Ch 12 assignment
Which of the following plants was the main organism for Mendel's genetic experiments?
Pea plants
Which of the following conditions is inherited due to a dominant allele?
Juvenile glaucoma
Which of these traits exhibit a dominant mode of inheritance?
Mid-digital hair Polydactyly Hypercholesterolemia
Juvenile glaucoma is a hereditary disease that causes blindness due to the degeneration of nerves in which of the following?
Optic nerve
A 9:3:3:1 ratio is obtained in the F2 generation of a dihybrid cross when alleles assort from one another.
independently
albinism
lack of melanin pgimentation
A cross in which only a single trait is considered is called a(n) cross or single factor cross.
monohybrid
An experimental cross where only a single characteristic is considered (for example, flower color) is called
monohybrid
In order to determine the likelihood of having a flipped coin come up on heads three times in a row, you would use the
multiplication rule
An example of a cross is using pollen from a green-seeded pea plant to fertilize a yellow-seeded pea plant and then using pollen from a yellow-seeded pea plant to fertilize a green-seeded pea plant.
reciprocal
Traits that exhibit continuous variation are also called
quantitative traits
Place the three stages of Mendel's experiments in the correct order from first (on top) to last.
1. Allowing plants to self-cross to ensure they are true-breeding 2. Reciprocal crosses between true-breeding varieties 3. allowing hybrid offspring to self-fertilize
When performing a monohybrid cross, Mendel noticed that not all individuals in the F2 generation were true breeding. What proportion were not?
1/2 of the F2 individuals exhibiting the dominant form were not true breeding.
In a certain plant, fruit color is affected by an epistatic interaction between two genes. The fruit is red in the presence of at least one dominant allele of either or both gene A or gene B, and white when there are no dominant alleles present. What proportion of the offspring of a cross of AaBb x AaBb plants is expected to be red?
15/16
One of the parents in a dihybrid cross has the genotype AABb. How many types of gametes can this parent produce?
2
What was the ratio that Mendel observed between dominant and recessive traits in the F2 offspring of a monohybrid cross?
3 dominant:1 recessive
In pea plants, the allele T encodes for tall plants, while the allele t encodes for dwarf plants. If a true-breeding tall pea plant is crossed with a true-breeding dwarf pea plant what are the expected genotypes of the offspring?
All Tt
Which of the following is NOT one of the three main stages that Mendel conducted his experiments in?
Back crosses between F1 and P individuals
In a typical monohybrid cross, all of the offspring in which generation will exhibit a single trait without blending?
F1
What type of experiment involves mating two individuals with different characteristics to each other? One individual provides females gametes, while the other provides male gametes.
Hybridization
Which of the following are examples of environmental effects on phenotype?
The number of seeds eaten by a bird affects its weight. The amount of sunlight experienced by a sunflower affects the number of seeds produced.
Choose statements that correctly refer to components of Mendel's five-element model (please note that the answers use the modern term gene instead of factor).
The presence of an allele doesn't ensure that it will be expressed. Alternative forms of genes are called alleles. Parents transmit genes to offspring. The two alleles remain discrete.
Which of these are not reasons that Mendel chose to study the garden pea: Short generation time Lots of varieties They were inexpensive to buy Earlier investigators had used the garden pea They can self-fertilize Long generation time
They were inexpensive to buy Long generatio time
Mendel's data and observations did support the independent assortment hypothesis.
True
True or false: Mendel found that plants exhibiting the recessive trait were usually not true-breeding.
True: Mendel found that plants exhibiting the recessive trait were always true-breeding.
color blindness is
a recessive trait
Mendel's observations supported the independent___hypothesis
assortment
When continuous traits are graphed in the form of a histogram with the phenotype on the X-axis, and the frequency of individuals with that phenotype on the Y-axis, a ____-shaped curve results.
bell
Prior to the work of Mendel, inheritance was viewed as resulting from
blending of traits from an offspring's parents
sickle cell anemia
defective hemoglobin
huntington disease
degeneration of nervous system
An____cross follows the simultaneous inheritance of two different characters.
dihybrid
When the interaction of genes alters genetic ratios, this is called .
epistasis
polydactyly
extra fingers and toes
An individual's total set of alleles for a particular trait is called his/her
genotype
Type A -
have galactosamine
Type B -
have galactose
If the offspring from a testcross contain only heterozygotes, the genotype of the unknown parent must be
homozygous dominant
Pedigree analysis is typically used for studying:
human traits that follow simple inheritance patterns
hemophilia
inability of blood to clot properly
The appropriate time to use the product rule is when dealing with events that are:
independent
In the monohybrid crosses performed by Mendel, the F1 plants always displayed ____.
one trait
This analysis is appropriate for studying traits, such as genetic diseases, that follow simple Mendelian patterns:
pedigree
The physical appearance or other observable characteristic of an individual is called his/her .
phenotype
Sickle cell anemia is caused by a___allele because this mutation has more than one effect on the phenotype.
pleiotropic
cross-fertilization
pollen collected from a white flower introduced into a purple flower with male parts removed
reciprocal fertilization
pollen from a white-flowered plant is used to fertilize a purple-flowered plant, while pollen from a purple-flowered plant is used to fertilize a white-flowered plant
Quantitative traits are usually
polygenic
Human height is an example of a trait that has a continuous distribution of phenotypes. Human height is therefore an example of
polygenic inheritance
Continuous phenotypic variation results from
polygenic inheritance and independent segregation of genes
To calculate the probability that if a woman has four children, they will all be girls, you should use the
product rule
An_______can be used to predict the outcome of a simple genetic cross.
punnett square
self-fertilization
takes place within an individual flower if it is not disturbed
In order for Mendel's simple ratios to hold true, the following assumption must be made:
that the traits are inherited independently
In Mendel's experiments, he observed a 3:1 ratio between dominant and recessive traits in
the F2 generation of monohybrid crosses.
Which of the following is NOT a component of Mendel's five-element model (please note that the answers use the modern term gene instead of factor)?
the two alleles are usually the same
Reasons why Mendel chose to study with pea plants
they had short generation time, lots of varieties, earlier investigators had used the garden pea, and they can self-fertilize
Prior to the 20th century, the two main ideas that provided the basis for most thinking about heredity were
traits are transmitted directly from parents to offspring and heredity occurs within species
A hybridization experiment involves mating
two individuals with different characteristics to each other
The probability of genotypes in an independently assorted dihybrid cross is based on the probabilities of
two monohybrid crosses
multiplication rule
used for independent events
addition rule
used for mutually exclusive events
A Punnett square has rows and columns which represent gametes made by males and females. At the intersection of each row and column we combine the corresponding gametes to produce the genotype of a potential .
zygote or offspring
