DNA and Genetics Lecture Review

These flashcards cover important concepts from the lecture on DNA structure and genetics, including terminology, processes, and definitions relevant for understanding molecular biology and inheritance.

Sugar-phosphate backbone

Forms the outer framework of DNA and provides stability through strong covalent bonds.

Antiparallel strands

DNA strands run in opposite directions (5'→3' and 3'→5'), essential for enzyme function like DNA polymerase.

Role of helicase

Unwinds DNA by breaking hydrogen bonds between base pairs.

Semiconservative replication

Each new DNA molecule contains one original strand and one new strand, preserving genetic accuracy.

Uracil

A nitrogenous base that distinguishes RNA from DNA, reflecting structural and functional differences.

Components of a nucleotide

Sugar, phosphate group, and nitrogenous base.

Hydrogen bonds in DNA

Allow strands to separate easily while maintaining overall stability.

Frameshift mutation

Occurs when a nucleotide is deleted, altering the downstream amino acids and often resulting in nonfunctional proteins.

Definition of interphase

The phase where cells grow, perform functions, and prepare for division.

G1 phase

The phase where the cell grows and carries out normal functions.

S phase

The phase in which DNA is replicated.

Meiosis purpose

To produce haploid gametes and maintain species chromosome number after fertilization.

Dominant allele

An allele that is expressed with only one copy.

Pedigree

A diagram that shows inheritance patterns in a family.

Central Dogma

The process describing the flow of genetic information: DNA → RNA → Protein.

Transcription

The process where DNA is copied into mRNA.

Silent mutation

A mutation that does not change the amino acid due to the redundancy of the genetic code.

Incomplete dominance

A genetic situation in which one allele does not completely dominate another, resulting in a blended phenotype.

Crossing over

The exchange of DNA between homologous chromosomes, increasing genetic variation.

Phenotype

Observable traits of an organism.

Genotype

The genetic makeup of an organism.

Heterozygous

Having two different alleles for a particular gene; the dominant allele is expressed.

Law of Segregation

States that alleles separate during gamete formation, ensuring each gamete receives only one allele.