Inheritance test 6

A pleiotropic gene isn't necessarily linked to the Pliocene era or exclusively expressed in primitive plants.

It's not accurate to say that it only regulates a trait in tandem with other genes.

In fact, a pleiotropic gene is known to control numerous characteristics in an individual.

Based on these points, the correct answer is C, "It regulates multiple traits in an individual".

The law of dominance doesn't directly apply to the concept of gametes not being hybrid.

Neither does the law of independent assortment nor the law of random fertilization speak to the purity of gametes.

The law of segregation, on the other hand, stipulates that alleles separate during gamete formation, resulting in pure gametes.

Thus, the most fitting answer is C, "Law of segregation".

Autosomal dominant and recessive traits aren't specifically passed from father to son, but can be inherited from either parent.

X-linked traits aren't directly transmitted from father to son.

However, Y-linked traits move from father to son as the Y chromosome is received by the son.

Therefore, the correct answer is D, "Y-linked".

The human sex-determining system isn't XO-XX or ZZ-ZW.

Neither is it 'None of the above'.

Humans are known to possess the XY-XX sex determining system, where the male's sperm determines the sex of the child.

Hence, the correct answer is B, "XY-XX".

A dominant trait suggests an allele that overshadows the recessive one but does not imply identical alleles.

Hybrid indicates a combination of different genes, thus is not suitable for matching alleles.

Heterozygous refers to a pair of genes where one is dominant and the other recessive, which is not the case here.

Homozygous, however, describes an organism that has identical alleles for a trait. Therefore, the correct answer is D, "Homozygous".

While cytoplasmic effects, nutrition, mutations, and linkages can influence phenotype, they are not the fundamental determinants.

Environmental changes and sexual dimorphism are also not the primary drivers of phenotype.

Genotype and environmental interactions directly play a role in defining an organism's phenotype.

Thus, the correct answer is C, "Genotype and environment interactions".

Codominant alleles both express themselves, which is not the case here.

Supplementary and complementary alleles suggest a relationship of support or completion, rather than suppression.

A recessive allele is one that cannot express its effect in the presence of a dominant allele.

Therefore, the correct answer is D, "Recessive".

Hermaproditic flowers, like those found on the pea plants, enabled Mendel to control the reproduction process, contributing to his accurate results.

The sharply distinct traits of the pea plant further simplified Mendel's process of observing changes across generations.

The ease of self-fertilization further facilitated Mendel's control over the breeding process.

Given all these factors, the correct answer is D, "All of the above".

Though Lamarck, Darwin, and De-varies have all made significant contributions to the field of genetics, they did not perform the renowned experiments on the pea plant.

It was Gregor Mendel who conducted these experiments, meticulously studying around 29,000 pea plants.

Thus, the correct answer is D, "Mendel".

A Punnett Square does not show the DNA sequence, number of chromosomes, or the letters of a sequence in its offspring.

Instead, it visually demonstrates the possible combinations of alleles, or genotypes, that could result from a genetic cross.

Hence, the accurate answer is A, "Genotypes".

Mendel chose a plant species for his experiments that had distinguishable characteristic traits and was easy to grow and self-pollinate.

Pisum album, Oryza sativa, and Oryza orientalis do not fit these criteria.

The garden pea, Pisum sativum, was the perfect candidate for Mendel's work.

Consequently, the correct answer is A, "Pisum sativum".

Blood groups in humans illustrate various principles of genetics.

IAIO and IBIO relations show Dominance and recessive relationship, while IAIB shows Co-dominance.

IA, IB, and IO represent three different allelic forms of a gene, demonstrating the concept of Multiple alleles.

Therefore, the correct answer is B, "I, II, and III".

When a trait presents more than two possible phenotypes, it is not due to Codominance, Pseudo dominance, or Incomplete dominance.

This occurrence is a result of the effect of Multiple alleles, which inhabit the same chromosome locus and influence the same character.

Therefore, the correct answer is D, "Multiple alleles".

Mendel's law of independent assortment states that genes for different traits assort independently of one another in the formation of gametes.

This law would contradict the concept of linkage, where genes on the same chromosome are inherited together.

Linkage, which depends on the distance between genes on the same chromosome, would result in more parental combinations, challenging the law of independent assortment.

A monohybrid cross refers to a mating event between two organisms that are heterozygous for a trait.

In other words, it occurs when parents who differ in one characteristic breed.

Mendel conducted numerous monohybrid crosses, examining one characteristic at a time.

Therefore, the correct answer is B, "Monohybrid".

Alleles are variants or versions of a gene that can produce different phenotypic outcomes.

They are not true breeding homozygotes, heterozygous organisms, or different phenotypes.

Instead, they are different molecular forms of a gene that may result in different traits.

Therefore, the correct answer is B, "Different molecular forms of a gene".

Mendel, the father of genetics, was not aware of the concept of linkage, where genes located on the same chromosome tend to be inherited together.

This phenomenon was later discovered by Bateson and Punnet in 1906 in Sweet Pea (Lathyrus odoratus).

Thus, the correct answer is A, "Linkage".

Haemophilia is a serious genetic disorder that is more common in males than in females.

The gene responsible for this condition is recessive and is located on the X-chromosome, making it an X-linked disease.

Individuals with this gene lack normal clotting factors in their blood, leading to excessive bleeding and potentially death following minor injuries.

Therefore, the correct answer is A, "A recessive gene responsible for the condition is present on the X-chromosome".

Haemophilia is a genetic disorder characterized by the inability of blood to clot, leading to prolonged bleeding.

This is due to a reduction or complete absence of clotting factors in the blood.

It does not involve disseminated intravascular coagulation, thromboembolism, or an increase in the viscosity of the blood.

Thus, the correct answer is C, "Blood fails to clot after an injury".

The phenotype of an organism is influenced by a combination of its genotype and the environment in which it exists.

Genes, which are passed down from ancestors (the genotype), have a significant impact on an organism's phenotype. Nevertheless, the environment also plays a critical role in determining phenotype.

As a result, the correct answer is C, "Interactions between the genotype and environment".

Gregor Mendel, the father of genetics, carried out his groundbreaking experiments on Pea plants. However, he did not consider every possible trait in his studies.

Of the options provided, Mendel did not include pod length in his experimental observations.

Haemophilia A and B are genetic disorders inherited in an X-linked recessive pattern, implying that the faulty gene causing the disease is located on the X chromosome.

Men, who only have one X chromosome, can contract the disease if they inherit an affected gene. Women, who have two X chromosomes, must inherit two affected genes to get the disease, which is quite rare.

Thus, the correct answer is B, "Disorder linked to a recessive gene on the X chromosome".

Linked genes are those located on the same chromosome. They tend to be physically associated and usually inherited together, barring any occurrence of crossing over.

The formation of a linkage group is tied to genes on the same chromosome, making option B, "They constitute a single linkage group", the correct answer.

Inheritance that strictly follows a male line – from grandfather to father to son, signifies that the gene for the trait is located on the Y-chromosome.

This pattern of inheritance is consistent with Y-linked genes, thus the correct answer is C, "Y-chromosome".

Mendel's law of independent assortment is derived from a dihybrid cross and it suggests that each pair of alleles segregates independently of any other pair during gamete formation.

This law is most applicable to genes on nonhomologous chromosomes or those positioned far apart on the same chromosome. Hence, option D, "Law of independent assortment", is the correct answer.

In the context of heterozygous individuals or hybrids, of the two alleles that represent alternate traits, the one that expresses in the first filial (F1) generation is known as the dominant trait.

The principle of dominance suggests that the other allele, known as the recessive trait, doesn't express in heterozygous individuals. Therefore, the correct answer is B, "Dominant traits".

While a diploid organism typically has two alleles for an autosome gene, a gene can have more than two allelic forms. This is known as multiple allele inheritance, for example, the ABO blood group type.

As such, the correct answer is C, "Blood groups".

The ABO blood group was the first multiple allelic blood group system discovered in humans. It presents four different phenotypes, each distinguished based on specific antigens on the surface of Red Blood Cells (RBCs).

Therefore, the correct answer is C, "ABO blood group".

Hemophilia is categorized as a sex-linked disease, caused by a recessive sex-linked gene carried by the X-chromosome.

Given these characteristics, the most accurate answer is D, "X-linked recessive gene disorder."

Mendel selected seven traits for his pea plant experiment. Among these, the nature of trichomes, whether glandular or non-glandular, was not considered.

Therefore, the correct answer is A, "Trichomes – Glandular or non – glandular."

Mendelian recombinations occur when genes located on different chromosomes assort independently.

Given this, the correct answer is D, "Independent assortment of characters."

Genes are the fundamental units of inheritance and contain the information needed to express a specific trait in an organism.

The alternative form of a single gene that codes for contrasting traits is known as alleles. For example, tall and dwarf are alleles that determine the height of a pea plant. Therefore, the correct answer is B, "Alleles."

The XO type of sex determination system is one in which males possess only one X-chromosome along with the autosomes, while females have a pair of X-chromosomes.

This type of sex determination is seen in Grasshoppers. So, the correct answer is B, "Grasshopper."

Hemophilia is a sex-linked recessive disease. It affects a single protein that is part of the cascade of proteins involved in blood clotting.

A heterozygous female for hemophilia may transmit the disease to her sons. Hence, the correct answer is D, "A single protein involved in the clotting of blood is affected."

The probability of a couple having a son or a daughter is 1/2 (50%). This is because the sex of the offspring is determined by the presence or absence of the Y chromosome from the father.

Considering this, the probability of a couple having four sons in a row is (1/2)^4 = 1/16. Therefore, the right answer is C, "1/16."