Biology 2 Flashcards
(25 cards)
the proportion of each phenotype in the real offspring of a genetic cross
Actual ratio
parents, the first generation and the second generation of offspring in a genetic cross
P,F1,F2
Gel electrophoresis
is a technique that can be used in DNA profiling
the differences between individuals in a population
variation
characteristics that show a wide range of values
continuous variation
the allele that will only be shown in the phenotype if two copies of it are inherited
recessive allele
a section of DNA on a chromosome, contains the instructions for a characteristic
gene
long thread-like structures made of DNA
chromosomes
a grid that shows the possible combinations of alleles that can result at fertilisation.
Punnet square
What does heterozygous mean.
when the two alleles an organism inherits are different
location of the genetic material in a cell
nucleus
the alleles an organism has for a characteristic
genotype
sex chromosomes in a female
XX
sex chromosomes in a male
XY
What are Alleles
different versions of a gene that contain different instructions for a characteristic
a diagram that displays the phenotypes of individuals in several generations of a family.
pedigree chart
The particular version of a characteristic seen in an individual.
phenotype
What does homozygous mean.
when the two alleles an organism inherits are identical
the allele that will mask the effect of a recessive allele
dominant allele
the proportion of each type of phenotype expected as the result of a genetic cross
Predicted ratio
male or female sex cell, contains only one set of genes
gamete
a genetic disorder where there is an extra copy of chromosome 21.
Downs syndrome
a picture of the chromosomes from one cell of a species
karyotype
characteristics that fall into separate categories
discrete variation
