MCAS BIOLOGY REVIEWGENETICS

Ms. MezzettiLynn English High School

3.1: DNA Structure & FunctionDescribe the basic structure (double helix, sugar/phosphate backbone, linked by complementary nucleotide pairs) of DNA, and describe its function in genetic inheritance. What is DNA: http://www.statedclearly.com/what-is-dna/

DNA StructureDNA is a long polymer made up of many smaller units called nucleotidesA nucleotide consists of a phosphate group, 5 carbon sugar and nitrogenous baseDNA contains 4 nitrogenous bases

DNA FunctionDNA stores the genetic code which carries the instructions for making proteins and inheritance

3.2 Describe the basic process of DNA replication and how it relates to the transmission and conservation of the genetic code.

3.2: Explain the basic processes of transcription and translation, and how they result in the expression of genes. Distinguish among the end products of replication, transcription, and translation.Transcription takes place in the nucleus; transcribes message from DNA Translation takes place at the ribosome in the cytoplasm; translates mRNA to tRNA to amino acid

3.3: MutationsExplain how mutations in the DNA sequence of a gene may or may not result in phenotypic change in an organism.

3.3: MutationsExplain how mutations in gametes may result in phenotypic changes in offspring.

3.4: DominanceDistinguish among observed inheritance patterns caused by several types of genetic traits (dominant, recessive, codominant, sex-linked, polygenic, incomplete dominance, multiple alleles).

DOMINANT/RECESSIVE INCOMPLETECODOMINANT

3.4: Polygenic Traits

Traits that are controlled by more than one gene. In humans height, weight and skin color are polygenic.

3.4: Multiple Alleles & Codominant

Blood type is an example of multiple alleles:ABO codominance:AB blood

Sex-linked traitsUsually passed on by the mother who is a carrier; usually affects males

3.5 Describe how Mendel’s laws of segregation and independent assortment can be observed throughpatterns of inheritance (e.g., dihybrid crosses).

3.6 Use a Punnett Square to determine the probabilities for genotype and phenotype combinations inmonohybrid crosses.• Cross 2 homozygous

dominant or 2 recessive and the offspring will be the same as the parents.

• Cross 2 heterozygous parents and the probability is a 3-1 ratio for the dominant trait to be expressed. The probability for genotype is a 1:2:1 ratio