored by natural selection
HS HA
HS HS
HS HA HS HA
HS HA
HA HA

32. Section 14-2: Human Chromosomes Key concepts: Why are sex-linked disorders more common in males than in females? What is nondisjunction, and what problems does it cause?

33. males determine the sex X Y X XX XY
A. Sex Determination 1. Female _________ carry an X chromosome 2. _________ gametes can carry either an X or Y (meiosis segregates the chromosomes; _______ of the sperm carry X and ______ of the sperm carry Y) 3. In humans, _____________________________ of an offspring Female: XX male: XY
gametes
Male
50%
50%
males determine the sex X Y X XX XY X XX XY

34. Sex-linked Genetic Disorders
May be on the X or Y chromosome, but
 Most often expressed in ____________because they only have one X chromosome and thus all the alleles are expressed even if they are recessive.
usually on the X because the Y has very few genes.
males
Colorblindness is a recessive disorder in which people can’t distinguish between certain colors. ____________________ colorblindness is most common.
XC and Xc are ___________ for normal and colorblind vision.
Red-green
the alleles

35. both normal vision females.
XC XC and XC Xc are
XC Xc is a _______________________ and can pass the gene on to her sons.
Xc Xc is a
XC Y is a
Xc Y is a
both normal vision females.
carrier for colorblindness
colorblind female.
normal male and
colorblind male.

36. Colorblindness Figure 14-13 Colorblindness Section 14-2 Go to Section:
Father
(normal vision)
Normal vision
Colorblind
Male
Female
Daughter
(normal vision)
Son
(normal vision)
Mother (carrier)
Daughter
(carrier)
Son
(colorblind)
Go to Section:

37. Colorblindness Figure 14-13 Colorblindness Section 14-2 Go to Section:
Father
(normal vision)
Normal vision
Colorblind
Male
Female
Daughter
(normal vision)
Son
(normal vision)
Mother (carrier)
Daughter
(carrier)
Son
(colorblind)
Go to Section:

38. Hemophilia is a __________________________ in which one is unable to clot their blood.
Also known as
Hemophilia is caused by a defect in a gene and the protein for normal blood clotting is missing.
recessive sex-linked disorder
“bleeders disease”.

40. Royal Family and Hemophilia

41. Muscular Dystrophy is another
Here the affected individual inherits a degenerative __________disorder.
The gene that codes for a _____________ is defective. They rarely live past early adulthood.
Treatments are being explored that ___________ the defective gene.
sex-linked recessive disease.
muscle
muscle protein
replace

42. IV. Chromosomal Disorders
Whole/sets of chromosome mutations
_______________ = failure of homologous chromosomes to separate normally during meiosis
This results in a disorder of __________________
2. Examples of disorders include Down’s Syndrome, Klinefelter’s, and Turner’s Syndrome
Nondisjunction
chromosome number

43. Homologous chromosomes fail to separate
Nondisjunction
Homologous chromosomes fail to separate
Meiosis I:
Nondisjunction
Meiosis II
Go to Section:

44. Nondisjunction

45. chromosome separation
2. Examples of disorders include Down’s Syndrome, Klinefelter’s, and Turner’s Syndrome Nondisjunction disorders: Disorders in which the failure of _____________________ during one of the stages of meiosis causes a gamete to have _______________________________. Nondisjunction can occur in ___________________________.
chromosome separation
too few or too many chromosomes
autosomes or sex chromosomes

46. nondisjunction of an autosome
Down’s Syndrome: Down’s syndrome is an example of ____________________________, specifically chromosome 21.
In Down’s syndrome there is an ___________ of chromosome 21 (trisomy 21).
Doing a _____________ (display of all the chromosomes in a cell nucleus) and looking at the chromosomes under a microscope detect the extra chromosome.
Characteristics of Down’s syndrome include _________________, physically challenged, facial irregularities, and often heart defects.
nondisjunction of an autosome
extra copy
karyotype
mental retardation

47. Incidence of Down’s Syndrome and mother’s age

48. Turners Syndrome: Nondisjunction of the sex chromosomes in which
They have the chromosome makeup of _________ where “O” represents the missing chromosome.
a chromosome is missing.
45 XO
This individual is female in appearance but does not develop the female sex organs during puberty and is ________.
sterile.

49. Klinefelter’s Syndrome: Nondisjunction of the sex chromosomes in which an _____________________ is present.
They have the chromosome makeup of ________. They are ___________ in appearance and are also sterile. May also be 48 XXXY or 49 XXXXY
extra X chromosome
47XXY
male
No nondisjunctions of the sex chromosomes have ever produced and survived without an ______________. This is because the X chromosome carries many genes
X chromosome
essential for life.

50. Results mainly from nondisjunction in mother (67%)
XXY condition
Results mainly from nondisjunction in mother (67%)
Phenotype is tall males
Sterile or nearly so
Feminized traits (sparse facial hair, somewhat enlarged breasts)
Treated with testosterone injections

51. Nondisjunction of Sex Chromosomes

52. The impact of the sex chromosome nondisjunction has led us to understand the importance of the ____________ in determination of the sex of an individual. This has recently been determined to be true because the Y chromosome has been found to have a gene that turns on __________ characteristics in the embryo, even if there are many X chromosomes present.
Y chromosome
male sexual