Chapter 14 Flashcards
Karyotype
A picture of chromosomes arranged together in pairs.
When is the karyotype taken?
During mitosis.
Sex chromosomes
The two of the 46 chromosomes that determine the sex.
Autosomes or Autosomal chromosomes.
The remaining 44 chromosomes (not the sex chromosomes).
What do sperm carry?
Half of all sperm carry an X chromosome (23,X) and half carry a Y chromosome (23, Y)
What do eggs carry?
All human eggs carry a single X chromosome (23,X)
Pedigree Chart`
chart that shows the relationships within a family. Genetic counselors analyze pedigree charts to infer the genotypes of family members.
How many genes dopes the human genome have?
It include tens of thousands of genes.
What major event happened in 2003?
The DNA of the human genome was published.
What are two of the best known blood group genes?
The ABO blood groups and the Rh blood groups.
What are many disorders caused by?
They are caused by autosomal recessive alleles.
What are some disorders caused by recessive alleles?
They are Albinism, Cystic fibrosis, Galactosemia, Phenylketonuria (PKU), and Tay-Sachs disease.
True or false. The dominant allele are not expressed when the recessive allele is present.
False. The effects of a dominant allele are expressed even when the recessive allele is present.
What is sickle cell disease caused by?
It is casued by a codiminant allele. It is found in about 1 out of 500 African Americans.
What does cystic fibrosis do?
It produces a thick, heavy mucus that clogs their lungs and breathing passageways
What does sickle cell disease do?
Hemoglobin is the protein in red blood cells that carries oxygen. In the sickle cell allele, just one DNA base is changed. As a result, the abnormal hemoglobin is less soluble than normal hemoglobin. Low oxygen levels cause some red blood cells to become sickle shaped.
What determines sex?
The X chromosome and the Y chromosomes
determine sex.
Sex-linked genes
Genes located on the X chromosome and the Y chromosomes
What is color blindness associated with?
Three human genes associated with color vision
are located on the X chromosome.
True or false: The Y chromosome is
much smaller than the X
chromosome
True
nondisjunction
The most common error in meiosis occurs when
homologous chromosomes fail to separate.
What happens if nondisjunction occurs?
If nondisjunction occurs, abnormal
numbers of chromosomes may find their
way into gametes, and a disorder of
chromosome numbers may result.
How many base pairs in in DNA?
There are roughly 3 billion base pairs in your DNA.
DNA fingerprinting
DNA fingerprinting analyzes sections of DNA that
have little or no known function but vary widely
from one individual to another.
