LabLearner—The Science of Learning
LabLearner—The Science of Learning

Teacher Portal

Adaptation

Investigation 1 – PreLab

 

 

 

 

 

 

 

Back to Investigation 1

ZERO-IN

Italicized font represents information to be shared orally or physically completed with the students at this time.

The non-italicized font represents additional information included to support the teacher’s understanding of the content being introduced within the CELL.

ASK WHY

Remind students that the planet we live on is constantly changing. To survive and reproduce, all living organisms must adjust to these changes. If organisms are not able to adapt to changing environmental factors — including competition for resources, predation, infectious diseases, and climate – they may not survive.

BRANCH OUT

Remind students that evolutionary biologists seek to understand the origin of organisms, their genetic variations over time and how they are currently adapting. They might try to discover the earliest ancestors of modern humans. Or he or she may analyze a flu virus to understand how it develops resistance to vaccines.

GET FOCUSED

Inform students that the Investigation is designed to help them to answer the following Focus Question:

  • Why do individuals of a species have different traits? The genotype of an individual determines the phenotype of the individual. Genetic variation ensures that there are many possible genotypes and phenotypes that an organism can possess. This genetic variation is a result of mutations, recombination of genes, and the random mating of individuals.
  • What is the relationship between the survival of the individuals of a species and genetic variations? Genetic variation is the reason why there are many unique individuals of a species in a population. Genetic variation allows a population of species to survive different environmental pressures.

Note: This question is located in students’ SDRs at the beginning and end of the Investigation.

Note: This is a succinct response to the Focus Question and is placed here for your reference at this time. A fully developed response to the Focus Question can be found on the PostLab page.

GO DEEPER

As a class, read the Background(s) in the Investigation. Have students read the information aloud or silently to themselves. When students have finished, discuss the following concepts as a class:

  • Many species have developed traits that allow them to survive in a particular environment. These traits are often called adaptations.
  • Not all individual organisms of a species that live in an environment have exactly the same trait or adaptation. The difference of traits is described as variation.
  • Genes are the building blocks for the specific traits that allow organisms to adapt to their environment.
  • A trait is any genetically inherited feature of an organism, such as eye color.
  • These traits are coded for by genes.
  • In all organisms, there is more than one possible form for each gene. Each possible form is called an allele.
  • The differences in the forms of a gene are described as genetic variation.
  • Genes are often made up of two alleles that have a special relationship to each other.  
  • The DNA of most cells of an organism has two copies of a gene, or two alleles. One allele is from the father and one is from the mother.
  •  A recessive allele is one that is displayed only when there is no dominant allele. 
  • The combination of alleles in an organism is called its genotype.
  • The form or variation of the trait that results from the combination of alleles is called its phenotype.
  • Differences in the genotype are described as genetic variation. These can lead to differences in the phenotype which are described as variations of a trait that you can observe.
  • When the two alleles are the same (either both are dominant or both are recessive) the genotype is said to be homozygous.
  • When the two alleles are different (one is dominant and one is recessive), the genotype is said to be heterozygous.
  • When organisms reproduce, one allele comes from the mother and one comes from the father. This process occurs at random so that either allele can be passed on to the offspring. There are then many possible combinations of alleles.

Note: These concepts are integrated into the Background(s) and are used to deepen students’ comprehension of the big ideas.

 

LEARN THE LabLearner LINGO

The following list includes Key Terms that are introduced in the Investigation Background(s). They should be used, as appropriate, by teachers and students during everyday classroom discourse.

  • species
  • trait
  • genetic variation
  • adaptation
  • environment
  • allele
  • dominant
  • recessive
  • genotype
  • phenotype

Note: Definitions to these terms can be found on the Introduction page to the CELL.

Note: Additional words may be bolded within the Background(s). These words are not Key Terms and are strictly emphasized for exposure at this time.

SET FOR SUCCESS

  • Direct students to complete the Recall section in their SDRs. Student answers will vary.
  • Are all members of a species exactly alike?
  • How do the traits or adaptations that animals and plants have help them survive in their environments?
  • Does variation in traits permit survival of individuals in a species?
  • Play the video below. Stop to ask students questions or answer students’ questions when necessary. Remind students to follow along with their SDRs and make any notes that they think might be helpful.
  • After the video, direct students to divide into their lab groups to discuss their strategy for the lab. For example, they may assign certain group members to perform specific functions during the lab.

Note: The purpose of the video is to allow students to anticipate the laboratory experience they will soon encounter. Students should leave this PreLab session with a firm idea of what to expect and how to perform in the lab.

Note: Homework is posted below the video.

HOMEWORK

Tell students that they should review the Investigation in preparation for the Lab.