2ND LE Flashcards
What is the order of linked genes A, B, and C?
The order of these genes on the chromosome is B-A-C.
What is a trait caused by an environmental influence that appears to be inherited called?
A trait caused by an environmental influence that appears to be inherited is called a phenocopy.
How many genes does the human mitochondrial genome consist of?
The human mitochondrial genome consists of 37 genes (that encode 13 proteins, 22 tRNAs, and 2 rRNAs).
What gene controls X inactivation?
X inactivation is controlled by the XIST gene.
What is the probability that June transmits colorblindness and ichthyosis to his son?
The probability that he transmits both traits to his son is 0% (sons inherit X-chromosome from the mother).
What are acridine dyes?
Acridine dyes are mutagens that disrupt the reading frame of the gene.
What is the characteristic shape of the mathematical plot for a multifactorial, polygenic trait?
The characteristic shape is a bell-shaped curve.
What are traditional ways of evaluating multifactorial traits?
Traditional ways include empiric risk and heritability.
What are DNA sequences that contribute to polygenic traits called?
They are called quantitative trait loci (QTLs).
What are endorphins in relation to opiates?
Endorphins are the human equivalent of opiates.
Which neurotransmitters might contribute to causing autism if levels are abnormal?
Serotonin and GABA.
What does schizophrenia mean?
Schizophrenia means ‘split mind.’
What may a person with narcolepsy experience?
A person with narcolepsy may experience cataplexy in which he or she suddenly collapses.
What does it indicate if a cancer cell develops tumors in a healthy mouse?
This experiment indicates that cancer is heritable/transplantable.
Where do mutational hot spots occur most often?
They occur most often in regions where the DNA is repetitive/symmetrical.
What was the first single-gene disorder for which the mechanism of mutation was understood?
The first single-gene disorder was sickle cell disease.
What term describes cancer cells that have lost their specializations?
The term is dedifferentiation/dedifferentiated.
What is a passenger mutation?
A passenger mutation does not cause or propel a cancer’s growth and spread.
What are genes that normally prevent cell division called?
They are known as tumor suppressor genes.
What causes osteogenesis imperfecta?
It is caused by a mutation in a gene that encodes collagen.
What arrangement do two linked genes in a heterozygote have?
The genes are said to be in a cis arrangement.
What does genetic heterogeneity refer to?
Genetic heterogeneity refers to mutations in different genes that cause the same symptoms.
What does a missense mutation do?
A missense mutation causes sickle cell disease by altering the protein’s shape and affecting its gene copies.
How is a mitochondrial trait passed?
A mitochondrial trait is passed from mothers to sons.
What affects the phenotype in imprinting?
Imprinting affects the phenotype when one allele is imprinted and the other is activated.
What can cause mutation during meiosis?
Direct repeats can cause mutation when homologs duplicate during meiosis.
How are genes on the X chromosome expressed in human males?
In human males, genes on the X chromosome are expressed.
How many genes affect skin, hair, and eye color in humans?
There are more than 10 genes that affect skin, hair, and eye color in humans (nearly 170 genes).
Do people with light skin have the same number of melanocytes as those with dark skin?
People with light skin have about the same number of melanocytes as people with very dark skin.
What type of mutation changes GAA to UAA?
A mutation that changes the codon GAA to UAA is a nonsense mutation.
Where was the first narcolepsy gene discovered?
The first narcolepsy gene was discovered in dogs (canines).
What does GGG exhibit when consuming more cocaine for the same effect?
He is exhibiting tolerance.
What worsens myotonic dystrophy with each generation?
It worsens because of the increasing number of repeated long DNA sequences.
What do all cancers reflect at a general level?
All cancers reflect a defect in DNA repair and cell cycle regulation.
What do sporadic cancers result from?
Sporadic cancers result from somatic cells (somatic mutations).
What are traditional cancer treatments?
Traditional cancer treatments include surgery, chemotherapy, and radiation.
Why are mutations more likely to occur in repeated DNA sequences?
Because the bases in the strand can form base pairs by generating loops that interfere with transcription and enzyme repair.
What is a tautomer?
A tautomer is an alternate structure of a molecule.
What is the proportion of shared genes between a grandparent and grandchild?
The proportion is 25 percent.
What is a source of gamma radiation?
A source of gamma radiation is cesium isotope.
