Essential Idea: Chromosomes carry genes in a linear sequence that is shared by members of a species.
- Outline answer to each objective statement for topic 3.2 (coming soon)
- Quizlet study set for this topic
At SHS, Topic 3.2 is taught in the following class unit(s):
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3.2.U1 Prokaryotes have one chromosome consisting of a circular DNA molecule.
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3.2.U2 Some prokaryotes also have plasmids but eukaryotes do not.
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3.2.U3 Eukaryote chromosomes are linear DNA molecules associated with histone proteins.
- Describe the structure of eukaryotic DNA and associated histone proteins during interphase (chromatin).
- Explain why chromatin DNA in interphase is said to look like “beads on a string.”
3.2.U4 In a eukaryote species there are different chromosomes that carry different genes.
- List three ways in which the types of chromosomes within a single cell are different.
- State the number of nuclear chromosome types in a human cell.
3.2.U5 Homologous chromosomes carry the same sequence of genes but not necessarily the same alleles of those genes.
- Define homologous chromosome.
- State a similarity and a difference found between pairs of homologous chromosomes.
3.2.U6 Diploid nuclei have pairs of homologous chromosomes.
- Define diploid.
- State the human cell diploid number.
- Outline the formation of a diploid cell from two haploid gametes.
- State an advantage of being diploid.
3.2.U7 Haploid nuclei have one chromosomes of each pair.
- Define haploid.
- State the human cell haploid number.
- List example haploid cells.
3.2.U8 The number of chromosomes is a characteristic feature of member of a species.
- State that chromosome number and type is a distinguishing characteristic of a species.
- List mechanisms by which a species chromosome number can change.
3.2.U9 A karyogram shows the chromosomes of an organism in homologous pairs of decreasing length.
- Describe the process of creating a karyogram.
- List the characteristics by which chromosomes are arranged on the karyogram.
3.2.U10 Sex is determined by sex chromosomes and autosomes are chromosomes that do not determine sex.
- Outline the structure and function of the two human sex chromosomes.
- Outline sex determination by sex chromosomes.
3.2.A1 Cairns’ technique for measuring the length of DNA by autoradiography.
- Describe Cairn’s technique for producing images of DNA molecules from E. coli.
- Outline conclusions drawn from the images produced using Cairn’s autoradiography technique.
3.2.A2 Comparison of genome size in T2 phage, Escherichia coli, Drosophila melanogaster, Homo sapiens, Paris japonica.
- Describe the relationship between the genome size of a species and the species complexity in structure, physiology and behavior.
3.2.A3 Comparison of diploid chromosome numbers of Homo sapiens, Pan troglodytes, Canis familiaris, Oryza sativa, Parascarsis equorum.
- State the minimum chromosome number in eukaryotes.
- Explain why the typical number of chromosomes in a species is always an even number.
- Explain why the chromosome number of a species does not indicate the number of genes in the species.
- Explain the relationship between the number of human and chimpanzee chromosomes.
3.2.A4 Use karyograms to deduce sex and diagnose Down Syndrome in humans.
- Distinguish between a karyogram and a karyotype.
- Deduce the sex of an individual given a karyogram.
- Describe the use of a karyogram to diagnose Down syndrome.
3.2.S1 Use of databases to identify the focus of a human gene and its polypeptide product.
- Search NCBI or OMIM for a given gene.
- Determine the gene locus, abbreviated gene name, and description of the gene.
3.2.NOS Developments in research follow improvements in techniques- autoradiography was used to establish the length of DNA molecules in chromosomes.
- Outline the advancement in knowledge gained from the development of autoradiography techniques.
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If you've found the materials helpful, please consider making a contribution of any amount
to this Earthwatch Expedition Fund.
Did I forget something? Know of a mistake? Have a suggestion? Let me know by emailing me here.
Before using any of the files available on this site,
please familiarize yourself with the Creative Commons Attribution License.
It prohibits the use of any material on this site for commercial purposes of any kind.
