Dominant and recessive

Simple explanation suitable for 5th grade

1. Dominant and Recessive

2. Vocabulary 9. Dominant - an allele that produces the same phenotypic effect in heterozygotes and homozygotes. 10. Recessive- organism that has a recessive trait. 11. Dominant allele- produces the same phenotype either paired or identical or different.

3. 12. phenotype-the observable constitution of an organism 13. genotype- combination of alleles located on homologous chromosomes that determines a specific characteristic or trait.

4. DIFFERENCE BETWEEN DOMINANCE AND RECESSIVE

5. For an example: If mother has blue eyes and father has brown eyes, then the child will have either a copy of blue eyes or brown eyes.

6. Now here, the genes of brown eyes are dominating (BB) and genes for blue eyes are recessive (bb). Here the capital letter (B) shows dominance and small letter (b) shows recessive.

7. From the example we can conclude that the dominating gene expressed and children will have brown coloured eyes in F1-generation whereas in F2 generation there will be possibility of both blue and brown coloured eye children.

8. From the above example, we can conclude that the dominant gene has more capacity than recessive gene, to be expressed. But it doesn’t mean that if recessive gene is masked in F1 generation, is omitted from the generation.

9. It will reappear in F2 generation, after the process of self crossing (crossing amongst F1-generation). Here, the dominant genes can step by step passes to the future generations whereas the recessive genes will slowly disappear.

10. Reference: http ://www.biology.lifeeasy.org/2501/difference-between-dominance-and-recessive#sthash.G8bYyllJ.dpuf