Life on Earth
Chapter 13
Patterns of Inheritance
Self-Quiz
An organism is described as Rr : red. The Rr is the organism's [A]; red is the organism's [B]; and the organism is [C].
[A] phenotype; [B] genotype; [C] degenerate
[A] karyotype; [B] hybrid; [C] recessive
[A] genotype; [B] phenotype; [C] heterozygous
[A] gamete; [B] linkage; [C] pleiotropic
[A] zygote; [B] epistasis; [C] homozygous
The 9:3:3:1 ratio is a ratio of
phenotypes in a test cross
phenotypes in a monohybrid cross
phenotypes in a dihybrid cross
genotypes in a monohybrid cross
genotypes in a dihybrid cross
A test cross is used to
demonstrate whether two genes are linked
test whether an organism expressing the dominant phenotype is homozygous or heterozygous
show whether inheritance is polygenic or Mendelian
determine whether a trait is sex-linked or autosomal
find out whether the trait is characterized by incomplete dominance
Which of the following statements rewords Mendel's first law in terms of what you know about genetics and meiosis?
Genes are arranged on sex chromosomes or autosomes.
If two genes are on two different chromosomes, then how alleles of one gene distribute into gametes does not influence how alleles of the other gene distribute.
If two genes are on the same chromosome, they are linked.
Two alleles of a gene do not mix with each other while they are in a heterozygous organism; they can appear unaltered in subsequent generations.
There would be no crossing over between X and Y chromosomes.
A man's lawyer tells him that he cannot use blood type as evidence in a paternity suit against him because the child could, in fact, be his according to blood type. Which of the following is the only possible combination supporting this hypothetical circumstance? (Answers are in the order: mother:father:child)
A:B:O
A:O:B
AB:A:O
AB:O:AB
B:O:A
A heterozygous red-eyed female Drosophila mated with a white-eyed male would produce
red-eyed females and white-eyed males in the F1
white-eyed females and red-eyed males in the F1
half red- and half white-eyed females and all white-eyed males in the F1
all white-eyed females and half red- and half white-eyed males in the F1
half red- and half white-eyed females as well as males in the F1
By crossing Aa x Aa, what is the ratio of phenotypes in the offspring produced? Assume complete dominance for the trait.
100% dominance
100% recessive
75% dominant: 25% recessive
50% dominant: 50% recessive
25% dominant: 75% recessive
The law of segregation states that
Each individual carries a single copy of each "factor."
Pairs of factors fuse during the formation of gametes.
Pairs of factors separate during the formation of gametes.
The sex chromosomes of males and females differ.
There is an independent assortment of non-homologous chromosomes during meiosis.
A recessive gene is defined as one
that is not expressed as strongly as a dominant allele
whose effect is masked by a dominant allele
that appears only in a heterozygote
that produces no effect when present in the homozygous condition
that must be lethal in the homozygous condition
All of the following statements are true, except:
Individuals with the same phenotype might have different genotypes.
Matings between individuals with dominant phenotypes cannot produce offspring with recessive phenotypes.
Matings between individuals with recessive phenotypes usually do not produce offspring with dominant phenotypes.
Individuals with the same genotype might have different phenotypes.
All of the above choices are correct.
The physical appearance of an organism's genes is its
environment
genotype
phenotype
genetic code
number of chromosomes
A cross between two heterozygous (AaBb) parents produces offspring with an expected phenotypic ratio of (assume complete dominance)
3 : 1
1 : 1
9 : 3 : 3 : 1
1 : 1 : 2 : 1 : 1 : 2
1 : 1 : 1 : 1
Mendel explained his dihybrid cross results by assuming that the two traits
are inherited independently of each other
are linked together
influence each other during gamete formation
are always heterozygous
were part of the sex chromosomes
In fruit flies, sperm cells receive autosomes and
an X and a Y chromosome
either an X or a Y chromosome
no sex chromosomes
a Y chromosome
an X chromosome
An adopted child has blood type O. She discovers that her biological father has blood type A. This means that her biological mother cannot have the following blood type
A
B
AB
O
The mother could have any of the above blood types.
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