WorksheetsD3.2 AHL Inheritance
Total questions: 29
Worksheet time: 15mins
What is the expected phenotype ratio in the offspring of a dihybrid cross between an individual heterozygous for both traits and an individual homozygous recessive for both traits?
(a)
According to Mendel's second law, the Law of Independent Assortment, what happens to two or more pairs of alleles during meiosis?
a) They are always inherited together
b) They segregate independently, if the genes are not linked
c) They always segregate together
d) Their segregation depends on the type of organism
In Morgan's experiments with Drosophila, what did he observe about the inheritance of eye color and wing shape?
a) They always followed Mendelian ratios
b) They never followed Mendelian ratios
c) They sometimes followed Mendelian ratios and sometimes did not
d) They were not related to each other
What does it mean if two genes are "unlinked"?
a) They are located on the same chromosome
b) They are located on different chromosomes
c) They code for the same protein
d) They are never inherited together
What did Morgan's experiments with Drosophila confirm about linked genes?
a) They do not exist in Drosophila
b) They always result in Mendelian ratios
c) They can result in non-Mendelian ratios
d) They are only found on the sex chromosomes
In the sweet pea experiment, what did the appearance of a small number of offspring with red flowers and long pollen or purple flowers and round pollen suggest?
a) The genes for flower color and pollen shape are unlinked
b) The genes for flower color and pollen shape are incompletely dominant
c) Recombination occurred between the linked genes
d) The results were due to experimental error
What are recombinants?
a) Chromosomes with rearranged genetic information
b) Proteins resulting from linked genes
c) Offspring that are identical to the parents
d) Mutations that occur during meiosis
How are recombinants produced in crosses involving linked genes?
a) Through independent assortment
b) Through crossing over during meiosis
c) Through mutations
d) They are not produced in linked gene crosses
In a dihybrid cross between flies heterozygous for vestigial wing and ebony body, what fraction of the F2 offspring are expected to have normal wings and ebony bodies?
a) 1/16
b) 3/16
c) 9/16
d) 12/16
In the sweet pea experiment by Bateson and Punnett, what did the results of the dihybrid cross indicate about the genes for flower color and pollen shape?
a) They are located on different chromosomes
b) They are linked on the same chromosome
c) They are incompletely dominant
d) They are codominant
What is the term for the physical exchange of genetic material between homologous chromosomes during meiosis?
a) Independent assortment
b) Crossing over
c) Linkage
d) Recombination
Where can the locus of specific genes in the human genome be found?
a) In textbooks
b) In online databases
c) By looking through a microscope
d) It's impossible to know
Where are the genes for round/wrinkled seeds and yellow/green cotyledons located in the pea plant?
a) On the same chromosome, close together
b) On the same chromosome, far apart
c) On different chromosomes
d) In the cytoplasm, not the nucleus
How did Morgan's work contribute to the development of the Chromosome Theory of Inheritance?
a) It provided evidence that genes are located on chromosomes
b) It disproved the idea that genes are located on chromosomes
c) It showed that inheritance patterns are not related to chromosomes
d) It had no impact on the Chromosome Theory of Inheritance
What does it mean if two genes are "linked"?
a) They are located close together on the same chromosome
b) They are located on different chromosomes
c) They code for the same protein
d) They are always inherited together, regardless of location
In a dihybrid cross, what is the expected ratio of genotypes in the offspring if the genes are linked with a recombination frequency of 20%?
a) 9:3:3:1
b) 1:1:1:1
c) 40:10:10:40
d) 20:20:20:20
What is the primary reason that linked genes do not follow Mendelian ratios?
a) They are located on different chromosomes
b) They are always homozygous
c) They are inherited together more often than expected by chance
d) They mutate more frequently than unlinked genes
How did Thomas Morgan's work with Drosophila contribute to the field of genetics?
a) It proved that Mendel's laws were incorrect
b) It showed that linked genes can result in non-Mendelian ratios
c) It demonstrated that genes are not located on chromosomes
d) It had no significant impact on genetics
Why is Drosophila a useful model organism for genetic studies?
a) It has a long generation time
b) It has a large number of chromosomes
c) It produces very few offspring
d) It is easy to handle and culture
What is the expected genotype ratio in the offspring of a dihybrid cross between individuals heterozygous for both traits?
a) 1:1:1:1
b) 9:3:3:1
c) 1:2:1:2:4:2:1:2:1
d) 3:6:3:1
What is the main difference between gene linkage and sex linkage?
a) Gene linkage refers to genes on the same chromosome; sex linkage refers to genes on sex chromosomes
b) Gene linkage refers to genes on sex chromosomes; sex linkage refers to genes on the same chromosome
c) Gene linkage only occurs in plants; sex linkage only occurs in animals
d) There is no difference; the terms are interchangeable
Which of the following is NOT an advantage of using Drosophila for genetic studies?
a) Short generation time
b) Easily distinguishable sexes
c) Large number of offspring
d) Large number of chromosomes
What is the phenotype ratio of offspring in a dihybrid cross when one parent is heterozygous for both genes and the other is homozygous recessive?
a) 1:1:1:1
b) 3:1:3:1
c) 9:3:3:1
d) 12:3:1:0
What is the term for an individual with two different alleles for a particular gene?
a) Homozygous
b) Heterozygous
c) Purebred
d) Hybrid
Which of the following is true about scientific laws versus theories?
a) Laws and theories are essentially the same thing
b) Laws provide explanations, theories generate predictions
c) Laws predict results, theories provide explanations
d) Laws are proven, theories are not
In Figure D3.2.20, what fraction of the F2 offspring are expected to have the genotype RrYy?
a) 1/4
b) 1/16
c) 4/16
d) 9/16
What is the term for the position of a gene on a chromosome?
a) Allele
b) Genotype
c) Locus
d) Phenotype
In Figure D3.2.19, what do the round yellow peas in the F1 generation indicate about the alleles for round/wrinkled seeds and yellow/green cotyledons?
a) The alleles for round and yellow are dominant
b) The alleles for round and yellow are recessive
c) The alleles for wrinkled and green are dominant
d) The alleles have incomplete dominance
In Mendel's dihybrid cross, what is the ratio of the F2 generation phenotypes of round yellow peas, round green peas, wrinkled yellow peas, and wrinkled green peas?
a) 1:1:1:1
b) 3:1:3:1
c) 9:3:3:1
d) 12:3:1:0
