Not necessarily. I think the dominant genes are more common, but there are lot of exceptions out there. For example, having six fingers in humans is a dominant gene, but it isn't all that common.
If the recessive genotype is selected for more often than the dominant genotype, the recessive allele will become more common than the dominant allele in the gene pool.
dominant-appears in first generation recessive-seems to dissapear
In simple Mendelian genetics, there may be several alleles (variations) for a given trait. since organisms generally have two pairs of chromosomes, they have two alleles. A dominant allele is one that when it is present, always shows itself. A recessive allele only shows when there are two copies of the recessive allele. For example, suppose brown hair is dominant and black hair is recessive. If there are any copies of the brown hair allele, the person's hair will be brown. A person's hair will be black only if they have two copies of the black hair allele. In reality, genetics is much more complicated than simply dominant and recessive as many genes may influence one trait.
A dominant gene will be expressed if paired with a recessive gene or with a dominant gene for the same trait. For example, the trait for brown eyes (BB) is dominant over blue eyes (bb) - thus an offspring Bb will express brown eyes, just as BB.
recessive alleles get masked to show the difference in a dominant gene and a recessive gene. the dominate genes masks the recessive genes to show that the dominate gene is more dominate or more likely to be the outcome than the reccessive gene but the masked gene is not always recessive.
Dominant allele because its more likely to be received by the next generation.
If the recessive genotype is selected for more often than the dominant genotype, the recessive allele will become more common than the dominant allele in the gene pool.
YES ALWAYS!!! Even if you have for example, Aa (A being the dominant allele and a being the recessive allele) that trait will always be dominant!
dominant-appears in first generation recessive-seems to dissapear
There are no such things as dominant and recessive genes. There are only dominant and recessive alleles. Dominant alleles are parts of a gene that present its features over the recessive allele, which is the one that is always masked by the dominant allele. The recessive allele's trait only shows if both of the alleles in a trait are recessive.
In genetics, each organism will typically have 2 alleles for each trait. For a trait such as hair color, you might have an allele for red hair from your dad and an allele for brown hair from your mom. The trait for brown hair happens to be dominant to the trait for red hair so you would show the allele for brown hair. (In other words, you would have brown hair.)
A defective allele is more likely to be eliminated from a population if it is dominant. This is because it is immediately exposed to the effects of selection, as only one copy of a dominant allele is needed for it's characteristic to be developed. If an allele is recessive it can survive in a population as it is 'hidden' from selection by the presence of the corresponding dominant allele. It will only beexposed to selectionif an individual inherits the recessive allele from both parents. If the recessive allele is rare, the chances of two individuals with the allele mating could be quite small. In this way a defective recesssive allele could survive at low levels in a population.
A lethal dominant gene prohibits the organism from reproducing irregardless of the paired gene, so it is removed from the gene pool as soon as it appears. A lethal recessive gene, on the other hand, does not prevent reproduction unless it is paired with another lethal recessive, so it may be passed down through many generations before becoming paired and preventing reproduction.
No. For example, the six-finger allele is dominant over the five-finger allele in humans, yet you see almost nobody with six fingers, because it has such a low frequency. It all depends on the allele frequency in a given population.
In simple Mendelian genetics, there may be several alleles (variations) for a given trait. since organisms generally have two pairs of chromosomes, they have two alleles. A dominant allele is one that when it is present, always shows itself. A recessive allele only shows when there are two copies of the recessive allele. For example, suppose brown hair is dominant and black hair is recessive. If there are any copies of the brown hair allele, the person's hair will be brown. A person's hair will be black only if they have two copies of the black hair allele. In reality, genetics is much more complicated than simply dominant and recessive as many genes may influence one trait.
A dominant gene will be expressed if paired with a recessive gene or with a dominant gene for the same trait. For example, the trait for brown eyes (BB) is dominant over blue eyes (bb) - thus an offspring Bb will express brown eyes, just as BB.
heterozygous recessive