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Gregor Mendel used pea plants to study

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Title: Gregor Mendel used pea plants to study


1
Gregor Mendel used pea plants to study
  • flowering.
  • gamete formation.
  • the inheritance of traits.
  • cross-pollination.

2
Offspring that result from crosses between
parents with different traits
  • are true-breeding.
  • make up the F2 generation.
  • make up the parental generation.
  • are called hybrids.

3
Gregor Mendel removed the male parts from the
flowers of some plants in order to
  • prevent hybrids from forming.
  • prevent cross-pollination.
  • stimulate self-pollination.
  • make controlled crosses between plants.

4
The chemical factors that determine traits are
called
  • alleles.
  • traits.
  • genes.
  • characters.

5
Gregor Mendel concluded that traits are
  • not inherited by offspring.
  • inherited through the passing of factors from
    parents to offspring.
  • determined by dominant factors only.
  • determined by recessive factors only.

6
When Gregor Mendel crossed a tall plant with a
short plant, the F1 plants inherited
  • an allele for tallness from each parent.
  • an allele for tallness from the tall parent and
    an allele for shortness from the short parent.
  • an allele for shortness from each parent.
  • an allele from only the tall parent.

7
The principle of dominance states that
  • all alleles are dominant.
  • all alleles are recessive.
  • some alleles are dominant and others are
    recessive.
  • alleles are neither dominant nor recessive.

8
When Gregor Mendel crossed true-breeding tall
plants with true-breeding short plants, all the
offspring were tall because
  • the allele for tall plants is recessive.
  • the allele for short plants is dominant.
  • the allele for tall plants is dominant.
  • they were true-breeding like their parents.

9
If a pea plant has a recessive allele for green
peas, it will produce
  • green peas if it also has a dominant allele for
    yellow peas.
  • both green peas and yellow peas if it also has a
    dominant allele for yellow peas.
  • green peas if it does not also have a dominant
    allele for yellow peas.
  • yellow peas if it does not also have a dominant
    allele for green peas.

10
A tall plant is crossed with a short plant. If
the tall F1 pea plants are allowed to
self-pollinate,
  • the offspring will be of medium height.
  • all of the offspring will be tall.
  • all of the offspring will be short.
  • some of the offspring will be tall, and some will
    be short.

11
In the P generation, a tall plant was crossed
with a short plant. Short plants reappeared in
the F2 generation because
  • some of the F2 plants produced gametes that
    carried the allele for shortness.
  • the allele for shortness is dominant.
  • the allele for shortness and the allele for
    tallness segregated when the F1 plants produced
    gametes.
  • they inherited an allele for shortness from one
    parent and an allele for tallness from the other
    parent.

12
In the P generation, a tall plant was crossed
with a short plant. If alleles did not segregate
during gamete formation,
  • all of the F1 plants would be short.
  • some of the F1 plants would be tall and some
    would be short.
  • all of the F2 would be short.
  • all of the F2 plants would be tall.

13
When you flip a coin, what is the probability
that it will come up tails?
  • 1/2
  • 1/4
  • 1/8
  • 1

14
The principles of probability can be used to
  • predict the traits of the offspring produced by
    genetic crosses.
  • determine the actual outcomes of genetic crosses.
  • predict the traits of the parents used in genetic
    crosses.
  • decide which organisms are best to use in genetic
    crosses.

15
In the P generation, a tall plant is crossed with
a short plant. The probability that an F2 plant
will be tall is
  • 25.
  • 50.
  • 75
  • 100.

16
Organisms that have two identical alleles for a
particular trait are said to be
  • hybrid.
  • homozygous.
  • heterozygous.
  • dominant.

17
Figure 111
18
In the Punnett square shown in Figure 111, which
of the following is true about the offspring
resulting from the cross?
  • About half are expected to be short.
  • All are expected to be short.
  • About half are expected to be tall.
  • All are expected to be tall.

19
A Punnett square shows all of the following EXCEPT
  • all possible results of a genetic cross.
  • the genotypes of the offspring.
  • the alleles in the gametes of each parent.
  • the actual results of a genetic cross.

20
If you made a Punnett square showing Gregor
Mendels cross between true-breeding tall plants
and true-breeding short plants, the square would
show that the offspring had
  • the genotype of one of the parents.
  • a phenotype that was different from that of both
    parents.
  • a genotype that was different from that of both
    parents.
  • the genotype of both parents.

21
What principle states that during gamete
formation genes for different traits separate
without influencing each others inheritance?
  • principle of dominance
  • principle of independent assortment
  • principle of probabilities
  • principle of segregation

22
Figure 112
23
The Punnett square in Figure 112 shows that the
gene for pea shape and the gene for pea color
  • assort independently.
  • are linked.
  • have the same alleles.
  • are always homozygous.

24
How many different allele combinations would be
found in the gametes produced by a pea plant
whose genotype was RrYY?
  • 2
  • 4
  • 8
  • 16

25
If a pea plant that is heterozygous for round,
yellow peas (RrYy) is crossed with a pea plant
that is homozygous for round peas but
heterozygous for yellow peas (RRYy), how many
different phenotypes are their offspring expected
to show?
  • 2
  • 4
  • 8
  • 16

26
Situations in which one allele for a gene is not
completely dominant over another allele for that
gene are called
  • multiple alleles.
  • incomplete dominance.
  • polygenic inheritance.
  • multiple genes.

27
A cross of a black chicken (BB) with a white
chicken (WW) produces all speckled offspring
(BBWW). This type of inheritance is known as
  • incomplete dominance.
  • polygenic inheritance.
  • codominance.
  • multiple alleles.

28
Variation in human skin color is an example of
  • incomplete dominance.
  • codominance.
  • polygenic traits.
  • multiple alleles.

29
Gregor Mendels principles of genetics apply to
  • plants only.
  • animals only.
  • pea plants only.
  • all organisms.

30
Why did Thomas Hunt Morgan use fruit flies in his
studies?
  • Fruit flies produce a large number of offspring.
  • Fruit flies take a long time to produce
    offspring.
  • Fruit flies share certain characteristics with
    pea plants.
  • Fruit flies have a long lifespan.

31
A male and female bison that are both
heterozygous for normal skin pigmentation (Aa)
produce an albino offspring (aa). Which of
Mendels principles explain(s) why the offspring
is albino?
  • dominance only
  • independent assortment only
  • dominance and segregation
  • segregation only

32
The number of chromosomes in a gamete is
represented by the symbol
  • Z.
  • X.
  • N.
  • Y.

33
If an organisms diploid number is 12, its
haploid number is
  • 12.
  • 6.
  • 24.
  • 3.

34
Gametes have
  • homologous chromosomes.
  • twice the number of chromosomes found in body
    cells.
  • two sets of chromosomes.
  • one allele for each gene.

35
Gametes are produced by the process of
  • mitosis.
  • meiosis.
  • crossing-over.
  • replication.

36
What is shown in this figure?
  • independent assortment
  • anaphase I of meiosis
  • crossing-over
  • replication

37
Chromosomes form tetrads during
  • prophase I of meiosis.
  • metaphase I of meiosis.
  • interphase.
  • anaphase II of meiosis.

38
What happens between meiosis I and meiosis II
that reduces the number of chromosomes?
  • Crossing-over occurs.
  • Metaphase occurs.
  • Replication occurs twice.
  • Replication does not occur.

39
Unlike mitosis, meiosis results in the formation
of
  • diploid cells.
  • haploid cells.
  • 2N daughter cells.
  • body cells.

40
Unlike mitosis, meiosis results in the formation
of
  • two genetically identical cells.
  • four genetically different cells.
  • four genetically identical cells.
  • two genetically different cells.

41
Crossing-over rarely occurs in mitosis, unlike
meiosis. Which of the following is the likely
reason?
  • Chromatids are not involved in mitosis.
  • Tetrads rarely form during mitosis.
  • A cell undergoing mitosis does not have
    homologous chromosomes.
  • There is no prophase during mitosis.

42
Which of the following assort independently?
  • chromosomes
  • genes on the same chromosome
  • multiple alleles
  • codominant alleles

43
Linked genes
  • are never separated.
  • assort independently.
  • are on the same chromosome.
  • are always recessive.

44
If the gene for seed color and the gene for seed
shape in pea plants were linked,
  • all of Mendels F1 plants would have produced
    wrinkled, green peas.
  • Mendels F2 plants would have exhibited a
    different phenotype ratio for seed color and seed
    shape.
  • Mendels F1 plants would have exhibited a
    different phenotype ratio for seed color and seed
    shape.
  • all of Mendels P plants would have produced
    wrinkled, green peas.

45
Gene maps are based on
  • the frequencies of crossing-over between genes.
  • independent assortment.
  • genetic diversity.
  • the number of genes in a cell.

46
If two genes are on the same chromosome and
rarely assort independently,
  • crossing-over never occurs between the genes.
  • crossing-over always occurs between the genes.
  • the genes are probably located far apart from
    each other.
  • the genes are probably located close to each
    other.

47
The farther apart two genes are located on a
chromosome, the
  • less likely they are to be inherited together.
  • more likely they are to be linked.
  • less likely they are to assort independently.
  • less likely they are to be separated by a
    crossover during meiosis.

48
A trait is a specific characteristic that varies
from one individual to another.
_________________________
  • True
  • False

49
Gregor Mendel concluded that the tall plants in
the P generation passed the factor for tallness
to the F1 generation. _________________________
  • True
  • False

50
An organism with a dominant allele for a
particular form of a trait will sometimes exhibit
that trait. _________________________
  • True
  • False

51
True-breeding plants that produced axial flowers
were crossed with true-breeding plants that
produced terminal flowers. The resulting
offspring produced terminal flowers because the
allele for terminal flowers is recessive.
_________________________
  • True
  • False

52
When alleles segregate from each other, they
join. _________________________
  • True
  • False

53
If the alleles for a trait did not segregate
during gamete formation, offspring would always
show the trait of at least one of the parents.
_________________________
  • True
  • False

54
The principles of probability can explain the
numerical results of Mendels experiments.
_________________________
  • True
  • False

55
The probability that a gamete produced by a pea
plant heterozygous for stem height (Tt) will
contain the recessive allele is 100.
_________________________
  • True
  • False

56
If two speckled chickens are mated, according to
the principle of codominance, 25 of the
offspring are expected to be speckled.
_________________________
  • True
  • False

57
Coat color in rabbits is determined by a single
gene that has multiple alleles.
_________________________
  • True
  • False

58
If an organism has 16 chromosomes in each of its
egg cells, the organisms diploid number is 32.
_________________________
  • True
  • False

59
If an organism is heterozygous for a particular
gene, the two different alleles will be separated
during anaphase II of meiosis, assuming that no
crossing-over has occurred. ______________________
___
  • True
  • False

60
Mitosis results in two cells, whereas meiosis
results in one cell. _________________________
  • True
  • False

61
If an organism has four linkage groups, it has
eight chromosomes. _________________________
  • True
  • False

62
Genes in the same linkage group are usually
inherited separately. _________________________
  • True
  • False

63
The plants that Gregor Mendel crossed to produce
the F1 generation made up the ____________________
generation.
64
The different forms of a gene are called
____________________.
65
If the allele for shortness in pea plants were
dominant, all the pea plants in Mendels F1
generation would have been ____________________.
66
If the alleles for traits in pea plants did not
segregate during gamete formation, offspring that
were recessive for a trait could be produced only
by crossing two plants that were
____________________ for that trait.
67
____________________ is the likelihood that a
particular event will occur.
68
If you flip a coin five times and it comes up
heads each time, the probability that it will
come up heads the next time is ___________________
_.
69
Figure 111
70
In the Punnett square shown in Figure 111, the
genotypes of the offspring are ___________________
_.
71
Pea plants that are TT, ____________________, or
tt have different genotypes.
72
When two heterozygous tall pea plants are
crossed, the expected genotype ratio of the
offspring is _________________________.
73
The principle of independent assortment states
that ____________________ for different traits
can segregate independently during the formation
of gametes.
74
If pea plants that are homozygous for round,
yellow seeds (RRYY) were crossed with pea plants
that are heterozygous for round, yellow seeds
(RrYy), the expected phenotype(s) of the
offspring would be _________________________.
75
Crossing a pink-flowered four oclock with a
white-flowered four oclock will produce
pink-flowered offspring and ____________________-f
lowered offspring.
76
An organisms gametes have ____________________
the number of chromosomes found in the organisms
body cells.
77
Crossing-over occurs during the stage of meiosis
called ____________________.
78
The relative locations of each known gene can be
shown on a ____________________ map.
79
Define genetics.
80
What attributes of the garden pea plant made it
an excellent organism for Gregor Mendels genetic
studies?
81
What might have caused Gregor Mendel NOT to
conclude that biological inheritance is
determined by factors that are passed from one
generation to the next?
82
How many recessive alleles for a trait must an
organism inherit in order to exhibit that trait?
83
Figure 112
84
What is the phenotype ratio of the offspring in
the Punnett square shown in Figure 112?
85
A pea plant heterozygous for height and seed
color (TtYy) is crossed with a pea plant
heterozygous for height but homozygous recessive
for seed color (Ttyy). If 80 offspring are
produced, how many are expected to be tall and
have yellow seeds?
86
What might happen if the gametes of a species had
the same number of chromosomes as the species
body cells?
87
How many sets of chromosomes are in a diploid
cell?
88
Define homologous chromosomes.
89
What happens to the number of chromosomes per
cell during meiosis?
90
Contrast the cells produced by mitosis with those
produced by meiosis.
91
Why did Gregor Mendel not observe gene linkage
during his experiments with pea plants?
92
What is a linkage group?
93
What does a gene map show?
94
The gene map of a fruit flys chromosome 2 shows
the relative locations of the star eye, dumpy
wing, and black body genes to be 1.3, 13.0, and
48.5, respectively. Between which two genes does
crossing-over occur most frequently?
95
A pea plant with yellow seeds was crossed with a
plant with green seeds. The F1 generation
produced plants with yellow seeds. Explain why
green seeds reappeared in the F2 generation.
96
You wish to determine whether a tall pea plant is
homozygous or heterozygous for tallness. What
cross should you perform to arrive at your
answer? Explain your choice of cross
97
Why are the results of genetic crosses shown in
Punnett squares interpreted as probabilities, not
certainties? Give some specific reasons
98
A cross between two organisms heterozygous for
two different genes (AaBb) results in a
9  3  3  1 phenotype ratio among the
offspring. Is the offsprings genotype ratio the
same? Explain your answer
99
Explain the difference between incomplete
dominance and codominance.
100
A florist wants to guarantee that the seeds she
sells will produce only pink-flowered four
oclock plants. How should she obtain the seeds?
101
The stages of meiosis are classified into two
divisions meiosis I and meiosis II. Compare and
contrast these two divisions.
102
Suppose the homologous chromosomes that make up a
tetrad fail to separate during anaphase I of
meiosis. Predict the results of this event.
103
Explain why the daughter cells produced by
meiosis are genetically different from each
other, whereas the daughter cells produced by
mitosis are not.
104
Define linkage, and explain how linkage is used
to make gene maps.
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