Biology 30 Module 6 Lesson 1 Key Terms Quiz

1. What does it mean for a trait to be dominant?

Dominant traits are always physically stronger than recessive traits.

A dominant trait will always express itself in an organism whether it is partnered with a different (recessive) trait or with another dominant partner.
For example: The tallness trait in peas can be recognized as "A" which is dominant and the recessive shortness can be recognized as "a" "AA" will result in a tall pea as will "Aa"

An organism can have multiple dominant traits at the same time.

A dominant trait will only express itself if it is partnered with another dominant trait.

In genetics, dominance refers to the relationship between alleles of a gene. A dominant trait will be expressed in an organism even if it is partnered with a recessive trait. It does not necessarily mean the trait is physically stronger or that an organism can have multiple dominant traits simultaneously.

Explanation

In genetics, dominance refers to the relationship between alleles of a gene. A dominant trait will be expressed in an organism even if it is partnered with a recessive trait. It does not necessarily mean the trait is physically stronger or that an organism can have multiple dominant traits simultaneously.

2. What is a recessive trait?

A recessive trait will not express itself if partnered with a dominant trait, however, if partnered with another recessive trait-it will appear in the organism.
For example: The tallness trait in peas can be recognized as "A" and the shortness can be recognized as "a""Aa" will result in a tall pea, but "aa" will result in a short pea.

Genes only come in dominant forms, recessive traits do not exist.

A recessive trait will always express itself, regardless of the pairing.

A dominant trait always expresses itself.

A recessive trait manifests only when paired with another recessive trait. It remains hidden if paired with a dominant trait. This phenomenon can be observed in genetic crosses, like in the example of tallness and shortness traits in peas.

Explanation

A recessive trait manifests only when paired with another recessive trait. It remains hidden if paired with a dominant trait. This phenomenon can be observed in genetic crosses, like in the example of tallness and shortness traits in peas.

3. What is complete dominance?

The fact that a recessive allele will always express itself over a dominant allele.

The concept that alleles on different genes interact to determine a single trait.

The idea that multiple genes work together to determine a single trait.

The fact that a dominant allele (different forms of the same gene) will always express itself over a recessive allele. An organism possessing one recessive and one dominant allele will have the same physical characteristics as an organism with two dominant alleles.
For example: A pea possessing one dominant tallness trait and one recessive shortness trait would become a tall pea, just the same as it would if it had two dominant tallness traits.

Complete dominance refers to the scenario where a dominant allele will always mask the presence of a recessive allele in an organism's phenotype, resulting in the expression of the dominant trait.

Explanation

Complete dominance refers to the scenario where a dominant allele will always mask the presence of a recessive allele in an organism's phenotype, resulting in the expression of the dominant trait.

4. What is the Law of Segregation?

The Law of Segregation states that gene factors do not segregate during the formation of gametes.

The Law of Segregation was proposed by Darwin, not Mendel.

The Law of Segregation was Mendal's first law of inheritance. It stated that all individual organisms possessed two copies of each gene factor and that these factors "segregate" randomly during the formation of gametes. Finally, after the separation of these factors, each gamete receives one copy of each gene.

The Law of Segregation dictates that only one copy of each gene factor is present in individual organisms.

The Law of Segregation, proposed by Mendel, explains how gene factors segregate and are randomly distributed during gamete formation, ensuring genetic diversity in offspring.

Explanation

The Law of Segregation, proposed by Mendel, explains how gene factors segregate and are randomly distributed during gamete formation, ensuring genetic diversity in offspring.

5. What is a Genotype?

The environmental conditions that impact an organism

The total number of chromosomes in an organism

A Genotype is the combination of alleles that produced any given trait.
For example: According to Mendal's system the allele for wrinkled seeds is referred to as "r" and the allele for round seeds is referred to as "R"Each pea plant could potentially possess the GENOTYPES "RR" "Rr" or "rr"

The physical appearance of an organism

The Genotype refers to the genetic makeup of an organism, specifically the combination of alleles that determine a particular trait, not the physical appearance, number of chromosomes, or environmental factors affecting the organism.

Explanation

The Genotype refers to the genetic makeup of an organism, specifically the combination of alleles that determine a particular trait, not the physical appearance, number of chromosomes, or environmental factors affecting the organism.

6. What is a phenotype?

The Phenotype is the environment in which an organism lives.

The Phenotype is the study of inherited traits in organisms.

The Phenotype is the genetic makeup of an organism.

The Phenotype is the outward observable expression of the trait that is created by an organisms Genotype.
For example: According to Mendals system of "R" referring to round seeds and "r" referring to wrinkled seeds, the production the Genotype "RR" would result in the PHENOTYPE of round seeds.

The correct definition of a phenotype is the outward observable expression of a trait influenced by an organism's genotype. It is not the genetic makeup of an organism, the study of inherited traits, or the environment in which an organism lives.

Explanation

The correct definition of a phenotype is the outward observable expression of a trait influenced by an organism's genotype. It is not the genetic makeup of an organism, the study of inherited traits, or the environment in which an organism lives.

7. What does the term 'homozygous' refer to?

Possessing only dominant alleles

Having two different alleles in genotype

Homozygous is the term used to describe an individual that possesses a genotype consisting of two identical alleles
For example: "RR" or "rr"

Referring to a genetic mutation

8. What does the term 'heterozygous' mean?

Heterozygous is the term used to describe an individual that possesses a genotype consisting of two different alleles
For example: "Rr"

Monohybrid is the term used to describe a genetic cross involving one trait.

Phenotype is the physical expression of genes.

Homozygous is the term used to describe an individual that possesses a genotype consisting of two identical alleles.

Heterozygous refers to having two different alleles, while homozygous means having two identical alleles. Monohybrid and phenotype are related concepts but not the direct definition of heterozygous.

Explanation

Heterozygous refers to having two different alleles, while homozygous means having two identical alleles. Monohybrid and phenotype are related concepts but not the direct definition of heterozygous.

9. What is a Punnet Square?

A Punnet Square is a fairly simply table developed by British geneticist Reginald Punnet. The Punnet Square is used to clearly show all possible combinations of alleles.

A Punnet Square is a musical instrument used in traditional British folk music.

A Punnet Square is a term used in architecture to describe a specific type of window design.

A Punnet Square is a type of fruit grown in British gardens.

A Punnet Square is a tool used in genetics to predict the probability of certain traits being passed on to offspring. It is named after Reginald Punnet, who developed this concept in the early 20th century.

Explanation

A Punnet Square is a tool used in genetics to predict the probability of certain traits being passed on to offspring. It is named after Reginald Punnet, who developed this concept in the early 20th century.

10. What is a test cross?

A test cross is a test done by geneticists to find out if an organisms phenotype is heterozygous or homozygous. A test cross is done between an organism with an unknown genotype and homozygous recessive organism, and the offspring is further studied.
For example: The condition "waltzer" is a recessive condition that interferes with balance in mice. In order to test mice who appear normal but may possess a recessive gene for the defect, geneticists would do a test cross. If the mouse being tested was heterozygous, half of its offspring would have the waltzer condition.

A test cross is a type of test to determine the color of an organism's fur.

A test cross is a test to determine the weight of an organism.

A test cross is a test to identify the gender of an organism.

A test cross is specifically used to determine genotype characteristics, not physical attributes such as fur color, weight, or gender.

Explanation

A test cross is specifically used to determine genotype characteristics, not physical attributes such as fur color, weight, or gender.

11. What is a dihybrid cross?

A Dihybrid Cross is the breeding or "crossing" of two individuals that possess two different traits.
For example: Mendal crossed homozygous tall green plants (TTGG) with homozygous short yellow plants (ttgg) resulting in offspring that were heterozygous for both traits (TtGg)

A dihybrid cross only considers one trait in the offspring.

A dihybrid cross results in offspring that are always homozygous for both traits.

A dihybrid cross involves crossing two individuals with the same traits.

A dihybrid cross specifically involves the crossing of individuals with two different traits, not the same traits. It considers both traits in the offspring, not just one. The offspring resulting from a dihybrid cross are typically heterozygous for both traits, not homozygous.

Explanation

A dihybrid cross specifically involves the crossing of individuals with two different traits, not the same traits. It considers both traits in the offspring, not just one. The offspring resulting from a dihybrid cross are typically heterozygous for both traits, not homozygous.

12. What is Incomplete Dominance?

Incomplete Dominance always results in a blending of traits.

Incomplete Dominance occurs when one gene completely conceals the other.

Incomplete Dominance only happens in animals, not plants.

Incomplete Dominance is used to describe the occurrence in which neither of the two alleles for the same gene can completely conceal the other.
For example: A flower known as the "four o'clock plant is a cross between a true-breeding red flower and a true-breeding white flower which produces a pink flower.

Incomplete Dominance is a genetic concept where neither allele is dominant over the other, leading to a unique expression of both alleles. It does not involve complete concealment of one allele, is not limited to animals, and doesn't always result in a perfect blend of traits.

Explanation

Incomplete Dominance is a genetic concept where neither allele is dominant over the other, leading to a unique expression of both alleles. It does not involve complete concealment of one allele, is not limited to animals, and doesn't always result in a perfect blend of traits.

13. What is True Breeding?

A True Breeding organism is one that possesses homozygous traits and thus produces further homozygous organisms.

A True Breeding organism is a hybrid plant with unpredictable traits.

True Breeding refers to organisms that have a mix of homozygous and heterozygous traits.

True Breeding is a term used to describe organisms that can only reproduce through asexual methods.

True Breeding refers to organisms that have homozygous traits and can consistently pass down those traits to offspring.

Explanation

True Breeding refers to organisms that have homozygous traits and can consistently pass down those traits to offspring.