Human Heredity
Name: ____________________________ NOTES#
Date: ______________
Color: _______________
I. Chromosomes:
1. Walter Sutton in 1902 proposed the Chromosome Theory of Inheritance that said genes are located on
chromosomes
2. For most of the life of the cell, chromosomes are located in the nucleus and called ________________
3. Before a cell gets ready to divide, each chromosome is duplicated & ____________________________
____________________________________________________
4. The two DNA strands are _______________________and are connected by the ___________________
5. While they are still attached, the duplicated chromosomes are called ___________________________
6. ___________________ restores the ____________ chromosome number in the __________________
7. Humans have _______________________________________
8. Chromosomes can be categorized as two types --- autosomes & sex chromosomes
a. _______________________ are non-sex chromosomes that are the same number in both sexes
b. ____________________________________ determine if the individual is male or female
c. Sex chromosomes in the human female are XX and those of the male are XY
II. Sex Linkage:
1. Thomas Hunt Morgan worked with fruit flies & confirmed that genes were on chromosomes
a. Fruit flies are cheaply raised in common laboratory glassware
b. Females only mate once and lay hundreds of eggs
c. Fruit fly generation time is short, allowing rapid experiments
2. Besides genes that determine sex, sex chromosomes carry many genes for traits _________________
__________________________
3. Sex-linked gene is any gene located on the X chromosome that are missing on the ________________
4. Sex-linked alleles are designated as superscripts to X chromosome
5. Heterozygous females are __________________________ that do not show the trait but can pass it on
6. Males are never carriers but express the one allele on the ____________________________________
7. ________________________________________ is sex-linked recessive
8. What are the results of crossing a colorblind male with a female carrier for colorblindness?
a. DO THIS ON THE BACK PAGE
9. In humans, another well-known sex-linked traits is _________________________________________
10. One of the most famous genetic cases involving hemophilia goes back to Queen Victoria who was a
carrier for the disorder and married Prince Albert who was normal
11. Their children married other royalty, and spread the gene throughout the royal families of Europe
III. Chromosome Mapping:
1. Humans have few offspring
and a long generation time so
biochemical methods are used
to map human chromosomes
called the
_________________________
_________________________
IV. Chromosome Mutations:
1. Mutations are changes in
_________________________
_________ that can be passed on to offspring
2. Mutations increase the number of _______________________________________ that occur
3. Chromosomal mutations include changes in chromosome ___________________________________
4. Monosomy occurs when an individual has only ________ of a particular type of chromosome
a. _______________________ (X0) is an example of monosomy
5. Trisomy occurs when and individual has three of a particular type of chromosome
a. Examples of trisomy include __________________________________ and Down Syndrome
or __________________________ where the individual has three 21st chromosomes
6. Both monosomy & trisomy result when chromosomes __________________________ during meiosis;
called nondisjunction and may be lethal (deadly)
7. Deletions occur when the end of a chromosome _________________________
a. ____________________________________________ (results in retardation & a cat-like
cry) is due to a deletion of a portion of chromosome 5
8.
9. Environmental factors including ______________________________________, can cause
chromosomes to break causing a change in chromosomal structure
V. Karyotypes
1. Karyotypes shows the complete _______________________________ of chromosomes
2. They are grouped pairs, arranged in order of _____________________________________.
3. Used to help explore the
_____________________________________
4. The human genome is a full set of genetic material
VI. DNA:
1. Chromosomes are made of _____________
2. Genes must be able to supply _____________________________
for each cell process and for ________________________ cell
structures
3. ___________________________ (early 1950’s) used x-rays to photograph DNA crystals
4. Erwin Chargaff (1950’s) determined that the amount of __________ and amount of _________
in DNA; called ______________________________
5. _____________________________ discovered double helix shape of DNA & built the 1st model
6. Watson and Crick build models of DNA. They concluded that DNA resembles a ______________
______________________ shape known as a _________________________________
VII. Mutations:
1. A chemical or physical agent in the environment that causes a change in the sequence of the
DNA is called a ______________________________
a. Chemical: _________________________________, a few natural plant alkaloids,
___________________________, ______________________________
b. Physical: ____________________________________________ (x-rays and UV light)
2. Mutationa. _______________________ is Latin for “to change.”
b. Mutations are ______________________ within the original sequence of DNA
3. ______________________________________- Shift the entire frame of DNA down a few bases
4. _____________________________- Delete or add one single point in the DNA
a. Deletion-Removal of one base
b. Addition-Addition of one base
5. Some diseases caused by mutations:
a. Huntington's Disease
b. Muscular Dystrophy
c. Sickle cell anemia
VIII. Genetic Engineering:
1. A __________________________ is a diagram for tracing a trait through generation of a family
2. In _______________________________________ organism with certain desirable
characteristic are mated to produce a new breed
3. This process of _________________________________________ allows scientists to transfer
genes from one organism to another
IV. Reproduction:
1. In _________________________ reproduction, only one parent cell is needed for reproduction
2. In ___________________ reproduction, two parent cells join together to form a new individual
3. Human body cells have __________________ chromosomes
4. Human sex cells have only ______________chromosomes- _____________________________
a. Male sex cells are called ______________________
b. Female sex cells are called ____________________________
5. ______________________ produces new sex cells with half the usual number of chromosomes.
6. __________________ are located on _____________________
7. ______________________________________ carry genes that determine whether the
offspring is __________________________________.
a. Females have ___________________________________
b. Males have an ______________________________ and a ______________________
8. Explain the difference between sex cells and sex chromosomes?