Download Sample 5.3.B.2 Complete

5.3.12.D. 3 2011
5.3 Life Science: Life science principles are powerful conceptual tools for making sense of the complexity, diversity, and
interconnectedness of life on Earth. Order in natural systems arises in accordance with rules that govern the physical world, and
the order of natural systems can be modeled and predicted through the use of mathematics.
D. Heredity and Reproduction: Organisms reproduce, develop, and have predictable life cycles. Organisms contain genetic
information that influences their traits, and they pass this on to their offspring during reproduction
Essential Questions
Enduring Understandings
Labs, Investigation, and Student Experiences
How is genetic information
passed through
generations?
There are predictable patterns of
inheritance, and the variation that
exists within a species is related to
its mode of reproduction (sexual
or asexual).
5.3.12.D. 3
Content Statements
Sorting and recombination
of genes in sexual
reproduction result in a
great variety of possible
gene combinations in the
offspring of any two
parents.
Cumulative Progress
Indicators
Demonstrate through modeling
how the sorting and
recombination of genes during
sexual reproduction has an effect
on variation in offspring (meiosis,
fertilization). (5.3.12.D.3)
Marshmallow Meiosis
Purpose: To investigate how variation arises as a result of
meiosis and fertilization in sexually reproducing organisms.
Introduction: Meiosis is a special type of cell division that takes
place in certain cells of sexually reproducing organisms. It
results in the production of four daughter cells called gametes
that have half the number of chromosomes than that of the
original cell. That is why meiosis is sometimes called
REDUCTION DIVISION. Furthermore, the four gametes
arising from a single cell are different from each other in their
genetic makeup.
chromosomes (2N=6,) made from marshmallow and toothpicks.
It is suggested to write letters A, B, D, E, F, G on the
marshmallows in female parent cell to depict genes present in
the genotype of one chromosome. Another parent cell would
contain the same number of chromosomes (2N=6) in male
parent cell with recessive versions of the same genes: a, b, d, e,
f, g. Other letters of alphabet should be written on
marshmallows representing genes on other chromosomes. Jelly
beans connected by toothpicks represent the centromeres of the
chromosomes. At the moment, each chromosome is made up of
one chromatid, here is one line of marshmallows connected by
the toothpicks. Teacher explains that during S phase of the
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5.3.12.D. 3 2011
Desired Results
Students will be able to…
1. Explain the cell cycle, how it contributes to reproduction and
maintenance of the cell and/or organism, and explain where
mitosis fits into the cell cycle.
2. Understand the factors that cause cells to reproduce.
3. Be able to describe each phase of mitosis and make a simple
labeled drawing of mitosis.
Indicate that resulting cells contain an identical copy of genetic
information from the parent cell.
4. Explain how the apportioning of cytoplasm to the daughter
cells follows mitosis, a nuclear eve nt.
5. Compare and contrast asexual and sexual types of
reproduction that occur on the cellular and multicellular
organism levels. Understand how asexual reproduction differs
from sexual reproduction. Know the advantages and
disadvantages of each.
6. Explain through the use of models or diagrams, why sexuallyproduced offspring are not identical to their parents.
7. Describe the events that occur in each meiotic phase.
8. Compare mitosis and meiosis; cite similarities and differences
9. Recognize that during the formation of gametes, or sex cells
(meiosis), the number of chromosomes is reduced by one half,
so that when fertilization occurs the diploid number is
restored.
10. Recognize random mutation (changes in DNA) and events
that occur during gamete formation and fertilization (i.e.,
crossing over, independent assortment and recombination of
chromosomes) as the sources of heritable variations that give
individuals within a speciessurvival and reproductive advantage
or disadvantage over others in the species.
11. Explain why sex-linked traits are expressed more frequently
Interphase, chromatids duplicate, now each chromosome
consists of two chromatids, or two lines of marshmallows
connected by toothpicks and both lines connected by a toothpick
via a jellybean, as a centromere.
Students will resemble the makeup of the parent cell and
proceed with phases of the meiosis now. Four groups of 3-5
students will work on imitating a crossing over in the Prophase
I. Students will pair up homologous chromosomes by aligning
marshmallows into pairs (homologous chromosomes) and join
the jelly beans of each line of marshmallows, thus forming
tetrads. Now, students are ready to proceed with imitation of the
crossing-over by randomly exchanging the marshmallows
blocks with written letters on them between lines of
marshmallows that represent non-sister chromatids of
homologous chromosomes; thus only letters of the same type
can be exchanged: A with a; b with B, etc. Teacher should
constantly remind students that this process is random – some
letters are exchanged and others are not. The longer the line of
marshmallow (the longer the chromatid), the higher the rate of
the crossing-over! The Y chromosome is extremely small, and
does not undergo crossing-over with the X chromosome.
At this moment, teacher asks students to compare the genotype
of the cell in the Prophase I with the original parent cell (a
teacher’s model). Students should arrive to a conclusion that the
crossing-over brings the gene shuffling and as a result the cell in
Prophase has a very different genotype from the original parent
cell.
Next, students imitate the metaphase of the Meiosis I by
aligning the pairs of homologous chromosomes on the equator
of an imaginary cell. Alignment of pairs of homologous
chromosomes on the metaphase plate (an equator) is also
random. Teacher stresses out that in Anaphase I there is a
random separation of chromosomes from each pair. This random
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in males.
12. Compare and contrast the processes of growth (cell division)
and development (differentiation).
13. Recognize that any environmental factor that influences gene
expression or alteration in hormonal balance may have an impact
on development.
14. List some of the problems in cell division when control is
lost.
15. Recognize that cancer is a result of mutations that affect the
ability of cells to regulate the cell cycle.
16. Describe early embryonic development and distinguish each:
oogenesis, fertilization, cleavage, gastrulation and organ
formation.
17. Describe the structure and function of the human male and
female reproductive systems.
18. Model a random process (e.g., coin toss) that illustrates
which alleles can be passed from parent to offspring.
19. Describe the relationship between DNA, genes,
chromosomes, proteins and the genome.
20. Explain that a gene is a section of DNA that directs the
synthesis of a specific protein associated with a specific trait in
an organism.
21. Use Punnett squares, including dihybrid crosses, and
pedigree charts to determine probabilities and patterns of
inheritance (i.e. dominant/recessive, co-dominance,
autosomal/sex-linkage, multiple-allele inheritance).
22. Analyze a karyotype to determine chromosome numbers and
pairs. Compare and contrast normal and abnormal karyotypes.
23. Explain how sex chromosomes inherited from each parent
determines the gender of the offspring.
separation of chromosomes from the homologous pair represents
the independent assortment. At the end of the Anaphase I, one
chromosome form each homologous pair is moved to the
opposite poles, thus at the end of Telophase I and followed
cytokinesis, two daughter cells are formed different form each
other and from the parent cell. These cells are haploid (N=3),
and they have different genetic makeup – marshmallow lines
have a very random letters of upper and low cases: AbDEFg,
and aBdefG.
Students proceed with the rest of Meiosis II and should end up
with four haploid cells, which now would participate in
fertilization.
Students asked to record the sequence of the letters, representing
the genes on each line on a separate index card. Each group will
be given 4 ziplock bags of small size for cells that came from
the male parent cell, and 4 ziplock bags of really large size for
the cells coming from the female parent cell. One card will list
letters (genes) that are present on one chromosome. Each
ziplock bag would have 3 index cards: 2 cards list the sequence
of letters (genes) on the two autosomes and one card will have
either X letter or Y letter.
Students with the small ziplock bags, representing sperm cells
are on the one side of the room, and students with the large
ziplock bags, representing egg cells. Teacher stress the fact that
small bags (sperm cells have either X chromosome or Y
chromosome) and large ziplock bags contain only X
chromosomes. Now, teacher explains that fertilization is a
random process, and sperm cell with most energy and speed will
actually participate in the process. So, students who hold the
small bag, are asked to do ten set ups, ten jumps, and run to any
student who holds the large bag in order to put cards from the
small bag into the large bag, thus representing the randomness
of the process. Now students analyze the genotype of the
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fertilized egg. They should see that its genetic makeup is very
different from both original parent cells. Teacher repeats that it
is due to the random process of the crossing-over and
independent assortment, or separation of chromosomes in the
anaphase I.
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5.3.12.D. 3 2011
PERFORMANCE ASSESSMENT
“Effect of Coffee on Health”
OVERVIEW
Coffee is a brewed beverage prepared from roasted seeds, known as coffee beans, of the coffee plant.
Due to its caffeine content, coffee can have a stimulating effect in humans. Today, coffee is one of the most popular beverages
worldwide.
Some scientists conducted an experiment in which they evaluated various measurements of human health in people who drank at least
one cup of coffee a day.
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5.3.12.D. 3 2011
They found no significant differences in the health indicators between the subjects who drank only one cup of coffee a day and those
who drank as many as 20 cups a day. They concluded that coffee has no adverse effects on human health. Write your answers to the
following in the spaces below.
YOUR TASK
1. What were the independent and dependent variables in this experiment?
2. Was this a controlled experiment? If so, what were the control and experimental groups?
3. Do you agree with the conclusion the scientists drew from their results? Why or why not?
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