• Categorized under Biology | Difference Between Dominant and Recessive Show Dominant vs Recessive Genetics is the science of heredity, genes, and the differences in living organisms. It is a biological discipline that deals with the structure and function of genes, their behavior and patterns of inheritance from the parents to the offspring. In the case of humans, as each individual is formed by the union of the egg and sperm cells of both parents, a diploid cell containing the necessary genetic materials to create him is developed. This genetic material is composed of chromosomes with individual genes or alleles containing specific traits. For each trait, an individual acquires two copies of genes or alleles, one from the mother and the other from the father. If the two alleles from both parents are similar, the offspring is homozygous, and if they are different, the offspring is heterozygous in which case the stronger of the two will show up in the offspring while the weaker one is masked. The allele or gene that shows up is called “dominant,” and the allele that is masked is called “recessive.” Recessive alleles or genes will only show up if the offspring inherits recessive copies of the trait from both parents. Dominant genes are usually the ones that are oftentimes observed in an offspring and passed down to subsequent generations while recessive genes will only show for a few generations and eventually disappear. Dominant genes are represented by capital letters and recessive genes are represented by small letters. There are three combinations of genotypes or alleles: AA (receives dominant traits from both parents), Aa (receives a dominant trait from one parent and a recessive trait from the other), and aa (receives recessive traits from both parents). Eye color is one example wherein dominant genes mask recessive genes. If one parent has brown eyes and the other blue, brown is the dominant color and blue is the recessive. In the case of an individual’s hair type, if both parents have straight hair, the offspring will surely have straight hair. If one parent has curly hair and the other straight hair, either the offspring gets a straight, curly, or wavy hair depending on the genetic makeup of the alleles of both parents. Summary: 1.An individual receives two
copies of each trait that he inherits from his parents, one from the mother and one from the father, with one of them dominant and the other recessive.
Search DifferenceBetween.net :Loading...  Cite Written by : Emelda M. and updated on 2011, October 27 Articles on DifferenceBetween.net are general information, and are not intended to substitute for professional advice. The information is "AS IS", "WITH ALL FAULTS". User assumes all risk of use, damage, or injury. You agree that we have no liability for any damages. Know what it means for a gene to be dominant Understand why dominance sometimes doesn’t matter for sex-linked genes Have you ever wondered why some people have blue or brown eyes? The coloring of the blue and brown eyes is an example of different versions of a gene. Different versions of a gene are called . Alleles can be considered dominant or recessive, with dominant being the trait that is observed or shown and recessive being the trait is not seen. Dominant alleles are seen as an uppercase of a letter; for example, B. Recessive alleles are seen as a lower case of a letter; b. In order for a person to show the dominant trait, one of the person’s parents must have the dominant trait (which is an uppercase letter). Remember that human cells carry 2 copies of each chromosome, one from the biological mother’s genes and one from the biological father’s genes. With that being said, there are 2 sets of alleles that can be dominant or recessive. If a person carries a set of alleles (both uppercase and lower case letter of the gene) then the person will show the dominant trait (being that there is an uppercase letter present). For example, the brown eye allele is dominant, B. You would need at least one copy of the brown eye allele (B) to have brown eyes. When you have two copies of the alleles that are both dominant, this is called . For example, if the dominant trait is red for flowers and another dominant trait is white, then the flower will have both red and white as the dominant traits are expressed equally. If a person carries two copies of the brown eye allele, since they are codominant, the person would have brown eyes. Recessive alleles are the genes that do not show the trait. If a person has one copy of the brown eye allele (dominant) and one copy of the blue eye allele (recessive) then that person is considered to be a of the blue eye allele, since they would have brown eyes but still have the blue eye trait that is not shown. Recessive alleles only show the traits if the person has 2 copies of the same alleles. This is considered being , having the same 2 copies of alleles. If a person has 2 copies of the blue eye allele (both recessive) then the person would have blue eyes. Image credit: Genome Research Limited Sex-linked genes are genes that are inhererited through the X chromosome. Remember that a biological female carries 2 sets of X chromosomes (XX) and a biological male carries one set of the X and one set of Y chromosomes (XY). If the offspring is a boy, the X chromosome comes from the mother and the Y comes from the father. If the offspring is a girl, one of the X chromosomes comes from the mother and the other X chromosome comes from the father. In some genetic diseases that are caused by sex-linked genes, for example , a color blindness trait, the allele for the disease is recessive. You can recall that recessive traits are only shown if they are homozygous (both copies of the alleles are recessive). For a female to have the disease, both of her X chromosomes must carry the recessive diseased copies of alleles. For a male to have a sex-linked gene, only one copy of the recessive sex-linked gene is needed for the male to have the disease. Dominance does not matter in sex-linked genes for XY males. If the mother is a carrier (unaffected but still have the affected trait), her offspring could be affected. Males are more likely to inherit a sex-linked gene as only one chromosome of a diseased trait is needed, whether the disease trait is dominant or recessive. You can see that sex-linked genes are by chance. Even though the father is affected with a dominant trait, only half of their offspring is affected, especially from the girls because they have to inherit a chromosome from the father. The male offspring was unaffected because they had already received a Y chromosome from the father so they got the non affected X chromosome form the mother. In this photo, the mother is affected with a dominant trait but only half of their offspring was able to be affected. The offsprings had a 50% chance of getting the affected trait. With an unaffected mother whose carrier, meaning the disease trait is recessive, only one of the offspring was affected and one is unaffected but a carrier. This is an example of how dominance genes does not matter as it depends on which X chromosome you can get and whether or not the set chromosomes you inherited contain the diseased trait being dominant or recessive. With males especially, they would only get a 50/50 chance of inheriting a non diseased trait, as they can only get the X chromosome from the mother. With females, they have a lower chance of getting a diseased trait as it depends on what chromosome she inherited from the mother whether its dominant or recessive and what X chromosome she inherited from her father. CC LICENSED CONTENT, PREVIOUSLY SHARED Whats the difference between dominant and recessive genes?What the difference between dominant and recessive genes? ANSWER: Dominant is always expressed when present. Recessive is only expressed when no dominant genes are present.
What are the differences between the dominant and recessive genes give an example of each?If a person receives dominant alleles from both parents (BB) she will have brown eyes. If she receives a dominant allele from one parent and a recessive gene from the other (Bb) she will also have brown eyes. But if she receives recessive alleles from both parents (bb), she will have blue eyes.
What is an example of dominant and recessive traits?In Humans. Many traits we observe in the people around us are examples of dominant and recessive traits. For example, having a straight hairline is recessive, while having a widow's peak (a V-shaped hairline near the forehead) is dominant.
What are dominant genes examples?Examples of Dominant Traits. Dark hair is dominant over blonde or red hair.. Curly hair is dominant over straight hair.. Baldness is a dominant trait.. Having a widow's peak (a V-shaped hairline) is dominant over having a straight hairline.. Freckles, cleft chin and dimples are all examples of a dominant trait.. |
