HEREDITY: INHERITANCE and TRENDS
Unit Cover Page
Topic Areas: DNA, Cell Reproduction and Specialization, Genetics
Summary of Unit: The purpose of this unit is to assist students in formulating answers to the questions: “How
are characteristics of one generation passed to the next? How can individuals of the same species and even
siblings have different characteristics?”
Additionally, students need to demonstrate understanding of:
* the relationships of the role of DNA and chromosomes in coding the instructions for characteristic
traits passed from parent to offspring;
* explain how DNA structure determines the proteins which carry out life functions through system of
specialized cells;
* use a model to illustrate the role of cellular division, and differentiation in producing and maintaining
complex organisms;
* make a defend a claim based on evidence that inheritable genetic variations may result from defined
parameters,
* apply concepts of statistics and probability to explain the variation and distribution of expressed traits
in a population.
Standards:
DNA: NGSS HS-LS 1-1, HS-LS 1-4, HS-LS 3-1
Reproduction: NGSS HS-LS 1-2, HS-LS 1-4, HS-LS 3-2
Genetics: NGSS HS-LS 3-1, HS-LS 3-2, HS-LS 3-3
Literacy:
RST.11-12.1 Cite specific textual evidence to support analysis of science and
technical texts
RST.11-12.9 synthesize information from a range of sources into a coherent
understanding of a process, phenomenon, or concept, resolving conflicting
information when possible.
Resources: CellsAlive.com, DNAi.org, YouTube Videos (Bozeman, Crash Course), GeneticsAlive.com
Key Words:
Mitosis
Cytokinesis
Chromatid
Centromere
Centriole
Spindle
Cell Cycle
Cloning
Selective
Breeding
Nondisjunction
Cyclins
Stem Cells
Trait
Allele
Hybrid
Gene
Gamete
Sex-linked
Hybridization
Polyploidy
Segregation
Probability
Punnet Square
Homozygous
Heterozygous
Genotype
Phenotype
Pedigree
Karyotype
Mutations
Homologous
Diploid
Haploid
Meiosis
Tetrad
Crossing Over
Incomplete
Dominance
Multiple Alleles
Autosome
Translation
Transcription
Co-Dominance
Essential Questions: students will keep considering…
How can I influence my chances of getting cancer?
Why do some family members exhibit traits that are different from the rest of the family?
How do genetic abnormalities affect an individual?
How are traits inherited? Are they all inherited the same way?
What traits did I inherit from my parents?
Polygenic
Dihybrid
Nucleotide
Transformation
Chromatin
Chromosome
Codon
Anticodon
Knowledge: students will know….
 All cells contain genetic information in the form of DNA molecules. Genes are regions in the DNA that
contain instructions that code for the formation of proteins. (LS1.A)

Each chromosome consists of a single very long DNA molecule, and each gene on the chromosome is a
particular segment of the DNA. The instructions for forming species characteristics are carried in DNA.
All cells in an organism have the same genetic content, but the genes expressed by the cell may be
regulated in different ways. Not all DNA codes for a protein; some segments of DNA are involved in
regulatory or structural functions and some have no, as yet known, function. (LS3.A)

In sexual reproduction, chromosomes can sometimes swap sections in the process of meiosis, thereby
creating new genetic combinations and thus more genetic variation. Although DNA replication is
tightly regulated and remarkably accurate, errors do occur and result in mutations, which are also a
source of genetic variation. Environmental factors can also cause mutations in genes, and viable
mutations are inherited. (LS3.B)

Environmental factors also affect expression of traits, and hence affect the probability of occurrences of
traits in a population. Thus the variation and distribution of traits observed depends on both genetic and
environmental factors. (LS3.B)

In multicellular organisms individual cells grow and then divide via a process called mitosis, thereby
allowing the organism to grow. The organism begins as a single cell (fertilized egg) that divides
successively to produce many cells, with each parent cell passing identical genetic material (two variants
of each chromosome pair) to both daughter cells. Cellular division and differentiation produce a
maintain a complex organism, composed of systems of tissues and organs that work together to meet the
needs of the whole organism (LS1.B)
Misconceptions:
 All cells produce the same way.
 All offspring should resemble their parents.
 All siblings should have similar characteristics.
 Clones are exact copies of the original organism.
 The number of chromosomes does not indicate the complexity of an organism.
 Any two species can interbreed.
 Stem cells are only available through embryonic tissues.