Genetics Flashcards
What does a dihybrid cross show?
The inheritance of two through two generations. In a dihybrid cross the genes that determine the two characteristics are located on different pairs of homologous chromosomes. Each of these genes can have two or more alleles.
What does homozygous mean?
Having the same alleles for a particular characteristic.
What does a monohybrid cross show?
The inheritance of one through two generations.
What does mutation mean?
A change in the genetic composition of a cell.
What are gene mutations?
Chemical changes in the DNA of a cell.
What is a metabolic block?
The failure to bring about a normal enzyme conversion.
If a new born baby suffers a metabolic block they can develop a disease called phenylketonuria. What are the effects of this?
Phenylalanine concentration builds up within the body of the new born baby.
Phenylalanine is converted into toxic substances.
The toxic substances cause irreversible damage to the developing brain.
What are chromosome mutations caused by?
Change in the chromosome structure or the chromosome number of a cell.
What is a chromatid?
One of two daughter strands of a replicated chromosome.
What are genes?
A section of DNA which controls part of our cell’s chemistry.
What is non-disjunction?
Two homologous chromosomes, instead of separating, both go into the same gamete.
What happens as a result of non-disjunction?
Some gametes have two copies of a chromosome and others lack a copy.
What does a karyotype show?
The full set of chromosomes of an individual arranged in sequence.
What are mutagenic agents?
When certain chemicals and rays can increase the rate of frequency of mutation.
What is polyploidy?
Polyploidy is a condition in which an individual has sets of chromosomes greater than the normal diploid number.
