Download appendix ii - Shodhganga

APPENDICES
i
APPENDIX III
ACHIEVEMENT TEST – BOTANY
Class : XI
Division:
Duration: 2 hours
Marks : 50
I. Choose the correct answer:
(1x 30 = 30)
1. A stretch of chromosome that codes for a trait can be called a
a) Chromatid
b) replication fork
c) gene
d) base-pair
2. To which of these DNA strands would the DNA strand A-T-G-C-C-G-T-T
match?
a) G-C-A-T-T-A-C-C
b) C-G-T-A-A-T-G-G
c) T-A-C-G-G-C-A-A
d) T-T-G-C-C-G-T-A
3. Which of these sequences correctly describes how DNA is copied?
a) replication—bonding of bases—separation of strands—base pairing
b) separation of strands —base pairing—bonding of bases—replication
c) replication—bonding of bases—base pairing—separation of strands
d) separation of strands—bonding of bases—replication—base pairing
4. During replication, what enzyme adds complementary bases?
a) Helicase
b) Synthesase
c) Replicase
d) polymerase
5. A DNA strand has the following bases: A A G C C A. What are the bases on its
complementary strand?
a) A A G C C A
b) A C C G A A
c) T T C G G T
d) C C A T T C
6. Transcription results in :
a) an amino acid chain
b) messenger RNA
c) complementary DNA
d) Okazaki fragments
i
7. In RNA, _____ codons translate to ______ amino acids.
a) 1, 1
b) 3, 1
c) 3, 3
d) 1, 20
8. A nucleotide consists of:
a) a phosphate and a base
b) a phosphate, and a sugar
c) a base and an amino acid
d) a phosphate, a sugar, and a base
9. The enzymes that break hydrogen bonds and unwind DNA are:
a) primase
b) helicases
c) polymerases
d) ligase
10. If a DNA molecule is found to be composed of 40% thymine, what percentage
of adenine would be expected?
a) 10%
b) 20%
c) 40%
d) 80%
11. Attributes of the genetic code include all of the following EXCEPT:
a) Each codon consists of 3 nucleotides.
b) Each codon specifies more than one amino acid.
c) Codons are non-overlapping.
d) Most amino acids are coded for by more than one codon.
12. Which of the following statements regarding DNA structure is INCORRECT?
a) Adenine always pairs with thymine; and guanine pairs with cytosine.
b) The DNA helix has both major and minor grooves.
c) Base pairs are stabilized by salt bridges.
d) The two strands of a DNA helix are anti-parallel.
13. Okazaki fragments are
a) the pieces of DNA that result from DNA degradation.
b) the pieces of DNA that result from the interrupted synthesis of the
lagging strand of DNA during replication.
c) the pieces of RNA used to prime the replication of DNA by DNA
polymerase.
d) the pieces of DNA that are synthesized in the place of the RNA primer
during DNA replication.
ii
14. DNA polymerization occurs in
a) the 3’ to 5’ direction on both the leading and lagging strands.
b) the 5’ to 3’ direction on both the leading and lagging strands.
c) the 5’ to 3’ direction on the leading strands, and the 3’ to 5’ direction on
the lagging strands.
d) the 3’ to 5’ direction on the leading strands, and the 5’ to 3’ direction on
the lagging strands.
15. The mRNA codons of amino acids in a sequence of part of a polypeptide chain
are shown below. UGU-GAU-CAC-UAG-GAU-AAG-CAC . Which DNA
base sequence could provide the code for this section of polypeptide?
a) ACA-CTA-GTG-ATC-CTA-TTC-GTG
b) ACA-CTA-GTG-ATG-CTA-AAC-GTG
c) ACA-CTT-GTG-ATG-CTA-TTC-GTG
d) ACA-CUA-GUG-AUG-CUA-UUC-GUG
16. Which statement correctly describes the transcription of DNA?
a) It produces amino acids.
b) It produces messenger RNA.
c) It results in increased DNA synthesis.
d) It is a semi-conservative process.
17. What is the function of the enzyme DNA polymerase?
a) To build a strand of DNA using DNA as a template.
b) To build a strand of DNA using a polypeptide as a template.
c) To build a strand of mRNA using DNA as a template.
d) To build a strand of DNA using mRNA as a template.
18. What does a molecule of transfer RNA carry?
a) An amino acid molecule
b) Enzyme for protein synthesis
c) Information from the DNA
d) Sequence of codons.
19. Which statement describes the base pairing in nucleic acids?
a) Purine bases always pair with other purine bases.
b) Purine bases can only pair with pyrimidine bases.
c) Adenine cannot pair with either uracil or thymine.
d) Hydrogen bonding can only occur between the pyrimidine bases.
20. Which one of the following is NOT immediately essential for protein synthesis?
a) ATP
b) Enzyme
c) Glucose
d) mRNA
iii
21. What is the maximum number of possible amino acids which could be coded for
using the triplet code?
a) 3
b) 16
c) 48
d) 64
22. What is the advantage of DNA having two complementary strands?
a) Transcription and replication can occur simultaneously.
b) Semi-conservative replication is possible.
c) Diploid cells can inherit DNA from both parents.
d) Pyrimidines can form one strand and purines the other.
23. Which of the following base is never found in RNA?
a) Cytosine
b) Guanine
c) Uracil
d) Thymine
24. Adenine comprised 36% of the nitrogenous bases in the DNA of cells from a
bacterial clone. What was the percentage of guanine in the DNA?
a) 14% b) 18%
c) 36% d) 64%
25. Which of the following statements about the strands of a newly replicated DNA
molecule is correct?
a) Both strands are made up of newly assembled nucleotides.
b) One strand is new and the other is part of the original molecule.
c) Both strands contain some nucleotides from the original molecule.
d) The sugar-phosphate chains are conserved and new bases are inserted
between them.
26. Which of the following is involved in the inter-chain linkage between
complementary strands of DNA?
a) Covalent bonding between the sugar and nitrogenous bases
b) Covalent bonding between the sugar and the phosphate groups
c) Covalent bonding between adjacent sugar groups
d) Hydrogen bonding between the nitrogenous bases
27. If the nucleotide sequence of an anticodon was AUC, then the DNA triplet
would be
a) ATC
b) TAG
c) AUC
d) UAG
iv
28. If the code for an amino acid is AGC on the DNA molecule, the anticodon on
the tRNA would be
a) AGC
b) TGC
c) UCG
d) UGC
29. A section of DNA has the following sequence of nitrogenous bases:
CGATTACAG. Which of the following sequences would be produced as a
result of transcription?
a) CGTUUTCTG
b) GCTAATGTC
c) CGAUUACAG
d) GCUAAUGUC
30. DNA replication involves the breaking of bonds between
a) bases.
b) sugars and bases
c) phosphates and bases.
d) sugars and phosphates
II. Answer the following
31. The following base sequence represents part of a normal mRNA strand:
AUG–GGU–UCU–UAG
Write the sequence of amino acids coded for by the mRNA codons.
(2 marks)
Amino acids: ______________ - _______________ _______________ - _______________
32. Find out the mRNA sequence of codons that code for these amino acids.
(2 marks)
alanine - cysteine - leucine – phenylalanine
mRNA:
_______________ - _______________ _______________
-
_______________
v
33. You have isolated some double-stranded dinosaur DNA from a biting insect
preserved in fossilized amber. You then add the appropriate enzymes and
manage to transcribe a strand of mRNA from one of the DNA strands. Below is
the percentage composition of the bases for the DNA and m-RNA.
(2 marks)
DNA
Strand
1
DNA
Strand
2
mRNA
C
15
G
24
T
31
A
30
U
0
24
15
30
31
0
24
15
0
31
30
Which strand of DNA is the strand from which the mRNA was made? Explain.
34. Give the mRNA, DNA, and tRNA sequences that code for each of the following
amino acids. If there is more than one sequence, just give one.
(3 marks)
Aspartic acid
Valine
m RNA
DNA
t RNA
35. From a hospital patient afflicted with a viral disease, you isolate and culture
some cells and then extract the DNA. You find that the DNA from the culture
contains two different kinds of DNA, each placed in a different test tube: one is
double-stranded human DNA and the other is single-stranded virus DNA. You
analyze the percent base composition of the two DNA extracts with the
following results.
Tube 1
Tube 2
A
22
35
C
28
15
G
28
30
Which tube contains the single-stranded viral DNA? Explain.
T
22
20
(3 marks)
vi
36.
From an extract of human cells growing in tissue culture, you obtain a white
fibrous substance. By noting the differences in chemical structure, building
blocks, etc. list the features by which you could distinguish whether it was
DNA, RNA, or protein.
(3 marks)
DNA
RNA
PROTEIN
37. Describe, with the help of suitable diagrams, the steps in protein synthesis,
beginning with the attachment of a messenger RNA molecule to the small
subunit of a ribosome and ending with the release of the polypeptide from the
ribosome. Include in your answer a discussion of how the different types of
RNA function in this process.
(5 marks)
vii
APPENDIX IV
Sl.No:
1.
2.
3.
4.
5.
6.
7.
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.
SCORING KEY AND MARKING SCHEME
Expected Outline Answers
Marks allotted
to each point
C
1
1
C
1
B
1
D
1
C
1
B
1
B
1
D
1
B
C
1
1
B
1
C
1
B
1
B
1
A
1
B
1
A
1
A
1
B
1
C
1
D
1
B
1
D
D
1
1
B
1
D
1
A
1
A
1
D
A
1
Methionine
Glycine
Serine
Stop codon
½
½
½
½
GCU/GCC/GCA/GCG
UGU/UGC
UAA/UUG/CUU/CUC/CUA/CUG
UUU/UUC
½
½
½
½
Total
Marks
30
2
2
i
33.
34.
DNA 1
½
Anti-sense strand, complementary
to m-RNA strand
1½
Aspartic acid- m-RNA: GAU/GAC
DNA: CTA/CTG
tRNA: CUA/CUG
½
½
½
2
3
Valine- mRNA:
GUU/GUC/GUA/GUG
DNA:
CAA/CAG/CAT/CAC
½
½
½
tRNA:CAA/CAG/CAU/CAC
35.
36.
37.
Tube 2
½
A not equal to T and C not equal to
G in single stranded DNA
1½
DNA-nucleotides are the building
blocks, contains deoxyribose sugar,
bases A,T,G and C and phosphate.
Double stranded
1
RNA- nucleotides are the building
blocks, contains ribose sugar, bases
A,U,G and C and phosphate.
Single stranded
1
Proteins- amino acids are the
building blocks, linked by peptide
bonds forming polypeptides.
1
3
3
Translation takes place in the
cytoplasm.
Initiation(i)
mRNA binds to small
subunit of ribosome in
ii
(ii)
(iii)
(iv)
(v)
presence of initiation
factors.
initiator codon AUG on
mRNA binds with small
subunit forming initiation
complex.
Then larger subunit
(having the P-site and Asite) binds.
First aminoacyl tRNA
binds to P-site. Initiation
factors are released.
Second aminoacyl tRNA
binds to A-site followed
by peptide bond
formation (enzymepeptidyl
transferase)between the
two amino acids.
2½
Elongation(i)
Ribosome moves to
adjacent codons on
mRNA (translocation -by
translocase enzyme) and
the process continues.
5
1½
Termination- on finding the stop
codons
Diagram-
1
Types of RNA:
mRNA: where ribosome binds to
bring about protein synthesis.
t RNA helps to bring the amino
acids to the site of protein synthesis.
rRNA : needed for the synthesis of
ribosomes
iii
APPENDIX V
RATING SCALE FOR TEACHERS
Sir/ Madam,
This rating scale is meant for collecting your views regarding the availability of
resources, extent of use and need for special training to teachers for using
Computer Assisted Instruction (CAI) and Constructivist Model (CM) in
classrooms. Kindly record your
y
opinion by a
mark in the appropriate column.
A. Availability of Resources
1. For CAI
Sl.No:
Aspects
(i)
Availability of computers in your school
(ii)
Internet facility in your school
(iii)
Availability of computer assisted lessons
(iv)
Availability of suitable literatures
development of educational softwares
for
GE
SE
NA
GE
SE NA
GE
SE NA
GE
SE NA
the
2. For Constructivist Model
Sl.No:
Aspects
(i)
Availability of suitable resources
(ii)
Availability of suitable support systems
(iii)
Availability of literatures and reference materials for
preparing constructivist lessons
B. Extent of Use
Extent of Use
(i)
Of CAI in teaching Biology
(ii)
Of Constructivist Model in teaching Biology
C. Need for Special training
Sl.No: Need for training to teachers for teaching Biology
(i)
Using CAI
(ii)
Using Constructivist Model
i
APPENDIX VI
QUESTIONNAIRE FOR TEACHERS
Sir / Madam,
This Questionnaire is meant to find out the practical difficulties
likely to be encountered by teachers while using Computer Assisted
Instruction and Constructivist Model in classrooms.
Rank in order the practical difficulties likely to be encountered by
teachers if the methods (CAI and CM) are adopted in classrooms as teachinglearning strategy.
Sl.No:
Practical difficulties
i.
Rigid timetable
ii.
Overcrowded classrooms
iii.
Lack of structure within the classes
iv.
Consumption of time
v.
Inadequate reference/ library facilities
vi.
Unavailability of suitable resource materials
vii.
Inadequate knowledge of the method of instruction
viii.
Unfamiliarity with the theory underlying the
models
ix.
Overloaded syllabus
x.
Lack of cooperation from authorities
xi.
Lack of cooperation from colleagues
xii.
Lack of cooperation from parents
xiii.
Lack of training
xiv.
Defective examination system
xv.
Greater challenge to teachers
Rank in order
of difficulty
CAI
CM
Any other:
Please give your suggestions for the effective implementation of the two
methods (CAI and CM) in teaching Biology.
APPENDIX II
CONSTRUCTIVIST MODEL LESSON-I
Name
: Jisha Rose Mary Joseph
Subject
: Biology
Unit
: Molecular Genetics
Lesson Unit: Structure of DNA
Name of School:
Standard
: XI
Date
:
Instructional Objectives:
The pupil
I. Remembers the terms - DNA backbone, deoxyribose sugar, nitrogenous bases, Base-Pair Rule, Nucleoside, Nucleotide and related facts.
II. Acquires Understanding of the above said terms and related facts.
III. Develops ability to Apply the knowledge in the class.
i. Pupil is able to construct a DNA strand by relating the bases, sugars and phosphate groups.
IV. Develops ability to Analyse the learned facts and concepts.
i. Pupil is able to identify the four nitrogenous bases and sugar present in DNA.
ii. Pupil is able to identify the two base pairs of DNA.
iii. Pupil is able to analyse the structure of DNA .
V. Develops ability to Evaluate the learned facts and concepts.
i.
Pupil is able to differentiate the nitrogenous bases, sugar and phosphate groups and form the structure of DNA
VI. Develops ability to Create the learned facts and concepts.
i.
Pupil is able to create the model of DNA using the materials provided.
i
Phases
Activities/ Interactions
Displays/ Resources Used
Engage
Teacher reads a news report that explains a crime that has been
committed and the criminal is unknown. It is also stated that DNA
samples have been picked up at the scene and a DNA test will help
find the criminal. Why is a DNA test a possible way to find the
criminal?
Student makes the suggestion that DNA of every individual is
unique.
News report
Explore
Students are divided into groups of three each. Teacher asks the
students to read the relevant area in the text.
Student reads the relevant section in the text and each group
discusses on what DNA is.
Text book
Teacher asks questions to the students on what they know about
DNA.
Students give the responses in the response sheet
Discusses about the basic knowledge on DNA.
Student response sheet
Teacher gives the following guiding questions. Taking the pictures
of DNA as reference and based on what they understood from
reading the text, the students are asked to give their responses on the
sheet of paper provided.
What are the components of DNA?
Sugar, nitrogen bases and phosphates
Response sheet / Notebook
Two pictures of DNA, on showing the helical structure ad
the other showing the arrangement of nucleotides
Explain
What is the structure of DNA?
A DNA molecule is formed of two long chains or backbones and
four types of Nitrogen bases.
ii
What forms the DNA backbone?
The DNA backbone is formed of a chain of alternating sugars and
phosphate groups. Each sugar molecule is joined at the 3’ and 5’
hydroxyl groups to the phosphate groups through ester links called
phosphodiester bonds.
Response sheet/ note book
Name the sugar present in DNA.
Deoxyribose.
How many bases are present in DNA?
Four bases
Which are the bases present?
Adenine(A), Thymine(T), Guanine (G) and Cytosine(C)
How do the bases differ?
Adenine and Guanine are formed of two fused rings and are called
purines. Cytosine and Thymine are single ringed structures and are
called pyrimidines.
How do the bases pair?
The bases pair in a specific manner by hydrogen bonds.
What is the Base-Pair Rule?
Adenine always pairing with Thymine by two H-bonds and Cytosine
always pairing with Guanine by three H-bonds. This is called the
Base-Pair Rule.
How is the base pair attached to the DNA backbone?
Each base in the base-pair is also connected to a sugar molecule in
the DNA backbone.
iii
What is a nucleoside?
A Nitrogen base covalently attached to a sugar molecule is a
nucleoside.
Response sheet /Notebook
What is a nucleotide?
A deoxyribose sugar, a N-base and a phosphate group together form
a nucleotide.
Which is the basic unit of DNA?
Nucleotide
Referring to Pic.2, teacher asks, What is the peculiarity about the
structure of DNA?
Does it resemble any object ?
DNA looks like a twisted ladder. The base pairs form the rungs or
steps of the ladder and the sugar-phosphate backbone forms the
sides of the ladder.
How do the two chains of DNA differ?
They run in opposite directions.(anti-parallel)
Now do you know why the DNA of every individual is unique?
Because of the characteristic base pairing
How does the DNA vary among individuals?
Changing the position of base pairs allows for infinite number of
sequences to occur
Teacher walks around and uses individual interventions to provide
guidance.
iv
Elaborate
Evaluate
Teacher discusses the responses of the students and uses group
intervention to reinforce concepts or instructions that have surfaced
from individual questions or interventions.
Teacher asks the students to make their models of DNA using the
materials provided.
Student makes the DNA model from the materials given.
Materials provided include
2 black wires, 12 red beads, 12 green beads, 12 blue beads,
12 yellow beads, toothpicks
[The 2 black wires serve as DNA backbone,
Beads represent the four bases, red-A, blue-T., green-C and
yellow- G.
Toothpicks show the H-bonds between the base-pairs.]
Homework exercise is given. Student completes it for the next day
Home work exercise
Since this is a constructivist lesson, it purposely does not review and
link the new concept to old concepts—it was left to the students to
do the initial linking. Students were allowed to give their responses
based on what they understood and later group interventions were
used to reinforce the concepts. Students were asked to construct the
DNA model based on their knowledge of DNA.
Review
1. What is the difference between nucleotide and nucleoside?
2. How does DNA vary among individuals?
Follow up Activity
1. A sequence of 15 bases is given. AUGCATTGATTCGAC. Construct a DNA molecule using materials of your choice.
2. Draw a double helical structure of DNA and label it neatly.
3. Find out the different types of DNA and the features of each.
v
CONSTRUCTIVIST MODEL LESSON-II
Name
: Jisha Rose Mary Joseph
Subject
: Biology
Unit
: Molecular Genetics
Lesson Unit: Replication of DNA
Name of School:
Standard
: XI
Date
:
Instructional Objectives:
The pupil
I.
Remembers the terms - DNA replication, semi-conservative mode, replication origins, replication bubble, replication fork, DNA
polymerase, helicase, single strand binding proteins, primase, exonuclease, DNA ligase, topoisomerase, leading strand, lagging strand,
Okazaki fragments and related facts and concepts.
II.
Acquires Understanding of the above said terms and related facts and concepts.
III.
Develops ability to Apply the knowledge in the class.
i. Pupil is able to construct the model showing DNA replication.
ii. Pupil is able to show how the basic structure of DNA is important in the process of DNA replication.
IV.
Develops ability to Analyse the various steps involved in DNA replication.
V.
Develops ability to Evaluate the learned facts and concepts.
i.
Pupil is able to summarise the role of various enzymes involved in DNA replication.
VI.
Develops ability to Create the learned facts and concepts.
i. Pupil is able to relate the enzymes involved with their role, in DNA replication.
ii. Pupil is able to explain the importance of DNA strand separation.
vi
Phases
Activities/ Interactions
Displays/ Resources Used
Engage
An embryonic cell divides again and again. Where there was one
cell, there are two, then four, then eight and so on….Each holds the
genetic information needed to create a new human being. How
exactly do these cells make copies of themselves?
As cells divide, DNA is passed on from the parent cells to the
daughter cells.
Text book
So, now let’s see how the DNA passes from the parent cell to the
daughter cells.
Explore
Students are divided into groups of three each. Teacher asks the
Text book and Response sheets
students to read about DNA replication and Meselson-Stahl
Experiment from the text. To make sure they understand how
replication works, teacher tells the students to write down interesting
points in a paper while reading and makes sure they are
understanding the main ideas.
Explain
Teacher asks questions to link previous knowledge of the students
with what is to be learned. Student writes the answers in the
response sheet.
Response Sheet
Chart showing semi-conservative, conservative and
dispersive replication
What do you think DNA does when cell divides?
DNA divides.
Does each new cell contain DNA?
Yes.
Where does this extra DNA come from?
From the parent cell.
vii
How does DNA make copies of themselves?
By replication
What is meant by DNA replication?
DNA replication is the process by which a double-stranded DNA
molecule makes a copy of itself.
Teacher asks the following guiding questions. Student writes the
answers in the response sheet/ note book.
Why does DNA replicate?
The basis of life is built on the ability of the cells to replicate with
identical blueprints for survival. DNA replication provides the
foundation of this process.
Response sheet / Notebook
Do the base-pairing rules for replication match the base-pairing rules
learned in the previous class? Yes
What is the type of replication? Semi-coservative
Why is it so called?
When the replication process is complete, two DNA molecules identical to each other and identical to the original - have been
produced. This mode of replication is described as
semiconservative: one-half of each new molecule of DNA is old
and one-half new.
How is the basic structure of DNA important in the process of
replication?
The daughter DNA produced are exactly similar to the parent DNA.
Teacher walks around and uses individual interventions to provide
guidance.
viii
Elaborate
Teacher discusses the responses of the students and uses group
intervention to reinforce concepts or instructions that have surfaced
from individual questions or interventions.
Teacher asks the students to demonstrate replication with the help of
the DNA model prepared in the previous class.
From the DNA model prepared in the previous class, student will
show how replication occurs. Old strands are marked with tape so
that the student can tell what happens to the different strands.
Replication models are made by breaking the toothpicks (H-bonds)
between the base-pairs and by creating two new strands
complementary to the old strands following the base-pair rule.
Teacher gives additional information about the mechanism of DNA
replication and the role of various enzymes involved in it.
Evaluate
Materials needed to demonstrate replication of DNA (Blue
wires, tooth picks, coloured beads-red, blue, green and
yellow, scissors, tape and the DNA model prepared in the
previous class) are given to each group
Since this is a constructivist lesson, it purposely does not review and
link the new concept to old concepts—it was left to the students to
do the initial linking. Students were allowed to give their responses
based on what they understood and later group interventions were
used to reinforce the concepts. Students were asked to show DNA
replication using the DNA model prepared in the previous class.
Review
1. What is meant by replication of DNA?
2. Why is DNA replication called semi-conservative?
Follow-up Activity
1. Read the mechanism of DNA replication from the text book and explain the steps involved in the replication of DNA.
ix
CONSTRUCTIVIST MODEL LESSON-III
Name
: Jisha Rose Mary Joseph
Subject
: Biology
Unit
: Molecular Genetics
Lesson Unit: RNA-Structure, Types and Functions
Name of School:
Standard
: XI
Date
:
Instructional Objectives:
The pupil
I.
II.
III.
IV.
V.
VI.
Remembers the terms - Ribose sugar, Uracil, messenger RNA (m-RNA), ribosomal RNA (r-RNA) and Transfer RNA (t-RNA)
Acquires Understanding of the above said terms and related facts and concepts.
Develops ability to Apply the knowledge in the class.
i. Pupil is able to construct the model of RNA.
Develops ability to Analyse the learned facts and concepts.
i. Pupil is able to identify the four nitrogenous bases and sugar present in RNA.
ii. Pupil is able to analyse the structure of RNA .
Develops ability to Evaluate the learned facts and concepts.
i. Pupil is able to compare and contrast the different types of RNA based on their structures and functions.
Develops ability to Create the learned facts and concepts.
i. Pupil is able to create an RNA strand if a DNA strand is given.
x
Phases
Activities/ Interactions
Displays/ Resources Used
Engage
Teacher shows the coloured pictures of DNA and RNA.
Coloured pictures of DNA and RNA
Explore
Students are divided into groups and each group is asked to refer to
the pictures and identify and write down the similarities and
dissimilarities between the structure of DNA and RNA.
Teacher asks the students to read the relevant area in the text book
and write down the points which they feel interesting in their note
books.
Text book and Response sheet/ Note book
Explain
Teacher asks questions to activate the prior knowledge of students.
What are the two chemical differences between RNA and DNA?
In RNA, the sugar is ribose and the base Uracil(U) is present in
place of Thymine(T).
Response sheet
What are the characteristics of genetic material?
Should reproduce and be transmitted faithfully from generation to
generation.
Should be structurally and chemically stable.
Should be able to express itself.
Should be capable of changing by mutation.
Teacher asks several guiding questions. Student writes the answers
in the response sheet / notebook
Does RNA fulfill all the characteristics of a genetic material? Let’s
take them one by one.
Response sheet / Note book
Is RNA capable of making copies?
Yes
Is RNA stable?
xi
RNA is easily degradable (because of the 2’-OH group present in
every nucleotide).RNA is also catalytic and hence more reactive.
RNA is less stable than DNA.
Is RNA capable of expressing itself?
RNA can directly code for proteins.
Is RNA capable of mutating?
RNA being less stable mutate faster.
Which do you think is a better genetic material-DNA or RNA?
DNA and RNA function as genetic material but DNA being more
stable helps in the storage of genetic information while RNA helps
in the transmission of genetic information.
Which is the first genetic material?
RNA.
Why is RNA considered as the first genetic material?
Essential life processes evolved around RNA. RNA acted as a
genetic material as well as a catalyst in various biochemical
reactions. But being a catalyst, RNA was reactive and unstable.
Therefore, DNA has evolved from RNA.
How does the structure of RNA affect its function?
Being single stranded, RNA is able to complement itself and form
tertiary structures. Tertiary structure of RNA plays a crucial role in
determining its function.
Which are the three main types of RNA?
Messenger RNA (m-RNA), ribosomal RNA (r-RNA) and Transfer
RNA (t-RNA)
xii
What are functions of m-RNA, r-RNA and t-RNA?
messenger RNA (mRNA)- encode proteins needed for the function
of a particular cell (e.g., the mRNA for haemoglobin in the
precursors of red blood cells).
ribosomal RNA (rRNA)- Is used in the building of ribosomes which
form the machinery for synthesizing proteins by translating mRNA.
transfer RNA (tRNA)- RNA molecules that carry amino acids to the
growing polypeptide.
Teacher shows a chart on the structure of t-RNA and asks students
to explain its structure. Teacher gives help whenever needed.
Chart - Structure of t-RNA
Teacher walks around and uses individual interventions to provide
guidance.
Elaborate
Teacher discusses the responses of the students and uses group
intervention to reinforce concepts or instructions that have surfaced
from individual questions or interventions.
Teacher asks the students to make a model of RNA using the
materials provided. Student makes RNA model using the materials.
Evalute
Each group is given materials to make their RNA model.
(Red wires, tooth picks, coloured beads-red, orange, green
and yellow) Red wires serve as sugar-phosphate backbone,
Beads represent the four bases, red-A, orange-U., green-C
and yellow- G.
Toothpicks- to join the bases with the sugar-phosphate
backbone.
Since this is a constructivist lesson, it purposely does not review and
link the new concept to old concepts—it was left to the students to
do the initial linking. Students were allowed to give their responses
based on what they understood and later group interventions were
used to reinforce the concepts. Students were asked to make a model
of RNA using the materials provided.
xiii
Review:
1. Why is DNA considered a predominant genetic material?
2. What are the three main types of RNA? Mention their functions.
3. Differentiate between RNA and DNA
Follow-up Activities.
1. Find out more about the different types of RNA and their functions.
2. Make a model of RNA
xiv
CONSTRUCTIVIST MODEL LESSON-IV
Name
: Jisha Rose Mary Joseph
Subject
: Biology
Unit
: Molecular Genetics
Lesson Unit: Transcription
Name of School:
Standard
: XI
Date
:
Instructional Objectives:
The pupil
I. Remembers of the terms- Gene expression, Central Dogma, Transcription, Anti-sense strand and related facts and concepts.
II. Develops Understanding of the above said terms and related facts and concepts.
III. Develops ability to Apply the knowledge in the class.
i. Pupil is able to construct the model showing transcription.
IV. Develops ability to Analyse the learned facts and concepts.
i. Pupil is able to analyse the steps involved in transcription.
V. Develops ability to Evaluate the learned facts and concepts.
i. Pupil is able to identify that transcription is an important step in protein synthesis.
VI. Develops ability to Create the learned facts and concepts.
i. Pupil is able to organise in order the steps involved in transcription.
xv
Phases
Activities/ Interactions
Displays/ Resources Used
Engage
Hair grows from your head, non-stop, day in and day out. The cells
of your hair follicles somehow generate all of the protein that make
up this hair. How is this protein created?
Text book/Resource material
Today, we shall learn how this protein is created. First, we shall
learn about transcription , which is the process in which DNA is
copied by m-RNA and try to create a model of transcription.
Explore
Students are divided into groups of three each. Teacher asks the
students to read the relevant area in the text. To make sure they
understand, teacher tells the students to write down interesting
points in a paper while reading.
Text book and Response sheets
Materials to demonstrate the processes of transcription ,namely the
prepared DNA model, One red wire, red beads, green beads, yellow
beads ,orange beads, toothpicks, scissors, tape ,etc are given to each
group.
Explain
Teacher uses guided inquiry to activate the prior knowledge of
students. Students are asked to write their responses in the response
sheet.
What happens during the process of cell division?
DNA is replicated and new cell structures are formed.
Response Sheet
What are the new cell structures made of?
Proteins.
Who gives the information for the synthesis of proteins?
Genes located on DNA.
xvi
What do genes code for? Proteins
What is the role of proteins in the cell?
Give structure to the cell and do functions in the cell
Which are the sites of protein synthesis? Ribosomes
Where are ribosomes located? In the cytoplasm
Where are genes located? On the DNA inside the nucleus.
How does the genetic information get out of the nucleus?
Information in the DNA is copied by the m-RNA and this m-RNA
moves into the cytoplasm through the nuclear pores.
Showing a simple flowchart of the steps in gene expression, teacher
asks,
How do the genes provide the cell with information necessary for
protein synthesis? Or, how are the genes expressed? Or, How do
cells use DNA to make proteins? Sequence of DNA is copied
enzymatically to produce a complementary RNA strand, called
messenger RNA (mRNA), which in turn is passed into the
cytoplasm to be translated to proteins.
What is meant by gene expression?
Gene Expression is the process by which information contained in
the gene (DNA) is converted into molecules (proteins) that
determine the properties of the cell.
Flowchart showing the steps in gene expression
What are the steps involved in Gene Expression?
Gene expression occurs in two steps:
•
Transcription = DNA → RNA
xvii
•
Translation = RNA → protein.
Showing a simple figure of Central Dogma, teacher asks, What is
meant by the Central Dogma of Molecular Biology?
Chart on Gene Expression and Central Dogma of
Molecular Biology
DNA in the nucleus is first copied into a single stranded molecule
called RNA which travels out of the nucleus into a protein and do
work and provide structure to the cell.
Transcription and Translation together make up the central dogma
of molecular biology: DNA → RNA → protein.
Teacher shows the analogy: Blueprint of a house, engineer,
To help understand Central Dogma in terms of what the students
already know, teacher shows an analogy of Central dogma, and asks, land, materials for building the house(bricks, cement, iron
rods, paint,etc.),workers (masons, carpenters, painters,etc.),
How can you compare the analogy with the Central Dogma
picture of house.
Student compares the symbols that best describe the functions of the
bio-molecules. Blueprint of the house is compared to DNA,
Engineer to m-RNA, land where the house is to be built to the
ribosomes, workers to the t-RNA, materials to amino-acids, and
picture of the house to proteins.
Teacher continues with the following questions. What is
transcription? Transcription is the process by which genetic
information stored in a strand of DNA is copied into a strand of
RNA.
What are the steps involved in transcription?
Separation of the DNA strands and Synthesis of an m-RNA strand in
the 5’ to 3’ direction on one of the DNA strand known as the anti-
xviii
sense strand.
Does a particular gene transcribe its m-RNA in different amounts at
different times? Yes, Cells can regulate the amount of proteins.
Teacher walks around and uses individual interventions to provide
guidance.
Elaborate
Teacher discusses the responses of the students and uses group
intervention to reinforce concepts or instructions that have surfaced
from individual questions or interventions.
Teacher writes a sequence of nucleotides on the black board and
asks the students to make their model of transcription with the help
of the materials provided, taking hints from what they have
understood.
Student makes models of transcription using the materials.
Transcription:DNA m-RNA
Step 1: Unzipping the DNA.
Cells copy only one side of the DNA ladder. In order to make this
copy, the chemical bases forming the rungs of the DNA ladder must
be separated.
• Cut or break in the middle the toothpicks in the model to separate
the chemical bases and unzip the DNA ladder.
• Set the unlabelled backbone with chemical bases attached aside.
Step 2: Begin to form the mRNA strand.
The exposed chemical bases, or nucleotides of the unzipped DNA
(DNA 1 or 2) are used to make the copy. This copy is called
messenger RNA (mRNA). The chemical bases in mRNA form pairs.
Adenine (A) binds with Uracil (U) and Guanine (G) binds with
Cytosine (C).
Materials include: DNA model made during the first class,
a red wire,
12 red beads
12 green beads
12 blue beads
12 yellow beads
12 orange beads
toothpicks
The red wire serves as RNA backbone, beads represent the
bases, red-A, blue-T, green-C and yellow- G and orange-U,
Toothpicks show the H-bonds between the base-pairs.
xix
• Place the backbone labelled “DNA-1” or “DNA-2” depending on
which one to make the model.
• Follow the rules of base pairing to make the mRNA copy of the
DNA code by lining up coloured beads with their appropriate match.
Step 3: The chemical bases of mRNA are also attached to a
backbone as in DNA.
• Attach the new chemical bases to the red wire backbone using
toothpicks cut or broken in half. This forms a new mRNA copy of
the DNA strand.
• Label this new strand mRNA-1 or mRNA-2 on the left end of the
backbone.
Evaluate
Since this is a constructivist lesson, it purposely does not review and
link the new concept to old concepts—it was left to the students to
do the initial linking. Students were allowed to give their responses
based on what they understood and later group interventions were
used to reinforce the concepts. Students were asked to show
transcription using the materials provided.
Review
1. Write a DNA sequence and make a complementary RNA of it
2. What are the steps involved in transcription?
3. What is meant by Central Dogma of Molecular Biology?
Follow up Activities:
1. Draw and neatly label Central Dogma of Molecular Biology.
2. Draw a diagram showing transcription.
3. Briefly explain the process of transcription with suitable labeled diagrams.
xx
CONSTRUCTIVIST MODEL LESSON-V
Name
: Jisha Rose Mary Joseph
Subject
: Biology
Unit
: Molecular Genetics
Lesson Unit: Structure of DNA
Name of School:
Standard
: XI
Date
:
Instructional Objectives:
The pupil
I.
II.
III.
IV.
V.
VI.
Acquires Remembrance of the terms - Translation, Aminoacylation of t-RNA, Initiation, Elongation , Termination,
Genetic code chart, codon, anticodon and related facts.
Acquires Understanding of the above said terms and related facts and concepts.
Develops ability to Apply the knowledge in the class.
i. Pupil is able to construct the model showing translation.
ii. Pupil is able to describe the process of protein synthesis.
Develops ability to Analyse the learned facts and concepts.
i. Pupil is able to analyse the steps involved in translation.
Develops ability to Evaluate the learned facts and concepts.
i. Pupil is able to recognize the importance of protein synthesis.
Develops ability to Create the learned facts and concepts.
i. Given a “code”, pupil is able to determine the amino acid sequence.
ii. Pupil is able to organise in order the steps involved in translation.
xxi
Phases
Activities/ Interactions
Displays/ Resources Used
Engage
How do cells synthesise the proteins it require?
Messenger RNA (mRNA) copied from DNA, in turn passes into the
cytoplasm and gets translated to proteins.
Text book and Response sheet/ Note book
Explore
Students are divided into groups of three each. Teacher asks the
students to read the relevant area in the text. To make sure they
understand, teacher tells the students to write down interesting
points in a paper while reading. Materials to demonstrate the
processes of transcription namely, prepared m-RNA strand, large
oval cut-outs, coloured circle cut-outs, cresent shaped cut-outs.
Teacher also introduces the Genetic code chart and helps the
students to read it.
Text book and Genetic code chart
Student response sheet
Student reads the relevant area and notes down interesting facts.
Also learns to read the Genetic Code chart
Explain
Teacher asks questions to link the prior knowledge of students with
what is to be learned. Student writes the responses in the response
sheet.
What do genes code for? Proteins
Response sheet
What is the role of proteins in the cell? Give structure and do
functions in the cell
Which are the sites of protein synthesis? Ribosomes
Where are ribosomes located? In the cytoplasm
Where are genes located? On the DNA inside the nucleus.
xxii
How does the genetic information get out of the nucleus?
DNA strand is copied enzymatically to produce a
complementary RNA strand, called messenger RNA (mRNA),
which in turn is passed into the cytoplasm to be translated to
proteins.
Which is the second step in the Central Dogma of Molecular
Biology? Translation.
What is translation? The process by which information in m-RNA
gets translated into proteins is called translation.
Teacher asks the following questions and students write their
responses in the response sheet.
Response sheet / Notebook
Does m-RNA travel to different parts of the cell to be translated?
Proteins are made where they are needed in the cell.
Are new proteins synthesized at all times in the cell?
New proteins are produced at all times to support the life processes
of the cell.
How is m-RNA read?
m-RNA is read in groups of three nucleotides or bases. Each group
of three bases tells the cell which amino acid to assemble.
What are the steps involved in translation?
Charging of t-RNA (Aminoacylation of t-RNA)
Initiation
xxiii
Elongation
Termination
What is meant by charging of t-RNA?
The amino acids are activated in presence of ATP and linked to their
appropriate t-RNA by an activating enzyme specific for that amino
acid as well as for the t-RNA assigned to it.
What do you know about the structure of t-RNA?
t-RNA looks like a clover-leaf.
Each tRNA also called soluble RNA(sRNA)has a sequence of 3
unpaired nucleotides - the anticodon - which can bind, following the
rules of base pairing, to the complementary triplet of nucleotides the codon - in a messenger RNA (mRNA) molecule. Just as DNA
replication and transcription involve base pairing of nucleotides
running in opposite direction, so the reading of codons in mRNA (5'
3') requires that the anticodons bind in the opposite direction.
Anticodon: 3' CGG 5'
Codon : 5' GCC 3'
It also has an aminoacid acceptor arm to which it binds to
aminoacids.
The aminoacid for the particular t-RNA is Alanine.
There are no t-RNAs for stop codons.
What happens during initiation?
Initiator tRNA carrying methionine binds to the P site of the
ribosome where it has encountered the start codon AUG.
How does elongation of the peptide chain take place?
An aminoacyl-tRNA (a tRNA covalently bound to its amino acid)
xxiv
able to base pair with the next codon on the mRNA arrives at the A
site. The preceding amino acid (Met at the start of translation) is
covalently linked to the incoming amino acid with a peptide bond.
The initiator tRNA is released from the P site. The ribosome moves
one codon downstream. This shifts the more recently-arrived tRNA,
with its attached peptide, to the P site and opens the A site for the
arrival of a new aminoacyl-tRNA and the process goes on and on.
How do protein synthesis terminate?
The end of translation occurs when the ribosome reaches one or
more STOP codons (UAA, UAG, UGA). No t-RNA enters the Asite. When the stop codon is reached the ribosome falls off the
mRNA and translation stops.
Teacher walks around and uses individual interventions to provide
guidance.
Elaborate
Teacher discusses the responses of the students and uses group
intervention to reinforce concepts or instructions that have surfaced
from individual questions or interventions.
Teacher asks the students to make a model of translation using the
materials provided.
Materials :
Prepared m-RNA strand ,
large oval cut-outs representing ribosomes,
coloured circle cut-outs representing t amino acids,
cresent shaped cut-outs representing t-RNAs, tape, Genetic
code chart,etc
Finally, Teacher asks to record the results in their notebooks.
Notebook
1) What was the initial DNA sequence?
xxv
2) What was the mRNA sequence?
3) What were the amino acids that made up the protein sequence?
Finally, teacher gives an activity to the students to display their
understanding of the process of protein synthesis. Activity will help
student to display his understanding of the process of protein
synthesis.
Students work in groups.
Materials required:
•
•
5 DNA Template Cards: these will be kept on the
desk at all times since DNA cannot leave the
nucleus.
64 Anticodon Cards: These will be taped to the
walls around the classroom.
Paper: to write down the mRNA strand and the
tRNA molecules and the sentence.
Pen
1. A student picks up a DNA template card, and transcribes it
•
into mRNA.
2. With the mRNA sequence, he goes back to the group’s desk
•
and the ribosomal student writes out the tRNA anticodon
sequence.
DNA template cards.
3. The tRNA student searches out the correct anticodon card
and flip the card over revealing the word and he writes down
1. ATGGCTCCGAGAGGAGGCAGGTAG
the word.
2. ATGCCCCCGAGCCCUTGCTAG
4. After completing the sentence, a student in the group tells his
3. ATGCCCCCGGCACGGGCGTAG
group sentence.
4. ATGTTACCGAGATTCTTGTTTTAG
5. ATGTTACCGTATGTCAAAGGGTAG
The sentences are as follows:
t-RNA Cards with Words.
1. Education is the way to success.
2. Biology is all around you.
AUG = Start , UAG = Stop, GCU = Education,
CCC
3. Biology is so much interesting.
= Biology, CCG = is, AGA = the, AGC = all, GCA = so,
4. DNA is the code of life.
GGA = way, CCU = around, GGC = to, UAU = different,
5. DNA is different in every individual.
UUC = code, GUC = in, UUG = of, AAA = every, UUU =
life, GGG = individual,
UUA = DNA, UGC = you,
Students work in groups - assign one student to be the mRNA,
CGG = much, AGG = success, GCG = interesting
another student to write down the anticodons (ribosome) and the
xxvi
third student to search out the proper words (tRNA).
Procedure:
1. Make up all the DNA Template Cards and the Anticodonword cards.
2. Hang up the Anticodon -word cards, so the anticodons are
showing. (write the anticodon on one side of the card, and
the word on the other).
3. Each group is told that their desk is the nucleus and the DNA
templates cannot leave the area.
4. A student is to pick up a DNA template card, and transcribe
it into mRNA.
5. With the mRNA sequence, he will go back to the group's
desk and the ribosomal student will write out the tRNA
anticodon sequence.
6. The tRNA student will search out the correct anticodon card
and flip the card over revealing the word. He will write down
the word.
7. After completing the sentence, a student in the group will tell
his group sentence. If not correct, have the group go over the
same DNA template. If correct, have the students pick
another card.
Evaluate
Since this is a constructivist lesson, it purposely does not review and
link the new concept to old concepts—it was left to the students to
do the initial linking. Students were allowed to give their responses
based on what they understood and later group interventions were
used to reinforce the concepts. Students were asked to show
translation using the materials provided. Students worked in groups
and demonstrated protein synthesis
xxvii
Review:
1. What is translation?
2. What is meant by charging of t-RNA?
Follow-up Activities:
1. Write a DNA sequence and translate it into a polypeptide sequence.
2. Briefly describe the process of protein synthesis with the help of neat, labeled diagram
xxviii
APPENDIX VII
LIST OF EXPERTS
1. Dr. A. Sukumaran Nair, Former Vice- Chancellor, Mahatma Gandhi
University.
2. Dr. J Exemmal, Former Dean, Faculty of Education, University of Kerala.
3. Dr. B. Suresh, Principal, Institute of Advanced Study in Education,
Trichur.
4. Dr. David Devraj Kumar, Professor of Science Education, Florida Atlantic
University, USA.
5. Dr. Jayasree T. K., Assistant Professor, Government College of Teacher
Education, Thiruvananthapuram.
6. Dr. Oommen P. Mathew, Research Investigator, Population Research
Centre, University of Kerala.
7. Dr. K. Y. Benedict, Associate Professor, Mar Theophilus Training
College, Thiruvananthapuram.
8. Dr. Esther Gladiz, Associate Professor, Mar Theophilus Training College,
Thiruvananthapuram.
9. Dr. Maya S., Assistant Professor, Mar Theophilus Training College,
Thiruvananthapuram
10. Mrs. Lalitha Justin, Biology Teacher, Christ Nagar Higher Secondary
School, Thiruvananthapuram.