Question

_Date trait as 1 ol for the Name Genetics Practice Problems #2 - Writing Alleles Period Directions: Using the data in Table 1. write the enotype that correspond phenotype descriptions "e the genotype that corresponds to the em heig Symbol Round Table 1: Mendel's Traits and Symbols for Pea Plants Traits Dominant Allele Seed Shape I Symbol Recessive Allele Seed Color R Wrinkled Green Seed Coat Color White Pod Shape Constricted Pod Color Green Yellow Stem Height Tall Short Flower Position Axial Terminal Yellow Colored Smooth + oo a Phenotype Genotype Phenotype Genotype 1. Heterozygous for height 16. Constricted pod 2. Homozygous dominant for seed shape 17. Short height 3. Heterozygous colored seed coat 18. Green seed color 4. Homozygous green pod 19. Terminal flowers 5. Homozygous short 20. Pure wrinkled 6. Homozygous tall 21. Hybrid tall 7. Homozygous axial 22. Pure round 8. Homozygous terminal 23. Yellow seed pod 9. Heterozygous flower position 24. Hybrid smooth 10. Heterozygous seed color 25. Pure smooth pod 11. Homozygous smooth pod 26. Hybrid pod color 12. Homozygous constricted pod 27. White seed coat 13. Homozygous recessive for seed coat color 28. Wrinkled seed 14. Heterozygous for pod color 29. Pure colored seed coat 15. Homozygous round seed 30. Hybrid flower position

Answer 1

Ans)genotype is the genetic composition. That is the composition of the gene pair. Like TT is genotype.

Phenotype is the trait expressed, which is seen outside. So TT genotype will make the plant tall. The trait tall can be seen so it is the phenotype.

Now if the genotype is Tt the phenotype will still be tall as the dominant gene is T it gets expressed over t.

homozygous means both the alles in the pair are same. That is TT for tall or tt for short . Both alleles are for the tall trait. Which is T or for the short trait which is t.

Heterozygous or hybrid means both alleles are different.

So for example Tt is heterozygous because T is allele for tall and t is allele for short trait.

When recessive and dominant alleles are given. For the plant to be tall only one allele for tall trait that is T is enough for the trait to dominate.

So if the genotype is Tt. The tall trait dominates because T is the dominant allele and the plant will be tall.

But if a plant is short. The recessive allele should be in pair. That is tt should be the genotype. In case a T allele occurs, the T would dominate and the plant would be tall.

So for the plant to be tall atleast one allele for tall T should be present in the gene pair.

So TT is pure tall or say homozygous tall

Tt is heterozygous or hybrid tall.

In both these cases plant will be tall as atleast one T is present.

If the genotype is tt. The plant will be short because recessive alleles need to be in pair to be expressed.

Same goes for round and wrinkled seeds.

Round ( R) is dominant over (w) wrinkled.

So the plant has to be either RR homozygous dominant or Rr heterozygous dominant to be round. And rr that is homozygous for the plant to be short. As the R gene for round dominates over r gene for wrinkled so presence of even one R in allele pair will make the seed round as dominant gene suppresses the recessive gene to be expressed.

Now answers.

1 Tt

2 RR

3 Cc

4 GG

5 tt

6 TT

7 AA

8 aa

9 Aa

10 Yy

11 SS

12 ss

13 cc

14 Gg

15 RR

16 Cc

17 tt

18 yy

19 aa

20 rr

21 Tt

22 RR

23 gg

24 Ss

25 SS

26 Gg

27 cc

28 rr

29 Cc

30 Aa

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