Download RP 2L2 Organisms - Parents and Offspring

North Carolina Science Essential Standards
Resource Pack 2.L.2: Organisms – Parents & Offspring
Essential Standard:
2.L.2 Remember that organisms differ from or are similar to their parents based on the
characteristics of the organism.
Clarifying Objectives:
2.L.2.1 Identify ways in which plants and animals closely resemble their parents in observed appearance
and ways they are different.
2.L.2.2 Recognize that there is variation among individuals that are related.
Vertical Strand Maps:
http://scnces.ncdpi.wikispaces.net/Strand+Maps
Online Atlas map http://strandmaps.dls.ucar.edu/?id=SMS-MAP-1381
http://strandmaps.dls.ucar.edu/?id=SMS-MAP-1389
http://strandmaps.dls.ucar.edu/?id=SMS-MAP-1437
North Carolina Unpacking:
http://scnces.ncdpi.wikispaces.net/Race+to+the+Top+Support+Tools
Framework for K-12 Science Education:
LS3: Heredity: Inheritance and Variation of Traits
How are characteristics of one generation passed to the next?
How can individuals of the same species and even siblings have different characteristics?
Heredity explains why offspring resemble, but are not identical to, their parents and is a unifying biological
principle. Heredity refers to specific mechanisms by which characteristics or traits are passed from one
generation to the next via genes. Genes encode the information for making specific proteins, which are
responsible for the specific traits of an individual. Each gene can have several variants, called alleles, which
code for different variants of the trait in question. Genes reside in a cell’s chromosomes, each of which contains
many genes. Every cell of any individual organism contains the identical set of chromosomes. When organisms
reproduce, genetic information is transferred to their offspring. In species that reproduce sexually, each cell
contains two variants of each chromosome, one inherited from each parent. Thus sexual reproduction gives rise
to a new combination of chromosome pairs with variations between parent and offspring. Very rarely,
mutations also cause variations, which may be harmful, neutral, or occasionally advantageous for an individual.
Environmental as well as genetic variation and the relative dominance of each of the genes in a pair play an
important role in how traits develop within an individual. Complex relationships between genes and interactions
of genes with the environment determine how an organism will develop and function.
LS3.A: INHERITANCE OF TRAITS
How are the characteristics of one generation related to the previous generation?
In all organisms, the genetic instructions for forming species’ characteristics are carried in the chromosomes.
Each chromosome consists of a single very long DNA molecule, and each gene on the chromosome is a
particular segment of that DNA. DNA molecules contain four different kinds of building blocks, called
nucleotides, linked together in a sequential chain. The sequence of nucleotides spells out the information in a
gene. Before a cell divides, the DNA sequence of its chromosomes is replicated and each daughter cell receives
a copy. DNA controls the expression of proteins by being transcribed into a “messenger” RNA, which is
translated in turn by the cellular machinery into a protein. In effect, proteins build an organism’s identifiable
traits. When organisms reproduce, genetic information is transferred to their offspring, with half coming from
each parent in sexual reproduction. Inheritance is the key factor causing the similarity among individuals
in a species population.
Grade Band Endpoints for LS3.A
By the end of grade 2. Organisms have characteristics that can be similar or different.
Young animals are very much, but not exactly, like their parents and also resemble other animals of the same
kind. Plants also are very much, but not exactly, like their parents and resemble other plants of the same kind.
By the end of grade 5. Many characteristics of organisms are inherited from their parents. Other characteristics
result from individuals’ interactions with the environment, which can range from diet to learning. Many
characteristics involve both inheritance and environment.
LS3.B: VARIATION OF TRAITS
Why do individuals of the same species vary in how they look, function, and behave?
Variation among individuals of the same species can be explained by both genetic and environmental factors.
Individuals within a species have similar but not identical genes. In sexual reproduction, variations in traits
between parent and offspring arise from the particular set of chromosomes (and their respective multiple genes)
inherited, with each parent contributing half of each chromosome pair. More rarely, such variations result from
mutations, which are changes in the information that genes carry. Although genes control the general traits of
any given organism, other parts of the DNA and external environmental factors can modify an individual’s
specific development, appearance, behavior, and likelihood of producing offspring. The set of variations of
genes present, together with the interactions of genes with their environment, determines the distribution of
variation of traits in a population.
Grade Band Endpoints for LS3.B
By the end of grade 2. Individuals of the same kind of plant or animal are recognizable as similar but can also
vary in many ways.
By the end of grade 5. Offspring acquire a mix of traits from their biological parents. Different organisms vary
in how they look and function because they have different inherited information. In each kind of organism there
is variation in the traits themselves, and different kinds of organisms may have different versions of the trait.
The environment also affects the traits that an organism develops—differences in where they grow or in the
food they consume may cause organisms that are related to end up looking or behaving differently.
Science for All Americans:
HEREDITY
One long-familiar observation is that offspring are very much like their parents but still show some variation:
Offspring differ somewhat from their parents and from one another. Over many generations, these differences
can accumulate, so organisms can be very different in appearance and behavior from their distant ancestors. For
example, people have bred their domestic animals and plants to select desirable characteristics; the results are
modern varieties of dogs, cats, cattle, fowl, fruits, and grains that are perceptibly different from their forebears.
Changes have also been observed—in grains, for example—that are extensive enough to produce new species.
In fact, some branches of descendants of the same parent species are so different from others that they can no
longer breed with one another.
Instructions for development are passed from parents to offspring in thousands of discrete genes, each of which
is now known to be a segment of a molecule of DNA. Offspring of asexual organisms (clones) inherit all of the
parent's genes. In sexual reproduction of plants and animals, a specialized cell from a female fuses with a
specialized cell from a male. Each of these sex cells contains an unpredictable half of the parent's genetic
information. When a particular male cell fuses with a particular female cell during fertilization, they form a cell
with one complete set of paired genetic information, a combination of one half-set from each parent. As the
fertilized cell multiplies to form an embryo, and eventually a seed or mature individual, the combined sets are
replicated in each new cell.
The sorting and combination of genes in sexual reproduction results in a great variety of gene combinations in
the offspring of two parents. There are millions of different possible combinations of genes in the half
apportioned into each separate sex cell, and there are also millions of possible combinations of each of those
particular female and male sex cells. However, new mixes of genes are not the only source of variation in the
characteristics of organisms. Although genetic instructions may be passed down virtually unchanged for many
thousands of generations, occasionally some of the information in a cell's DNA is altered. Deletions, insertions,
or substitutions of DNA segments may occur spontaneously through random errors in copying, or may be
induced by chemicals or radiation. If a mutated gene is in an organism's sex cell, copies of it may be passed
down to offspring, becoming part of all their cells and perhaps giving the offspring new or modified
characteristics. Some of these changed characteristics may turn out to increase the ability of the organisms that
have it to thrive and reproduce, some may reduce that ability, and some may have no appreciable effect.
EVOLUTION OF LIFE
The earth's present-day life forms appear to have evolved from common ancestors reaching back to the
simplest one-cell organisms almost four billion years ago. Modern ideas of evolution provide a scientific
explanation for three main sets of observable facts about life on earth: the enormous number of different life
forms we see about us, the systematic similarities in anatomy and molecular chemistry we see within that
diversity, and the sequence of changes in fossils found in successive layers of rock that have been formed over
more than a billion years.
Since the beginning of the fossil record, many new life forms have appeared, and most old forms have
disappeared. The many traceable sequences of changing anatomical forms, inferred from ages of rock layers,
convince scientists that the accumulation of differences from one generation to the next has led eventually to
species as different from one another as bacteria are from elephants. The molecular evidence substantiates the
anatomical evidence from fossils and provides additional detail about the sequence in which various lines of
descent branched off from one another.
Although details of the history of life on earth are still being pieced together from the combined geological,
anatomical, and molecular evidence, the main features of that history are generally agreed upon. At the very
beginning, simple molecules may have formed complex molecules that eventually formed into cells capable of
self-replication. Life on earth has existed for three billion years. Prior to that, simple molecules may have
formed complex organic molecules that eventually formed into cells capable of self-replication. During the first
two billion years of life, only microorganisms existed—some of them apparently quite similar to bacteria and
algae that exist today. With the development of cells with nuclei about a billion years ago, there was a great
increase in the rate of evolution of increasingly complex, multicelled organisms. The rate of evolution of new
species has been uneven since then, perhaps reflecting the varying rates of change in the physical environment.
A central concept of the theory of evolution is natural selection, which arises from three well-established
observations: (1) There is some variation in heritable characteristics within every species of organism, (2) some
of these characteristics will give individuals an advantage over others in surviving to maturity and reproducing,
and (3) those individuals will be likely to have more offspring, which will themselves be more likely than others
to survive and reproduce. The likely result is that over successive generations, the proportion of individuals that
have inherited advantage-giving characteristics will tend to increase.
Selectable characteristics can include details of biochemistry, such as the molecular structure of hormones or
digestive enzymes, and anatomical features that are ultimately produced in the development of the organism,
such as bone size or fur length. They can also include more subtle features determined by anatomy, such as
acuity of vision or pumping efficiency of the heart. By biochemical or anatomical means, selectable
characteristics may also influence behavior, such as weaving a certain shape of web, preferring certain
characteristics in a mate, or being disposed to care for offspring.
New heritable characteristics can result from new combinations of parents' genes or from mutations of them.
Except for mutation of the DNA in an organism's sex cells, the characteristics that result from occurrences
during the organism's lifetime cannot be biologically passed on to the next generation. Thus, for example,
changes in an individual caused by use or disuse of a structure or function, or by changes in its environment,
cannot be promulgated by natural selection.
By its very nature, natural selection is likely to lead to organisms with characteristics that are well adapted to
survival in particular environments. Yet chance alone, especially in small populations, can result in the spread
of inherited characteristics that have no inherent survival or reproductive advantage or disadvantage. Moreover,
when an environment changes (in this sense, other organisms are also part of the environment), the advantage or
disadvantage of characteristics can change. So natural selection does not necessarily result in long-term
progress in a set direction. Evolution builds on what already exists, so the more variety that already exists, the
more there can be.
The continuing operation of natural selection on new characteristics and in changing environments, over and
over again for millions of years, has produced a succession of diverse new species. Evolution is not a ladder in
which the lower forms are all replaced by superior forms, with humans finally emerging at the top as the most
advanced species. Rather, it is like a bush: Many branches emerged long ago; some of those branches have died
out; some have survived with apparently little or no change over time; and some have repeatedly branched,
sometimes giving rise to more complex organisms.
The modern concept of evolution provides a unifying principle for understanding the history of life on earth,
relationships among all living things, and the dependence of life on the physical environment. While it is still
far from clear how evolution works in every detail, the concept is so well established that it provides a
framework for organizing most of biological knowledge into a coherent picture.
Benchmarks for Science Literacy:
Building an observational base for heredity ought to be the first undertaking. Explanations can come later. The
organisms children recognize are themselves, their classmates, and their pets. And that is the place to start
studying heredity. However, it is important to be cautious about having children compare their own physical
appearance to that of their siblings, parents, and grandparents. At the very least, the matter has to be handled
with great delicacy so no one is embarrassed. Direct observations of generational similarities and differences of
at least some plants and animals are essential.
Learning the genetic explanation for how traits are passed on from one generation to the next can begin in the
middle years and carry into high school. The part played by DNA in the story should wait until students
understand molecules. The interaction between heredity and environment in determining plant and animal
behavior will be of interest to students. Examining specific cases can help them grasp the complex interactions
of genetics and environment.
K-2
Teachers should lead students to make observations about how the offspring of familiar animals compare to one
another and to their parents. Children know that animals reproduce their own kind—rabbits have rabbits (but
you can usually tell one baby rabbit from another), cats have kittens that have different markings (but cats never
have puppies), and so forth. This idea should be strengthened by a large number of examples, both plant and
animal, that the children can draw on.
By the end of the 2nd grade, students should know that
 There is variation among individuals of one kind within a population. 5B/P1
 Offspring are very much, but not exactly, like their parents and like one another. 5B/P2
3-5
Students should move from describing individuals directly (she has blue eyes) to naming traits and classifying
individuals with respect to those traits (eye color: blue). Students can be encouraged to keep lists of things that
animals and plants get from their parents, things that they don't get, and things that the students are not sure
about either way. This is also the time to start building the notion of a population whose members are alike in
many ways but show some variation.
By the end of the 5th grade, students should know that
 Some likenesses between children and parents are inherited. Other likenesses are learned. 5B/E1*
 For offspring to resemble their parents, there must be a reliable way to transfer information from one
generation to the next. 5B/E2
Big Ideas:
Essential Questions:


In what ways do offspring resemble their parents? …in what ways do they differ?
Do offspring always resemble one another?
Enduring Understandings:
Students will understand that
 Offspring are similar to, and different than their parents and siblings.
 Physical traits are inherited from parents.
 Characteristics are passed from parent to offspring.
 Each parent contributes to the offspring.
 Siblings can resemble one another, or they can be very different.
Identify Misconceptions:
Formative Assessment Probe Guide
http://scnces.ncdpi.wikispaces.net/Formative+Assessment+Probe+Alignment
Common Misconceptions
http://wiki.nb27.org/science/1stOrganisms/first/organisms/docs/1stPlantsAnimalsMiscon.pdf
http://www.neisd.net/curriculum/SchImprov/sci/program/misconceptions_inter.htm#lifecycle
Annotated TEACHING Resources:
NCES 2nd Grade Parents and Offspring
http://www.livebinders.com/play/play?id=1641233
NCES 2nd Grade Science Livebinder
http://www.livebinders.com/play/play?id=478563
Organisms and offspring unit
This unit was authored by a team of educators. The template provided one example of unit design that
enabled teacher-authors to organize possible learning experiences, resources, differentiation, and
assessments. The unit is intended to support teachers, schools, and districts as they make their own local
decisions around the best instructional plans and practices for all students.
https://www.cde.state.co.us/standardsandinstruction/sc1-organismsandoffspring-pdf
Cscope Investigating Animals unit
Students will observe and explore ways that young animals often resemble their parents through
coloration, body structure, and behavior.
http://www.bigspringisd.net/Uploads/177/misc/f266812.pdf
STEM Module – Parents and Offspring
This is a module focused on the inheritance of traits.
http://www.harmonydc.org/Curriculum/pdf/1sample.pdf
Parents and offspring unit
How are plants and animals like their parents? Powerpoint in pdf.
http://web.compton.k12.ca.us/pages/departments/curriculum/pdf/2ndgradesciunitb.pdf
Are You my Parents? Unit
These lesson activities allow students to explore the life cycles of various animals and how the offspring
resemble their parents and each other. They include the investigation of traits, both physical and
behavioral, that affect an organism’s ability to survive and reproduce.
http://www.ccsoh.us/Downloads/3LS123C%20AreYouMyParents.pdf
Video Resources:
Baby animal songs
https://www.youtube.com/watch?v=cJg4YFtvOp8
https://www.youtube.com/watch?v=ZPzRyto8ryU
Text Resources:
http://www.alphabet-soup.net/farm/animalbookmain.html
https://www.lernerbooks.com/SiteCollectionDocuments/TeachingGuides/9780822556589.pdf
Word Walls:
https://www.google.com/search?q=parents+and+offspring+word+walls&biw=1390&bih=1105&source
=lnms&tbm=isch&sa=X&ved=0ahUKEwiT9Jn9t7nOAhVFyyYKHTltCQMQ_AUIBigB&dpr=0.8#tbm=isch&q
=animal+parents+and+babies+wordwalls
Pictures:
https://www.google.com/search?q=parents+and+offspring+word+walls&biw=1390&bih=1105&source
=lnms&tbm=isch&sa=X&ved=0ahUKEwiT9Jn9t7nOAhVFyyYKHTltCQMQ_AUIBigB&dpr=0.8#tbm=isch&q
=animal+parents+and+babies
http://www.boredpanda.com/cute-animal-parenting/
Writing Prompts:
1. Imagine that you have an identical twin. What would be some advantages and disadvantages of having
an identical twin?
2. Look at a series of family pictures with parents and children. Describe how the children are similar to
their parents and similar to one another.
3. Create a picture book that includes the names of animal parents and their offspring.
4. Investigate a species of bird. Write a summary of how this bird and their offspring are similar and
different as the baby bird grows and develops.
5. Write an essay about two very different types of dogs. Explain how they can both be dogs, yet still be
very, very different.