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4.1 Chromosomes, Genes, Alleles, and Mutations
Terms in this set (4)
4.1.1. State that eukaryote chromosomes are made of DNA and protein.
All the chromosomes find in the nucleus of eukaryotic cells are made of DNA.
To fit all the DNA inside the nucleus, you need to fold it (coiled) around proteins called histones.
4.1.2. Define gene, allele, and genome.
Gene is a unit of inheritance;
Gene is composed of DNA.
Gene controls a specific characteristic or codes for a protein.
Allele is a form or an alternative of a gene;
Alleles of a gene occupy the same position on chromosome;
Alleles differ (from each other) by a small number of base(s).
Genome: The whole genetic information of an organism.
4.1.3. Define gene mutation
Gene mutation is a change in the base sequence of an allele.
The changed base sequence may produce a different amino acid sequence in the protein translated.
The changed base sequence may not change the protein because of the degenerate nature of the genetic code.
The expression of the mutated gene may or may not be beneficial to the organism.
4.1.4. Explain the consequences of a base substitution in relation to the process of transcription and translation, using the example of sickle cell anemia.
Mutation is a change in DNA sequence;
This will change the mRNA during transcription;
This will change the translation of the mRNA into a protein;
The normal codon GAG on the mRNA with the base substitution will now be GTG;
It means that the amino acid sequence won't be the same;
Instead of getting a glutamic acid you now get the amino acid called valine;
This will change the shape of hemoglobin (sickle) in the red blood cells (RBC);
RBC cannot carry oxygen as well as normal RBC;
It causes health problems: i.e. anemia, tiredness.
THIS SET IS OFTEN IN FOLDERS WITH...
3.5 Transcription and Translation
3.4 DNA Replication
3.3 DNA Structure
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