1. Genetics in Agriculture
Agricultural Science I

2. At the completion of this unit, students will be able to:
Define genetics, and discuss its importance.
Identify and discuss the contents of a genome.
Distinguish heredity type, including genotype and phenotype.
Describe genetic trait expression and prediction.

3. Asexual Production
The production of young from only one parent
No gametes involved (egg and sperm)
Offspring are identical to parents
Sexual Reproduction
The production of young from two parents
Involves gametes (egg and sperm)
Offspring are similar to parents

4. Meiosis Similar events to mitosis (cell division)
Occurs only in testes and ovaries to produce egg and sperm cells.
Reduces the number of chromosomes to half the normal number.
One replication followed by two cell divisions.

5. Spermatogenesis Occurs in testes
Results in four equally sized sperm cells being produced

6. Oogenesis Occurs in ovaries Results in four different sized cells:
One egg cell
Three polar bodies

7. Definitions:
Fertilization: union of egg and sperm; restores normal chromosome number
Zygote: Fertilized egg
Dominant: Trait that shows in a cross between two true-breeding parents
Recessive: Trait hidden in a cross between two individuals

8. Definitions: Traits: characteristics that are inherited
Heredity: The passing of traits from parent to offspring
Genetics: The study of heredity and traits
Pollination: Transfer of pollen grains to the female reproductive organ in flowers