Exam 4 Review Outline F 2017

These flashcards cover key concepts in genetics and molecular biology based on the lecture notes from Exam 4 Review Outline F 2017.

Gene

A segment of DNA that codes for a specific protein or trait.

Fundimental unit of heredity

Allele

Different forms of a gene that can exist at a specific locus.

Phenotype

The observable physical or biochemical characteristics of an organism.

Genotype

The genetic constitution of an individual, often expressed in terms of alleles.

Law of Segregation

Mendel's law stating that allele pairs segregate during gamete formation.

Law of Independent Assortment

Mendel's law stating that genes for different traits assort independently of one another.

Monohybrid Cross

A genetic cross between individuals that involves one pair of contrasting traits.

Dihybrid Cross

A genetic cross that examines the inheritance of two different traits.

Testcross

A cross between an individual with an unknown genotype and a homozygous recessive individual.

Complete Dominance

A form of dominance where the dominant allele completely masks the effect of the recessive allele.

Incomplete Dominance

A genetic situation in which one allele does not completely dominate another allele.

Co-Dominance

A situation in which both alleles in a heterozygote are fully expressed.

Epistasis

A form of gene interaction where one gene masks or modifies the expression of another gene.

Polygenic Traits

Traits that are controlled by multiple genes.

Linked Genes

Genes that are located close to each other on the same chromosome and tend to be inherited together.

Recombinant

An offspring whose phenotype differs from that of the parents due to recombination.

Linkage Map

A map that shows the relative positions of genes on a chromosome based on recombination frequencies.

Sex-Linked Genes

Genes that are located on the sex chromosomes, usually the X chromosome.

Pedigree

A diagram that shows the occurrence and appearance of phenotypes of a particular gene or organism from one generation to the next.

Dominant Allele

An allele that is fully expressed in the phenotype of a heterozygote.

Recessive Allele

An allele that is only expressed in the phenotype when in a homozygous state.

Barr Bodies

Inactivated X chromosomes in females that ensure dosage compensation.

Semi-Conservative Replication

The process of DNA replication where each daughter molecule consists of one old strand and one newly synthesized strand.

Telomere

The repetitive DNA at the end of a eukaryotic chromosome that protects it from deterioration.

Telomerase

An enzyme that adds nucleotides to the ends of telomeres, helping to maintain their length.

Chargaff's Rule

The principle that DNA from any cell of any organism contains equal amounts of adenine and thymine, and equal amounts of cytosine and guanine.

Purine

A type of nitrogenous base in DNA and RNA, specifically adenine (A) and guanine (G).

Pyrimidine

A type of nitrogenous base in DNA and RNA, specifically cytosine (C), thymine (T), and uracil (U).

Transcription

The process of copying a segment of DNA into RNA.

Translation

The process by which a protein is synthesized from the information contained in mRNA.

Operator

A segment of DNA that regulates the expression of genes by binding repressors.

Operon

A group of genes that operate together and are controlled by a single promoter.

Enhancers

Short regions of DNA that can be bound by proteins to increase the likelihood of transcription.

Epigenetics

The study of changes in gene expression that do not involve changes to the underlying DNA sequence.