chapter 6 pt 2 study guide Flashcards
What term is given to the specific location of genes on a chromosome?
locus
What are alternative forms of a gene called?
allele
How many alleles do cells have for each gene?
two
Which type of allele is expressed when 2 different alleles or 2 dominant alleles are present on a chromosome?
Dominant
Which type of allele is expressed when 2 copies of a recessive allele are present on a chromosome?
recessive
What is commonly done by scientists while studying genetics?
Focusing on a single trait or set of traits
esides genotype, what also interacts with genes and affects their expression?
The environment
hat was the profession of R.C. Punnett?
Poultry geneticist
What type of system did Punnett develop for predicting all possible genotypes resulting from a genetic cross?
grid
By counting the number of squares in a genetic combination, what can be figured concerning genotypes?
Ratio of
genotypes in that generation
What process restores the diploid number in offspring?
fertilization
List the three types of monohybrid crosses.
Homozygous x homozygous,
heterozygous x heterozygous,
and heterozygous x
homozygous
List the three types of monohybrid crosses.
Homozygous x homozygous,
heterozygous x heterozygous,
and heterozygous x
homozygous
What type of phenotype must an organism have in order for a testcross to be necessary?
Recessive phenotype
What was the phenotypic ratio that Gregor Mendel consistently obtained in the second generation of breeding?
9:3:3:1