Download Class XII biology Worksheet genetics and evolution

INDIAN SCHOOL MUSCAT
UNIT WISE BIOLOGY WORKSHEET
CLASS 12
UNIT VII. GENETICS AND EVOLUTION
1. What causes speciation according to Hugo de Vries?
2.
Name the parts ‘A’ and ‘B’ of the transcription unit given below. D ‘2008.
3’
1
1
Structural gene
A
3’
B
3.
Name the component ‘a’ and ‘b’ in the nucleotide with a purine, given below. D’2008
1
4.
Name the types of synthesis ‘a’ and ‘b’ occurring in the replication fork of DNA as shown
below. D’2008
1
5.
6.
Name any two vertebrate body parts that are homologous to human forelimbs? AI’08
Mention the polarity of the DNA a-b and c-d shown in the replicating fork given below. AI’08
1
1
7.
Mention the carbon positions to which the nitrogenous base and the phosphate molecule
1
are respectively linked in the nucleotide given below: AI’08
8.
9.
10.
11.
12.
13.
14.
15.
16.
17.
18.
19.
20.
21.
22.
23.
24.
25.
26.
27.
28.
29.
30.
31.
32.
33.
Why hnRNA is required to undergo splicing? D’09
Mention the type of evolution that has brought the similarity as seen in potato tuber and
sweet potato.D’09
Why are the wings of butterfly and of a bat called analogous? D’09
Mention the two additional processing which hnRNA needs to undergo after splicing so as
to become functional. D’09
According to Hardy-Weinberg’s principle the allele frequency of a population remains
constant. How do you interpret the change of frequency of alleles in a population? AI’09
When and at what end does the ‘tailing’ of hnRNA take place? AI’09
At which ends do ‘ capping’ and ‘tailing’ of hnRNA occurs respectively? F’09
A wing of a bird and the forelimb of a horse homologous or analogous? Name the type of
evolution that explains the development of such structures. F’09
Are flippers of penguin an dolphin homologous or analogous? What type of evolution has
brought such a similarity in them? F’09
Are the thorns of Bougain villea and tendrils of Cucurbita homologous or analogous? What
type of evolution has brought such a similarity in them? F’09
Mention two functions of the codon AUG D’10
Name the scientist who disproved spontaneous generation theory. D’10
Name one autosomal dominant and one autosomal recessive Mendelian disorder in
humans. AI’10
Name the enzyme involved in the continuous replication of DNA strand. Mention the
polarity of the template strand. AI’10
Write the genotype of i) an individual who is carrier of sickle cell anaemia gene but
apparently unaffected, and ii) an individual affected with the disease. AI’10
A human being suffering from Down’s syndrome shows trisomy of 21 st chromosome.
Mention the cause of this chromosomal abnormality. AI’10
Write the percentage of F2 homozygous and heterozygous populations in a typical
monohybrid cross. F’10
When does a species become founders to cause founder effect? F’10
A man with blood group A married a woman with B group. They have a son with AB blood
group and a daughter with blood group O. Workout the cross and show the possibility of
such inheritance. D’2008
The male fruit fly and female fowl are heterogametic while the female fruit fly and male fowl
are homogametic. Why are they called so? D’2008
What is divergent evolution? Explain taking an example of plants. D’2008
A plant of Antirrhinum majus with red flowers was crossed with another plant of the same
species with white flowers. The plants of the F1 generation bore pink flowers. Explain the
pattern of inheritance with the help of a cross. AI’08
A woman with blood group ‘O’ married a man with AB group. Show the possible blood
groups of the progeny. List the alleles involved in this inheritance. AI’08
How do Darwin’s finches illustrate adaptive radiation? AI’08
How is translation of mRNA terminated? Explain. D’09
Study the figure given below and answer the questions: D’09
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
2
2
2
2
2
2
2
2
a) How does the repressor molecule get inactivated?
b) When does the transcription of lac mRNA stop?
c) Name the enzyme transcribed by the gene ‘z’.
34. Explain the dual function of AUG codon. Give the sequence of bases it is transcribed from
and its anticodon. AI’09
35.
a) Name the molecue ‘X’ synthesized by ‘i’ gene. How does this molecule get
inactivated?
b) Which one of the structural genes codes for α-galactosidase?
c) When will the transcription of this gene stop? AI’09
36. Study the given portion of double stranded polynucleotide chain carefully. Identify a, b, c
and the 5’ end of the chain AI’09
d
2
2
2
OH
a
b
ee
c
37. Name the category of codon UGA belongs to. Mention another codon of the same category.
Explain their role in protein synthesis. F’09
2
38.
39.
40.
41.
42.
43.
44.
45.
46.
47.
48.
49.
50.
51.
52.
2
a) Name the molecule ‘ M’ that binds with the operator.
b) Mention the consequences of such binding.
c) What will prevent the binding of the molecule “M’ with the operator gene? Mention
the event that follows. F’09
Differentiate between a template strand and a coding strand of DNA. F’09
How is Darwin’s concept of evolution different from de Vries? F’09
How does a test cross help in identifying the genotype of the organism? Explain. D’10
When a tall pea plant was selfed, it produced one fourth of its progeny as dwarf. Explain
with the help of a cross. D’10
Mention the role of ribosomes in peptide bond formation. How does ATP facilitate it? AI’10
i)
Why are grasshopper and Drosophila said to show male heterogamety? Explain.
ii)
Explain female heterogamety with the help of an example. AI’10
Why are the wings of butterfly and birds said to be analogous organs? Name the type of
evolution of which the analogous organs are a result of. F’10
One of the codons on mRNA is AUG. Draw the structure of tRNA adapter molecule for this
codon. Explain the uniqueness of this tRNA. D’2008
Given below is a part of the template strand of a structural gene D/2008
TAC CAT TAG GAT
a) write its transcribed mRNA strand with its polarity.
b) Explain the mechanism involved in initiation of transcription of this strand.
Explain the pattern of inheritance of haemophilia in humans. Why is the possibility of a
human female becoming haemophilic extremely rare? Explain.D’2008
The length of the DNA molecule in a typical mammalian cell is calculated to be
approximately 2.2m. How is the packaging of this long molecule done to accommodate it
within the nucleus of the cell? D’2008
Explain the process of charging of tRNA. Why is it essential in translation? D’2008
A non-haemophilic couple was informed by their doctor that there is possibility of a
haemophilic child be born to them. Explain the basis on which the doctor conveyed this
information. Give the genotypes and the phenotypes of all the possible children who could
be born to them. D’2008
a)Draw the structure of the initiator tRNA adaptor molecule.
b) Why is tRNA called an adaptor molecule? AI’08
53.
2
2
2
2
2
2
2
3
3
3
3
3
3
3
3
Study the mRNA segment given above which is complete to be translated into a polypeptide
chain.
i)
Write the codons ‘a’ and ‘b’
ii)
What do they code for?
iii)
How is peptide bod formed between two aminoacids in the ribosomes? AI’08
54. Study the pedigree chart and answer the questions that follow.
3
I
II
III
a) Is the trait recessive or dominant?
b) Is the trait sex- linked or autosomal?
c) Give the genotypes of the parents in generation I and of their third and fourth child
in generation II. AI’08
55. How does Darwin theory of Natural selection explain the appearance of new forms of life on
earth? AI’08
56. Study the pedigree chart and answer the questions that follow:
I
3
3
II
III
a) Is the trait recessive or dominant?
b) Is the train sex- linked or autosomal?
c) Give the genotypes of the parents shown in generation I and their third child shown
in generation II and the first grand child shown in generation III. AI’08
57. Draw a labeled schematic sketch of replication fork of DNA. Explain the role of enzymes
involved in DNA replication. D’09
58. Haemophilia is a sex linked recessive disorder of humans. The pedigree chart given below
shows the inheritance of haemophilia in one family. Study the pattern of inheritance and
answer the questions given. D’09
3
3
a) Give all the possible genotypes of the members 4,5 and 6 in the pedigree chart.
b) A blood test shows that the individual 14 is a carrier of haemophilia. The member
numbered 15 has recently married the member numbered 14. What is the
probability that their first child will be haemophilic male?
59. Inhertiance pattern of ABO blood groups in humans shows dominance, codominance and
multiple allelism. Explain each concept with the help of blood group genotypes. D’09
60.
3
3
a) Mention the specific geographical region where these organisms are found.
b) Name and explain the phenomenon that has resulted in the evolution of such
diverse species in the region.
c) Explain giving reasons the existence of placental wolf and Tasmanian wolf sharing
the same habitat.
61.
3
a) What is this diagram representing?
b) Name the parts a, b and c.
c) In the eukaryotes the DNA molecules are organized within the nucleus. How is the
DNA molecule organized in a bacterial cell in absence of a nucleus? AI’09
62.
Recently a girl baby has been reported to suffer from haemophilia. How is it possible?
Explain with the help of a cross. AI’09
63. What is satellite DNA in a genome? Explain their role in DNA fingerprinting. AI’09
64.
3
a) Write your observations on the variations seen in the Darwin’s finches shown above.
3
3
b) How did Darwin explain the existence of different varieties of finches on Galapagos
Islands? AI’09
65. Draw a schematic representation of the structure of a transcription unit and show the
following in it:
i)
Direction in which the transcription occurs
ii)
Polarity of the two strands involved
iii)
Template strand
iv)
Terminator gene
b) Mention the function of promoter gene in transcription. AI’09
66.
a) In human genome which one of the chromosome has the most genes and which one
has the fewest?
b) Scientists have identified about 1.4 million single nucleotide polymorphs in human
genome. How is this information of their existence going to help the scientists? AI’09
67.
a) Identify the polarity from a’ to a, in the above diagram and mention how many more
aminoacids are expected to be added to this polypeptide chain.
b) Mention the DNA sequence coding for serine and the anticodon of tRNA for the same
amino acid.
c) Why are some untranslated sequences of bases seen in mRNa coding for a
polypeptide? Where exactly are they present on mRNA? F’09
68. In one family each of the four children has a different blood group. Their mother is group A
and the father is group B. Explain this pattern of inheritance with the help of a cross along
with the genotypes. F’09
69. Who proposed chromosomal theory of inheritance? Point out any two similarities in the
behaviour of chromosomes and genes. F’09
70.
What do these pictures ‘a’ and ‘b’ illustrate with reference to evolution? Explain. F’09
71. During his studies on genes in Drosophila that were sex-linked. T.H Morgan found F2
population phenotypic ratio deviated from expected 9:3:31. Explain the conclusion he
arrived at. D’10
72. Describe the initiation process of transcription in bacteria. D’10
73. Explain convergent and divergent evolution with the help of one example of each. D’10
74. Describe the elongation process of transcription in bacteria. D’10
75. Why are F2 phenotypic and genotypic ratios same in a cross between red-flowered
3
3
3
3
3
3
3
3
3
3
3
snapdragon and white-flowered snapdragon plants. Explain with the help of a cross. D’10
76. Describe the termination process of transcription in bacteria. D’10
77. In a series of experiments with Streptococcus and mice F.Griffith concluded that R-strain
bacteria had been transformed. Explain. AI’10
78.
a) How does the Hardy-Weinberg’s expression (p2+2pq+q2=1) explain that genetic
equilibrium is maintained in a population?
b) List any two factors that can disturb the genetic equilibrium. AI’10
79. Explain the sex determination mechanism in humans. How is it different in birds. AI’10
80. EExplain the mechanism of sex determination in insects like Drosophila and grasshopper.
AI’10
81. Workout a cross between true breeding red and white flowered dog-flower plants (
Snapdragon) up to F2 progeny. Explain the results of F1 and F2 generations. F’10
82. Inheritance pattern of flower colour in garden pea plant and snapdragon differs. Why is this
difference observed? Explain showing the crosses upto F 2 generation. D’09
83. Explain Hershey-Chase experiment. What was proved through this experiment? D’2008
84. a) A true breeding pea plant, homozygous for inflated green pods is crossed with another
pea plant with constricted yellow pods (ffgg).What would be the phenotype and genotype of
F1 and F2 generations? Give the phenotype ratio of F2 generation?
b) State the generalisation proposed by Mendel on the basis of above mentioned cross.
D’2008
85. A true breeding pea plant homozygous for axial violet flowers is crossed with another pea
plant with terminal white flowers (aavv)
a) What would be the phenotype and genotype of F1 and F2 generations?
b) Give the phenotypic ratio of F2 generations.
c) List the Mendel’s genralisation that can be derived from the above cross. D’2008
86. a)Explain Griffith’s experiments where he witnessed transformation in bacteria he worked
with.
b) Name the scientists responsible for detemining the biochemical nature of “transforming
priniciple” in Griffith’s experiments. What did they prove? D’2008
87. What is semiconservative DNA replication? How was it experimentally proved and by
whom? AI’08
88. A homozygous tall pea plant with green seeds is crossed with a dwarf pea plant with yellow
seeds.
i) What would be the phenotype of F1?
ii) Work out the phenotypic ratio of F2 generation with the help of a Punnett square. AI’08
89. A tall pea plant with yellow seeds (heterozygous for both the traits) is crossed with a dwarf
pea plant with green seeds. Using a Punnet square work out the cross to show the
phenotypes and genotypes of F1 generation.AI’08
90. a) Why is DNA molecule a more stable genetic material than RNA? Explain.
b) “unambiguous”, “degenerate” and “universal” are some of the salient features of genetic
codes. Explain. AI’08
91. Draw a labelled schematic structure of a transcription unit.Explain the function of each
component of the unit in the process of transcription. AI’08
92. A snapdragon plant homozygous for red flower when crossed with a white flowered plant of
the species produced pink flowers in F1 generation.
a) What is this phenotypic expression called?
b) Work out the cross to show the F2 generation when F1 was self pollinated. Give the
phenotype and genotypic ratios of F2 generation.
c) How do you compare the F2 phenotypic and genotypic ratios with those of Mendelian
monohybrid F2 ratios? AI’08
93. Two blood samples A and B picked up from the crime scene were handed over to the
forensic department for genetic fingerprinting. Describe how the technique of genetic
fingerprinting is carried out. How will it be confirmed whether the samples belonged to the
3
3
3
3
3
3
5
5
5
5
5
5
5
5
5
5
5
5
same individual or to two different individuals? D’09
a) Explain the experiment performed by Griffith on Streptococcus pneumoniae. What
did he conclude from this experiment?
b) Name thre three scientists who followed up Griffith’s experiments.
c) What did they conclude and how? D’09
95. How did Hershey and Chase prove that DNA is the hereditary material? Explain their
experiments with suitable diagrams. D’09
96.
a) Why did Meselson and Stahl observe when
i)
they cultured E.coli in a medium containing 15NH4Cl for a few generations and
centrifuged the content?
ii)
They transferred one such bacterium to the normal medium of 15NH4Cl and
cultured for 2 generations?
b) What did Meselson and stahl conclude from this experiment? Explain with the help
of diagrams.
c) Which is the first genetic material? Give support of your answer. D’09
97. You are given a red flower- bearing pea plant and a red flower-bearing snapdragon plant.
How would you find the genotypes of these two plants with respect to the colour of the
flower. Explain with the help of crosses. Comment upon the pattern of inheritance seen in
these two plants. D’09
98. How did Hershey and Chase prove that DNA is the hereditary material? Explain their
experiment with suitable diagram.
99. A particular garden pea plant produces only violet flowers.
a) Is it homozygous dominant for the trait or heterozygous?
b) How would you ensure its genotype? Explain with the help of crosses. AI’09
100.
a) How did Griffith explain the transformation of R strain ( non- virulent) bacteria into
S strain( virulent)?
b) Explain how MacLeod, McCarty and Avery determined the biochemical nature of
the molecule responsible for transforming R strain bacteria into S strain bacteria.
AI’09
101.
a) You are given tall pea plants with yellow seed whose genotypes are unknown. How
would you find the genotype of these plants? Explain the with the help of cross.
AI’09
b) Identify a, b and C in the table given below
Pattern of inheritance
Monohybrid F1 phenotypic
expression
94.
102.
1.
2.
Codominance
b
3.
Incomplete dominance
5
5
5
5
5
5
5
5
a
The progeny resembled only one of
the parents.
c
a) Explain the observations of Meselson and Stahl when
i)
they cultured E.coli in a medium containing 15NH4Cl for a few generations and
centrifuged the content.
ii)
They transferred one such bacterium to the normal medium of NH 4Cl.
b) What does the above experiment prove?
c) Which is the first genetic material identified? F’09
103.Inheritance pattern of flower colour in garden pea plant and snapdragon differs. Why is the
difference observed? Explain showing the cross. F’09
104.Explain the steps of DNA finger printing that will help in processing of the two blood
samples A and B picked up from the crime scene. F’09
105.A particular garden pea plant produced only violet flowers. It may or may not be
5
5
5
5
homozygous dominant for the trait. How would you ensure its genotype? Explain with
crosses. F’09
106.
i)
How does a chromosomal disorder differ from a Mendelian disorder?
ii)
Name any two chromosomal aberration associated disorders.
iii)
List the characteristics of the disorders mentioned above that help in their
diagnosis. D’10
107.Fitness is the end result of the ability to adapt and get selected by nature. Explain with
suitable example. D’10
108.Explain the causes, inheritance pattern and symptoms of any two Mendelian genetic
disorders. D’10
109.
i)
Natural selection operates when nature select for fitness. Explain .
ii)
The rate of appearance of new forms is linked to the lifespan of an organism.
Explain with the help of a suitable example. D’10
110.Write the symptoms of haemophilia and sickle cell anemia in humans. Explain how the
inheritance of the two diseases differs from each other. D’10
111.
a) Write the Hardy-Weinberg principle
b) Explain the three different ways in which natural selection can affect the
frequency of a heritable train in a population shown in the graph below. D’10
112.
a) State the law of independent assortment
b) Using Punnet Square demonstrate the law of independent assortment in a dihybrid
cross involving two heterozygous parents. AI’10
113.How did Alfred Hershey and Martha Chase arrive at conclusion that DNA is the genetic
material? AI’10
5
5
5
5
5
5
5
5