Polygenic inheritance occurs when one characteristic is controlled by two or more genes. Often the genes are large in quantity but small in effect. Examples of human polygenic inheritance are height, skin color, eye color and weight. Polygenes exist in other organisms, as well.
What are examples of polygenic diseases?
Polygenic disease: A genetic disorder that is caused by the combined action of more than one gene. Examples of polygenic conditions include hypertension, coronary heart disease, and diabetes.
Is thalassemia a polygenic inheritance?
In general, thalassemia is inherited in an autosomal recessive manner; however, the inheritance can be quite complex as multiple genes can influence the production of hemoglobin. Most people affected by beta thalassemia have mutations in both copies of the HBB gene in each cell .
Which of the following is an example of polygenic inheritance in plants?
Polygenic inheritance in plants includes the colour and shape of the stem, pollen, flower, yield, oil content, size of a seed, time to mature or flower, etc.Which is not an example of a polygenic trait?
Blood type AB in humans, for instance, is not a polygenic trait. Rather, it is a case of codominance. The two alleles for A and B antigens on the red blood cells of blood type AB individuals are dominant, and therefore are expressed together.
Which is an example of co dominance?
Codominance means that neither allele can mask the expression of the other allele. An example in humans would be the ABO blood group, where alleles A and alleles B are both expressed. So if an individual inherits allele A from their mother and allele B from their father, they have blood type AB.
Which of the following phenotypes is an example of polygenic inheritance quizlet?
An example of polygenic inheritance in humans is skin color. The skin color is controlled by 1, 3, & 4 genes. You can tell that it is polygenic in a population by the people having different types of skin color. Many different phenotype.
Is cretinism a hereditary disease?
Cretinism is a non-hereditary disease that is caused in infants due to decrease triiodothyronine (T3) and tetraiodothyronine (T4) hormone synthesis and secretion. The infant is mentally retarded and is called a cretin. The main reason as to why cretinism is seen in children is iodine deficiency.Is ABO blood group polygenic?
GenotypePhenotype (blood type)IBiBiiOIAIBAB
What type of inheritance is thalassemia?Thalassemia major and thalassemia intermedia are inherited in an autosomal recessive pattern , which means both copies of the HBB gene in each cell have mutations.
Article first time published onIs beta thalassemia inherited?
Beta thalassemia is a genetic disease inherited from one or both parents. The only risk factor is having a family history of the disease.
Is polygenic inheritance an example of Codominance?
In codominance, different alleles of a single gene affect the resulting trait. Examples of polygenic traits in humans are height, weight, skin color, and eye color.
Which of the following is an example of a Meristic trait?
Meristic traits are those in which the phenotypes are recorded by counting whole numbers. Examples of meristic traits include the num- ber of seeds in a pod or the number of eggs laid by a chicken in a year. These are quantitative traits, but they do not have an infinite range of phenotypes.
Why Is height a good example of polygenic inheritance?
Why is height a good example of polygenic inheritance? because the characters vary in the population in gradients along a continuum.
Which is an example of a polygenic trait quizlet?
A polygenic trait is a characteristic, sometimes we call them phenotypes, that are affected by many, many different genes. A classic example of this would be height. Height in humans is very strongly genetically controlled, but there are many, many different genes that control height.
Which of the following phenotypes is an example?
Examples of phenotypes include height, wing length, and hair color. Phenotypes also include observable characteristics that can be measured in the laboratory, such as levels of hormones or blood cells.
Which scenario is an example of epistasis?
An example of epistasis is pigmentation in mice. The wild-type coat color, agouti (AA), is dominant to solid-colored fur (aa). However, a separate gene (C) is necessary for pigment production.
What are some examples of incomplete dominance?
- Chickens with blue feathers are an example of incomplete dominance. …
- When a long-furred Angora rabbit and a short-furred Rex rabbit reproduce, the result can be a rabbit with fur longer than a Rex, but shorter than an Angora. …
- Tail length in dogs is often determined by incomplete dominance.
Which is an example of codominance of inheritance quizlet?
Codominance is the type of inheritance that occurs when a heterozygote displays both alleles equally. An example would be AB blood type in humans or a red and white striped flower.
How is sickle cell an example of codominance?
The altered form of hemoglobin that causes sickle-cell anemia is inherited as a codominant trait. Specifically, heterozygous (Ss) individuals express both normal and sickle hemoglobin, so they have a mixture of normal and sickle red blood cells.
What is an example of pleiotropy?
One of the most widely cited examples of pleiotropy in humans is phenylketonuria (PKU). This disorder is caused by a deficiency of the enzyme phenylalanine hydroxylase, which is necessary to convert the essential amino acid phenylalanine to tyrosine.
Is Abo an example of pleiotropy?
The ABO blood type is one example. In some cases, genes and their alleles may be expressed in complex ways. That is, no single trait can be attributed to a given allele. Pleiotropy describes this situation, and includes the examples of pigmentation and crossed eyes in the case of albinism.
What is the example of ABO blood type?
The ABO Blood Group Is an Example of Multiple Alleles The ABO blood group is a classic example of this. Every person has two number 9 chromosomes and, therefore, two alleles for ABO blood types. However, there are three possible alleles—IA, IB, and i (Type O)—that can occur on each number 9 chromosome.
What is the difference between cretinism and dwarfism?
In several hormonal disorders and hereditary conditions dwarfism is associated with subnormal intelligence. Inadequate production of thyroid hormone during gestation and early infancy results in a condition known as cretinism, which is characterized by growth retardation and severe mental retardation.
Which disease is hereditary?
Examples of single gene inheritance disorders include: Cystic fibrosis. Sickle-cell anemia. Marfan syndrome.
What hormone causes cretinism?
Cretinism is a condition of severe physical and mental retardation due to iodine deficiency, and specifically due to deficiency of thyroid hormones during early pregnancy.
Is thalassemia genetic or environmental?
Thalassemia is a general term for a group of congenital, genetic disorders characterized by low levels of hemoglobin, decreased red blood cell production, and anemia. There are two main forms – alpha thalassemia and beta thalassemia – each with various subtypes.
What kind of inheritance is sickle cell anemia?
This condition is inherited in an autosomal recessive pattern , which means both copies of the gene in each cell have mutations. The parents of an individual with an autosomal recessive condition each carry one copy of the mutated gene, but they typically do not show signs and symptoms of the condition.
Is thalassemia a mutation?
Thalassemia is caused by mutations in the DNA of cells that make hemoglobin — the substance in red blood cells that carries oxygen throughout your body. The mutations associated with thalassemia are passed from parents to children.
Is Sickle Cell A thalassemia?
Sickle beta thalassemia is an inherited condition that affects hemoglobin, the protein in red blood cells that carries oxygen to different parts of the body. It is a type of sickle cell disease.
What chromosome is beta thalassemia?
The beta globin (HBB) gene maps in the short arm of chromosome 11 in a region also containing the delta globin gene, the embryonic epsilon gene, the fetal A-gamma and G-gamma genes, and a pseudogene (ψB1).
