Study Guide: Genetics
Terms:
Trait
Gregor Mendel
Alleles
Dominant
Phenotype
Dihybrid cross
Polygenic inheritance
Pedigree
Purebred
Genetics
Hybrids
Homozygous
Recessive
Genotype
Incomplete dominance
Gene locus
Chromosome theory of
inheritance
Principle of Independent
assortment
Cross-fertilization
Monohybrid cross
Heterozygous
Punnett square
Test cross
Codominance
Genetic linkage
Sex linked genes
1. Explain what the P generation, F1 generation, and F2 generation are.
2. What were Gregor Medels four hypotheses?
3. Explain the difference between homozygous and heterozygous alleles.
4. Explain the difference between a phenotype and a genotype.
5. Know what a punnet square is and be able to draw one for a monohybrid and dihybrid cross.
6. Identify the genotypes of the following rabbits. Black is dominant to white, and straight ears are
dominant to floppy ears.
A rabbit is homozygous dominant in color and is heterozygous for ears_____________________
A white rabbit with floppy ears_________________________
A rabbit is heterozygous for color and homozygous recessive for ears_____________________
A white rabbit with homozygous dominant ears_______________________
7. A man heterozygous for non-attached earlobes (Nn) can roll his tongue. A woman with attached
earlobes (nn) can roll her tongue. Assume both are heterozygous for the tongue-rolling trait (Rr)
What is the genotype of the mother? __________________
What is the genotype of the father? ___________________
Draw the Punnett square, and combine the gametes to produce offspring
What is the phenotypic ratio of these offspring? __________________
8. In pigs, mule hoof (fused hoof) is dominant (C), while cloven foot is recessive (c). Belted coat pattern
(S) is dominant to solid color (s) Draw a Punnett square showing a cross between two dihybrid pigs –
they both have the genotype CcSs.
What is the phenotypic ratio of the offspring? _____________
9. Explain the principle of Independent Assortment.
10. What are the exceptions to Mendel’s 4 hypothesis. Explain each.
11. Cross XBXb x XbY
What percent of male offspring are colorblind? ___________________
What percent of offspring are carriers of colorblindness? _________________
What percent of female offspring are colorblind? _____________________
12. Cross XBXb x XBY
What percent of male offspring are colorblind? ______________________
What percent of offspring are carriers f colorblindness? _____________________
What percent of female offspring are colorblind? _____________________
13. Lorax can have red, yellow, or orange fur. The allele that controls
this trait is INCOMPLETELY DOMINANT, where orange hair is caused
by the heterozygous condition. Show a "key" for the genotypes and
phenotypes of hair color.
Red_____________
Yellow____________
Orange____________
14. Lucy lorax has yellow hair she marries Larry lorax with orange hair what are the possible genotypic
ratio and phenotypes ratio of their children. Show the punnett square.
15. Linda lorax has red hair and marries lance lorax with yellow hair. What percent of their offspring will
have yellow hair__________, red hair_________, and orange hair_____________?
Show your punnett square.
16. A bird can have white feathers, blue feathers, and feathers with blue and white. This trait is
CODOMINANT. Make a key showing the genotypes using the phenotypes of feather color.
Blue_________
White__________
Blue/White_____________
17. A bird with blue/white feathers is crossed with a blue feather bird what are the genotypic and
phenotypic ratios. Show punnett square.
List all the different blood types for humans, be able to draw punnett squares using these blood types.
18. Explain genetic linkage.
19. Be able to read a pedigree.
What people are affected in each generation ______________________________?
Is the affected trait dominant or recessive___________________________
How many females did the generation 1 parents have______________________________?
Label the genotypes of everyone in the pedigree using GG, Gg, gg