Mendel And Genetics

Question 0

Define gene and allele, and discuss their relationship

Answer 0

A gene is a stretch of DNA that controls some features of an organism( hair color) a discrete unit of inheritance. Each diploid organism has two alleles for each gene, one inherited from the mother and another from the father

Question 1

Define trait and character, and discuss their relationship

Answer 1

A character is a feature of an organism( color ) A trait is a form of a character ( red or white)

Question 2

Why were peas a good organism to use to research genetic?

Answer 2

They reproduce quickly have a larger number of offsprings, they have many varieties with many traits, and is easy to control their reproduction

Question 3

Discuss one way in which a trait can skip generations?

Answer 3

If a trait is homologous recessive it can be present in a heterozygous carrier and not be express until it is restore into its homologous condition. Also may X-link traits are represent in male, but only carried by their daughters

Question 4

Describe the laws of segregation and independent assortment in the context of how they act in Mendelian genetics

Answer 4

Segregation act to separate the traits an organism receive from its mother and father. Independent assortment acts to separate these traits from another

Question 5

Describe dominant and recessive alleles

Answer 5

Recessive allele are only express in organism if the are homologous. Often because they have a defective form of a gene( white is not a color but red is a pigment) dominant alleles are so called because they can mask recessive alleles. In heterozygous they are dominant

Question 6

What is the difference between heterozygous and homozygous

Answer 6

Homozygous is having two alleles for the same trait(aa AA) heterozygous is having two alleles for different traits. Aa

Question 7

What are the differences between phenotype and genotype.

Answer 7

Genotype is the actual genetic makeup of an organism alleles, and can be homozygous dominant, heterozygous, or homologous recessive. Phenotype is the outward expression of the genotype, the physical appearance. It is either dominant or recessive

Question 8

What is test cross?

Answer 8

An individual of unknown genotype can have its genotype be matting with an individual of an unknown genotype( homologous recessive genes) the phenotypes of the offsprings will indicate the genotype of the parent in question

Question 9

When are multiplication and addition rules used for determining the probability of the occurrence of a particular genotype/phenotype

Answer 9

The multiplication rule is used when multiple outcomes need to occurred together. The addition rule is used when one or the other of multiple outcomes occurred.

Question 10

What are the difference between incomplete dominance and codominance ?

Answer 10

Incomplete dominance results in blending, codominance results in a mosaic pattern

Question 11

Can one gene have multiple alleles?

Answer 11

Doesn’t have to just have two alleles. The blood type has three alleles. Some genes have dozen of alleles

Question 12

Describe AOB blob group in humans

Answer 12

The gene codes for specific antigens on the outside of the red blood cells. Type A and B code for different antigen, and are codominant . Type o codes for no antigens and it’s recessive

Question 13

Define pleiotropy

Answer 13

When one gene affect multiple traits

Question 14

Define apistasis

Answer 14

When one gene affect and other gene’s expression

Question 15

What is pedigree ?

Answer 15

A family tree with information on the phenotypes of individuals

Question 16

What is a carrier ?

Answer 16

An individual who is heterozygous for a trait. The phenotype is dominant, but genotype has recessive allele

Question 17

In the pedigree analysis, what are three characteristics of an autosomal dominant trait?

Answer 17

The trait usually occurs in every generation, at least one parent of an affected child is affected, when both are affected, they may have unaffected children( parents are heterozygous)

Question 18

In the pedigree analysis what are the 3 characteristics of an autosomal recessive trait?

Answer 18

Traits often skip generations
When both parents are affected, all children are affected
When both parents are unaffected they may have affected children ( if parents are heterozygous)

Question 19

In the pedigree analysis what are the 3 characteristics of an X linked trait?

Answer 19

Condition occurs predominantly in males
Affected males do not have affected offsprings( unless mother is affected carrier)
Affected females will have affected sons and carrier daughters