Human Inheritance Flashcards
What is a karyotype?
a visual representation of the chromosomes in an individual’s cells arranged in a specific order according to size, shape, and other characteristics; an individual’s complete set of chromosomes
How can a karyotype be useful when looking for genetic disorders?
it allows for the detection of changes in chromosome number, structure, or organization. These changes are often associated with genetic disorders, such as Down syndrome, Turner syndrome, and Klinefelter syndrome.
autosomes
An autosome is a chromosome that is not involved in determining an individual’s sex. Autosomes are paired chromosomes that carry genetic information for most of an individual’s inherited traits, such as eye color, hair color, and height
sex chromosomes
Sex chromosomes are the pair of chromosomes that determine an individual’s sex. In humans, there are two sex chromosomes, X and Y. Females have two X chromosomes, while males have one X and one Y chromosome. The sex chromosomes carry genes that are responsible for the development of sexual characteristics, such as reproductive organs and secondary sex traits.
What is a pedigree?
diagrammatic way of visualizing inheritance from generation to generation
What information can you learn from a pedigree?
genotypes of family members, presence of new mutations, pattern of inheritance, whether the trait or condition is transmitted from one generation to the next, or whether it skips generations.
Name some common genetic disorders caused by abnormal chromosome number?
Down syndrome- extra copy
turner syndrome- females that only have one functioning x chromosome
Jacobsen syndrome
Mutations in which types of cells are passed on to future generations?
Mutations that occur in the (sex cells) DNA of germ cells, which are the cells that give rise to sperm and eggs, can be passed on to future generations. This is because when a sperm and egg unite during fertilization, their genetic material combines to form a new individual with a unique combination of inherited traits.
Are recessive or dominant genetic disorders more common in the human population?
Recessive disease mutations are much more common than those that are harmful even in a single copy, because such “dominant” mutations are more easily eliminated by natural selection
Understand how X-linked genes are inherited.
For X-linked genes, females can inherit two copies of the gene, one from each parent, while males can only inherit one copy, from their mother. If the gene is dominant, both males and females can inherit the trait if they have at least one copy of the mutated gene. If the gene is recessive, females need to inherit two copies of the mutated gene, one from each parent, to express the trait, while males only need to inherit one copy, from their mother. People can also be carriers in females, carriers can pass the mutated gene on to their offspring, while in males, the mutated gene will always be expressed because there is no second X chromosome to provide a normal copy of the gene.
Name the type of inheritance (autosomal or sex chromosome, dominant or recessive) that controls each of these common genetic disorders.
a. Cystic fibrosis
b. Hemophilia
c. Sickle cell anemia
d. Huntington’s disease
a. Cystic fibrosis is an autosomal recessive genetic disorder.
b. Hemophilia is an X-linked recessive genetic disorder.
c. Sickle cell anemia is an autosomal recessive genetic disorder.
d. Huntington’s disease is an autosomal dominant genetic disorder.
