HUMAN HEREDITY OBJECTIVES: 14.1 Identify the types of human chromosomes in a karyotype. Explain how sex is determined. Explain how pedigrees are used to study human traits. Describe examples of the inheritance of human traits. Explain how small changes in DNA cause genetic disorders.

Cell biologist analyze the ___________ by taking photographs of cells in _____. A picture of chromosomes arranged in this way is known as a __________. A _____ karyotype has __ pairs of chromosomes ____ _____

These karyotypes are the result of a ______ sperm, carrying 23 chromosomes, _______ a haploid egg, also carrying 23 chromosomes. The diploid ______, or fertilized egg, contains the full compliment of ___ chromosomes (23 pairs). Two of the 46 are known as ___ chromosomes, because they determine and individual’ sex. _____ have two copies of a large X chromosome. ____ have one X and one small Y chromosome.

Punnet square Males and females are born in a roughly 50:50 ratio because of the way in which sex cells segregate during ________.

All human eggs (___) cells carry a single X chromosome (23,X). Half of all sperm cells carry an __ chromosome (23,X) and half carry a _chromosome (23,Y). This ensures that about half of the zygotes will be 46,XX and half will be 46, XY.

A _______ chart shows the relationship within a family. It shows how the _____ is transmitted through the generations.

The human _______ contains tens of thousands of genes. The _____ sequences on these genes carry information for specifying many __________, from the color of your eyes to the detailed structures of proteins within your cells.

________ blood comes in a variety of genetically determined blood groups. A number of genes are responsible for human blood groups, but the best known are the ___ blood groups and the __ blood groups. The Rh is determined by a single gene with two alleles- _______ or _______. The positive allele is ________. Individuals with two negative _____ are Rh negative.

There are three alleles for this gene __, __, and __. IA and IB are ___________. These allele produce molecules known as ______ on the surface of the RBC. If you have IA and I B you produce both A and B antigens, making you blood type __. The i allele is ________. IAIA and IAi produce only A antigen, making the blood type A.

If you have IBIB or IBi are type B. If you are _________ for the i allele (ii) you produce __ antigens and have the blood type O. When referring to blood groups, usually both groups are mentioned.

One of the first genetic disorders to be understood is ________________ (PKU). Phenylalanine is an ____ acid found in ____ and other foods, which can build up in the first years of life of a child and cause severe __________. Newborns can be tested for ____ and be placed on low-phenylalanine diet, that prevents most defects. ___-_____ disease is another disease caused by _________ alleles.

Disorders in humans ______ _________ __________ ___________ ___________________

In both cystic fibrosis and sickle cell disease, a small change in the DNA of ______ gene affect the structure of a protein, causing a serious genetic disorder. CF is caused by a recessive gene on chromosome __. It is caused by a _______ of 3 base pairs in the middle of a sequence for a protein. Sickle cell disease cause RBC to be _____ and _______.

These RBC are more _____ than normal RBC and tend to get stuck in the _________ (narrowest blood vessels). Because of this the blood stops moving through these vessels, damaging cells, ______, and organs. It produces physical weakness and damage to the brain, heart, and _______ (it can be fatal). Sickle cell occurs when the amino acid _____ is substituted for glutamic acid.

People who are _________ for the sickle cell allele are generally healthy. They are resistant to _______, which is caused by a parasite

A human _____ cell contains more than ___ billion base pairs of DNA. Chromosome __ and __ are the smallest human _______. The ___ pair is called the sex genes, because they determine the sex of the _____. Sex-linked genes are located on the __ chromosome (____________). The most common is not being able to tell ___ or ______.

____ have only one X chromosome. All sex-linked alleles are ______ in males, even if they are ______. XC Y XC XCXc XCY XCXc XcY Xc

___________ is caused by a protein necessary for blood clotting is missing. A ________ allele on either of the X chromosome of the female can cause it. Hemophilia can be treated by injections of normal clotting proteins, which are now produce by ________________ DNA.

Duchenne Muscular Dystrophy is a sex-linked disorder that results in the progressive weakening and loss of ________ muscle. It is caused by a defective version of the gene that codes for muscle _______.

Duchenne MD

Females have two __ chromosomes, one is randomly turned-off and forms a dense region around the nucleus called a ___ body. Barr bodies are ___ found in males because they have only one X chromosome.

__________ is an abnormal number of chromosomes may find their way into _____, and a disorder of chromosome numbers may result. If two copies of an ________ chromosome fail to separate during ______, and individual may be born with three copies of a chromosome (_____). The most common trisomy is one that involves the __st chromosome and is known as known as ____ _______.

Down syndrome is caused by nondisjuction of the 21st chormosome

_____ syndrome is a sex chromosome disorder caused by nondisjunction (___). ______ with Turner’s syndrome are _____ and their sex organs do not ______ at puberty. ________ syndrome (47,XXY) is also cause by nondisjunction. The extra X interferes with _____ and usually prevent the individual from ___________. Klinefelter’s syndrome can also be XXXY or XXXy.

There have been no reported instances of babies being born ______ and X chromosome. This indicates that the X chromosome is vital for _____ and ________ of the embryo. If there is a Y chromosome present the child is always ___. If there is an absents of a Y chromosome the child will be _______.

HUMAN MOLECULAR GENETICS OBJECTIVES: 14.3 State the goal of the Human Genome Project. Describe how researchers are attempting to cure genetic disorder.

DNA fingerprinting is used to identify individuals, because of the complexity of the human genome. No individual is exactly like any other genetically, except – identical twins. The Human Genome Project is an ongoing effort to analyze the human DNA sequence. Gene ______ is the replacing of an absent or faulty gene by a normal, working gene.