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No Cla t fo ssr r o Us om e
101 KEY TERMS AND IDEAS: Did You Get It?
PR E V ON IEW LY
1. Test your vocabulary by matching each term to its definition, as identified by its preceding letter code. A Having two homologous copies of each chromosome (2N), usually one from the mother and one from the father.
alleles
diploid
B Allele that will only express its trait in the absence of the dominant allele.
dominant
C Genetic cross between two individuals that differ in one trait of particular interest.
genotype
D Sequences of DNA occupying the same gene locus (position) on different, but homologous, chromosomes.
meiosis
E Observable characteristics in an organism.
monohybrid cross
F The allele combination of an organism.
phenotype
G The process of double nuclear division (reduction division) to produce four nuclei, each containing half the original number of chromosomes (haploid).
Punnett square
H A graphical way of illustrating the outcome of a cross.
recessive
I Allele that expresses its trait irrespective of the other allele.
2. The following dihybrid cross shows the inheritance of colour and shape in pea seeds. Yellow (Y) is dominant over green (y) and a round shape (R) is dominant over the wrinkled (r) form.
(a) Describe the appearance (phenotype) of pea seeds with the genotype YyRr:
(b) Complete the Punnett square below when two seeds with the YyRr genotype are crossed. Indicate the number of each phenotype in the boxes on the right. Female gametes
Yellow-round
Green-round
Yellow-wrinkled
(c) What type of inheritance pattern is this?
No Cla t fo ssr r o Us om e
Male gametes
Green-wrinkled
3. An original DNA sequence is shown right: GCG TGA TTT GTA GGC GCT CTG
For each of the following DNA mutations, state the type of mutation that has occurred:
(a) GCG TGT TTG TAG GCG CTC TG
(b) GCG TGA TTT GTA AGG CGC TCT G
(c) GCG TGA TTT GGA GGC GCT CTG
TEST CIE2.indb 128
Š 2016 BIOZONE International ISBN: 978-1-927309-32-2 Photocopying Prohibited
4/01/16 4:41 pm