Biological Plant Science
Unit 5 Review – Plant Genetics and Heritability
5.1 Define Terms
Match the following terms with their BEST definition listed below:
A. F1 hybrid
B. genotype
C. heritability
D. heteroyzygous
E. homozygous
F. hybrid vigor (heterosis)
G. phenotype
H. Punnett Square
I. selective breeding
_____ 1. The portion of the difference in animals that is transmitted from parent to offspring.
_____2. Having identical alleles at one or more loci and therefore producing identical gametes.
_____3. A common method of predicting the genotypes and phenotypes of offspring using a matrix.
_____4. The genetic makeup.
_____5. Choosing plants for breeding based on their desired qualities or fitness.
_____6. Having different alleles for a single trait and therefore producing identical gametes.
_____7. An offspring of two parents in which the offspring is sterile.
_____8. The physical appearance of an organism.
_____9. The act of the offspring outperforming the parents due to gene combination.
Match the following terms with the BEST definition listed below:
A. Allele
B. chromosome
C. deoxyribonucleic acid (DNA)
D. dominant gene
E. gene
F. hormone
G. incomplete dominance
H. mutation
I. recessive gene
_____10. That part of a cell that contains information about genetic makeup and transmits that
information to offspring.
_____11. A chemical messenger substance produced in one location of an organism and carried to
another where it has a specific effect(s).
_____12. An accident of heredity in which an offspring has different characteristics than the genetic
code intended.
_____13. Causes a certain characteristic to be expressed; present in offspring.
_____14. The specific determiner of heredity.
_____15. A genetic protein-like nucleic acid in plant and animal genes and chromosomes that
controls inheritance.
_____16. When either gene is dominant, both genes are expressed (example: red and white cattle
produced a roan colored calf)
_____17. The character will be masked if either parent has a dominant gene; will only be expressed
if the alleles from both parents are the same (and not dominant).
_____18. Matching genes on homologous chromosomes.
5.2 Discuss the role and importance of genetics and heritability in the biological plant sciences
19. Briefly explain the principle of dominance:
20. Briefly explain how the purpose of the Punnett Square:
For each of the following crosses, use a Punnett Square to predict the possible outcomes:
21. Tall heterozygous plant (Tt) with a Tall heterozygous plant (Tt):
22. Tall homozygous plant (TT) with a Tall heterozygous plant (Tt):
23. Tall heterozygous plant (Tt) with a Short plant (tt):
5.3 Illustrate the importance of the various plant breeding schemes
24. Briefly explain the purpose of selective breeding:
25. Briefly explain the purpose of cross-pollination:
26. Briefly explain the purpose of hand pollination:
5.4 Explain how genetic principles are used to improve agricultural production
27. Briefly explain how grafting is beneficial in preserving genetic material:
28. Briefly explain why hybrid varieties are typically preferred over purebred varieties: