What is dominant?
Dominant traits are genetic characteristics that are expressed when an individual has at least one copy of the dominant allele. These traits mask the expression of recessive alleles. An individual only needs to inherit one copy of the dominant allele from either parent to exhibit the dominant trait.
Examples of dominant traits:
1. Brown eyes
2. Curly hair
3. Tongue rolling ability
4. Dimples
5. Freckles
6. Broad lips
7. Widow’s peak hairline
8. Cleft chin
9. Unattached earlobes
10. ABO blood type (A and B)
Uses of dominant traits:
Dominant traits can be used in various fields such as forensic science, paternity testing, and genetic counseling. In forensic science, dominant traits can help identify suspects based on physical characteristics. Paternity testing uses dominant traits to determine the likelihood of a genetic relationship between individuals. Genetic counselors can use knowledge of dominant traits to predict the likelihood of specific traits being inherited by a child.
What are recessive traits?
Recessive traits are genetic characteristics that are only expressed when an individual has two copies of the recessive allele. An individual must inherit one copy of the recessive allele from each parent to exhibit the recessive trait. Recessive traits are often masked by dominant traits.
Examples of recessive traits:
1. Blue or green eyes
2. Straight hair
3. Inability to roll the tongue
4. No dimples
5. No freckles
6. Thin lips
7. Straight hairline
8. No cleft chin
9. Attached earlobes
10. O blood type
Differences Table:
| Difference Area | Dominant traits | Recessive traits |
|---|---|---|
| Expression | Expressed with only one copy of the dominant allele | Expressed with two copies of the recessive allele |
| Masking | Masks the expression of recessive alleles | Masked by dominant alleles |
| Inheritance | Can be inherited from one parent | Must be inherited from both parents |
| Frequency | More common in the population | Less common in the population |
| Traits | Brown eyes, curly hair, etc. | Blue or green eyes, straight hair, etc. |
| Genetic Variation | Less genetic variation | More genetic variation |
| Dominance | Exhibits dominance over recessive traits | Exhibited only when no dominant allele is present |
| Inheritance Risk | Can increase the risk of inheriting certain conditions or diseases | Less likely to increase the risk of inheriting certain conditions or diseases |
| Mendelian Laws | Follows Mendelian laws of inheritance | Follows Mendelian laws of inheritance |
| Expression Pattern | Always expressed in presence of dominant allele | Only expressed in the absence of dominant allele |
Conclusion:
In summary, dominant traits are expressed with at least one copy of the dominant allele, mask the expression of recessive alleles, and can be inherited from one parent. On the other hand, recessive traits require two copies of the recessive allele to be expressed, are masked by dominant traits, and must be inherited from both parents. Dominant traits are more common in the population and exhibit dominance over recessive traits. They can also increase the risk of inheriting certain conditions or diseases.
Knowledge Check:
1. True or False: Dominant traits require two copies of the dominant allele to be expressed.
2. What type of traits are masked by dominant traits?
3. Can recessive traits be inherited from one parent?
4. What is the frequency of recessive traits in the population?
5. Name one example of a recessive trait related to eye color.
6. True or False: Dominant traits have more genetic variation than recessive traits.
7. How are dominant traits inherited?
8. Do recessive traits increase the risk of inheriting certain conditions or diseases?
9. True or False: Dominant and recessive traits both follow Mendelian laws of inheritance.
10. When are recessive traits expressed in the presence of dominant alleles?
Answers:
1. False
2. Recessive traits
3. No, recessive traits must be inherited from both parents.
4. Less common in the population
5. Blue or green eyes
6. False
7. Dominant traits can be inherited from one parent.
8. Less likely to increase the risk of inheriting certain conditions or diseases.
9. True
10. Recessive traits are only expressed in the absence of dominant alleles.
Related Topics:
– Punnett Squares and the Inheritance of Traits
– Genetic Disorders Associated with Dominant and Recessive Traits
– The Role of Genes in Determining Physical Characteristics
