Heredity and Genetics Vocabulary List
Gregor Mendel studied inheritance of traits in pea plants. . it turned out, the 3: 1 ratio was a crucial clue that let Mendel crack the puzzle of inheritance. 1. traits - characteristics. 2. genetics - the study of heredity. 3. Gregor Mendel - father of genetics. 4. allele - different forms of a single gene. 5. dominant allele - a . In thinking about inherited traits, geneticists use two important words: genotype and phenotype. Genotype refers to the genes an organism inherits from its.
Heredity and Genetics Vocabulary List
Hand out the following to each pair of students: Explain that a similar base pairing process takes place in transcription but instead of the A—T pairing found in DNA, in transcription, the base adenine pairs with uracil found in RNA. Instruct students that you will guide them through the transcription process as follows: Students will work with partners to model the actual sequence of steps used by the cell to carry out transcription.
Tell students that even though they will be able to think of a faster way to make the mRNA, they should follow the sequence of steps described in their hand-outs in order to learn how the cell actually makes mRNA. Have each pair of students complete the Transcription Modeling Procedure from their handouts on page 3. Observe pairs to make sure students are following the procedures correctly and using the materials appropriately.
Once they have completed the Transcription Modeling Procedures, have students review their answers in the questions document.
The law of segregation
Reviewing student responses for thoroughness and accuracy can show which students have a strong understanding of the concept and which students may need additional support. Circulate through the class assisting groups in need of assistance. Instruct students to summarize what they have learned by explaining how a gene directs the synthesis of an mRNA molecule.
Tell students to include in their explanation the words and phrases: Days 3—4 Begin by allowing students to share responses to the exit slip question given at the end of the last class. Together, students will share best responses and select the most appropriate responses to the question.
Inform students that next they will model the process of translation. Have students review the content previously covered on translation.
Begin to clarify concepts on translation. Ask student volunteers to review content and begin class discussion for clarification of concepts.
- The law of segregation
- Patterns of inheritance
When you have determined that students are ready to move forward, they can begin the Translation Modeling Procedure on pages 5—7 in their handouts. Have students return to groups from Day 1. Instruct students to read pages 3—4 of the student handout, and then follow the Translation Modeling Procedure. Actively monitor student groups as they carry out the procedure, answering questions as needed.
Gather the class together and direct students to work through all of the remaining questions in their questions document. Instruct students to summarize what they have learned by explaining how a gene directs the synthesis of a protein. Day 5 Place students in small groups and give each group a poster or chart paper and a marker.
Have each group of students brainstorm vocabulary and concepts from Lessons 1 and 2 and jot them down on the poster.
In diploid organisms each body cell or 'somatic cell' contains two copies of the genome. So each somatic cell contains two copies of each chromosome, and two copies of each gene.
The exceptions to this rule are the sex chromosomes that determine sex in a given species. For example, in the XY system that is found in most mammals - including human beings - males have one X chromosome and one Y chromosome XY and females have two X chromosomes XX.
The paired chromosomes that are not involved in sex determination are called autosomes, to distinguish them from the sex chromosomes. Human beings have 46 chromosomes: The different forms of a gene that are found at a specific point or locus along a given chromosome are known as alleles. Diploid organisms have two alleles for each autosomal gene - one inherited from the mother, one inherited from the father.
Mendelian inheritance patterns Within a population, there may be a number of alleles for a given gene. Individuals that have two copies of the same allele are referred to as homozygous for that allele; individuals that have copies of different alleles are known as heterozygous for that allele.
The inheritance patterns observed will depend on whether the allele is found on an autosomal chromosome or a sex chromosome, and on whether the allele is dominant or recessive.
The Roles of DNA, Genes, Alleles, and Chromosomes in Inheritance - SAS
Autosomal dominant If the phenotype associated with a given version of a gene is observed when an individual has only one copy, the allele is said to be autosomal dominant. The phenotype will be observed whether the individual has one copy of the allele is heterozygous or has two copies of the allele is homozygous.
Autosomal recessive If the phenotype associated with a given version of a gene is observed only when an individual has two copies, the allele is said to be autosomal recessive.
The phenotype will be observed only when the individual is homozygous for the allele concerned. An individual with only one copy of the allele will not show the phenotype, but will be able to pass the allele on to subsequent generations.
As a result, an individual heterozygous for an autosomal recessive allele is known as a carrier. Sex-linked or X-linked inheritance In many organisms, the determination of sex involves a pair of chromosomes that differ in length and genetic content - for example, the XY system used in human beings and other mammals.
The X chromosome carries hundreds of genes, and many of these are not connected with the determination of sex. The smaller Y chromosome contains a number of genes responsible for the initiation and maintenance of maleness, but it lacks copies of most of the genes that are found on the X chromosome. As a result, the genes located on the X chromosome display a characteristic pattern of inheritance referred to as sex-linkage or X-linkage.