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/di
fference-between-dominance-and-
recessive#sthash.G8bYyllJ.dpuf