How can an individual carry a defective gene but not exhibit the defective phenotype? Individuals carry two copies of gene instructions, and one dominant allele could mask the presence of a recessive defective allele Heterozygous individuals: can have greater fitness than homozygous individuals.
What is the difference between a phenotype and a gene?
Most genes come in alternative forms called: a) alleles. b) chromosomes. c) heterozygotes. d) gametes. e) homozygotes. alleles. A phenotype: a) does not reveal the heritability of traits. b) consists of the observable properties of an individual. c) does not include an organism's behavior. d) cannot change during the course of an organism's life.
How do you determine the phenotype of an organism?
The phenotype of an organism can best be determined by: a) true-breeding. b) a reciprocal cross. c) sequencing its genes. d) observing the organism. e) inbreeding.
When genetically based traits are inherited independently from each other?
When genetically based traits are inherited independently from each other, this is known as: a) Law of Segregation. b) Mendel's law of independent assortment. c) linkage. d) multi-allelism. e) pleitropy. Mendel's law of independent assortment.
What do DRD4 genotypes respond to a questionnaire?
Subjects in a study (with known DRD4 genotypes) responded to a questionnaire on temperament and character. Based on the graph shown above, what conclusion might you draw about an individual with two C alleles?
When a person inherits a recessive gene that is not expressed in the phenotype?
When a person inherits a recessive gene that is not expressed in the phenotype, that person is a carrier of the gene. Every person starts life as a single cell called a stem cell. The first two weeks of prenatal development are called the fetal period.
Why can't you always identify the genotype of an organism from its phenotype?
Due to dominance and recessiveness of alleles, an organism's traits do not always reveal its genetics. Therefore, geneticists distinguish between an organism's genetic makeup, called its genotype, and its physical traits, called its phenotype.
Can the individual carry an allele that is not expressed yes no?
However, an allele that is hidden, or not expressed by an organism, can still be passed on to that organism's offspring and expressed in a later generation.
What is it called if one gene does not completely mask the effect of its allele?
Incomplete dominance is when a dominant allele, or form of a gene, does not completely mask the effects of a recessive allele, and the organism's resulting physical appearance shows a blending of both alleles. It is also called semi-dominance or partial dominance.
How is it possible for an organism to have a recessive phenotype for a trait such as white flowers in pea plants?
Often, organisms will carry a dominant and a recessive allele of a gene. These organisms can be referred to as carriers of the recessive allele. For example, if a pea plant has a red flower-color allele and a white flower-color allele, then it is a carrier of the recessive white flower-color allele.
Can a person's genotype be determined by their phenotype?
No, a person's genotype cannot be determined solely by their phenotype as many genes in our genome do not get expressed.
Can individuals with the same genotype have different phenotypes?
The same genotype, when raised in different environments results in different phenotypes.
Why does an individual always have only two alleles for a given gene?
Despite multiple allelism, an individual will have only two alleles because an individual develops from a zygote which is the result of the fusion of sperm (carrying father set of(n)haploid chromosomes) and an egg (carrying mother set of haploid chromosomes). Sperm and an egg have only one gene (allele) for each trait.
How is phenotype expressed?
Phenotype is defined as an organism's expressed physical traits. Phenotype is determined by an individual's genotype and expressed genes, random genetic variation, and environmental influences. Examples of an organism's phenotype include traits such as color, height, size, shape, and behavior.
How does the phenotype appear when incompletely dominant alleles are present?
In incomplete dominance, the phenotype in a heterozygous individual is visibly less intense than that in an individual homozygous for the dominant allele, so that AA and Aa genotypes produce different phenotypes. Hence, the heterozygote (Aa) will have a phenotype intermediate between that of AA and aa individuals.
When one gene masks the effect of other gene then it is called?
A gene that masks the phenotypic effect of another gene is called an epistatic gene; the gene it subordinates is the hypostatic gene.
When more than one phenotype is influenced by the same gene it's called?
Pleiotropy (from Greek πλείων pleion, 'more', and τρόπος tropos, 'way') occurs when one gene influences two or more seemingly unrelated phenotypic traits. Such a gene that exhibits multiple phenotypic expression is called a pleiotropic gene.