Question

1. is the physical trait that is expressed in an individual.
2. are the different forms of a gene for any given trait.
3. for each trait, there are allele possibilities.
4. when the expression of one allele is masked by the presence of another, it is said to be
5. when an allele masks the presence of another allele, it is said to be
6. when both alleles of a parent or offspring are identical, one is said to be
7. a heterozygous genotype is when the alleles present are, such as bb.
8. it is proper to put the allele before a recessive allele when determining the genotype of the offspring in a punnett square.
9. for an offspring to a recessive trait, both parents must have at least one allele in their genotype.

a punnett square is a diagram that is used to predict an outcome of a particular cross or breeding experiment. it is named after reginald c. punnett who devised the approach. the diagram is used by biologists to determine the probability of an offspring having a particular genotype
for the following pairs of traits, conduct a monohybrid cross to determine the genotype and phenotype of the offspring.
dominant trait: b (brown hair)
recessive trait: b (blond hair)
possible genotypes: b b, bb and b b
possible phenotypes: 75% brown hair, 25% blond hair

Explanation:

• Question 6: The physical trait expressed in an individual is called the phenotype. It is what we can observe, like eye color or hair color.
• Question 7: Alleles are the different forms of a gene for any given trait. For example, for the eye - color gene, there could be a "brown - eye" allele and a "blue - eye" allele.
• Question 8: For each trait, there are two allele possibilities. This is because an organism inherits one allele from each parent.
• Question 9: When the expression of one allele is masked by the presence of another, it is said to be recessive. Recessive alleles are only expressed when there are two copies of them (in a diploid organism).
• Question 10: When an allele masks the presence of another allele, it is said to be dominant. A dominant allele will be expressed even if there is only one copy of it.
• Question 11: When both alleles of a parent or offspring are identical, one is said to be homozygous. For example, \(BB\) (homozygous dominant) or \(bb\) (homozygous recessive).
• Question 12: A heterozygous genotype is when the alleles present are different, such as \(Bb\). In this case, there is one dominant and one recessive allele.
• Question 13: It is proper to put the dominant allele before a recessive allele when determining the genotype of the offspring in a Punnett square. This is a standard convention for writing genotypes.
• Question 14: For an offspring to express a recessive trait, both parents must have at least one recessive allele in their genotype. If a parent has only dominant alleles (\(BB\)), they can only pass on dominant alleles to their offspring.

Answer:

1. Phenotype
2. Alleles
3. two
4. recessive
5. dominant
6. homozygous
7. different
8. dominant
9. express, recessive