DNA Replication, Repair, and Recombination

These flashcards cover key concepts related to DNA replication, repair, and recombination, providing essential definitions and mechanisms important for the understanding of genetics.

The process by which a cell makes an identical copy of its DNA before cell division is called __.

DNA replication.

Changes in DNA sequences that can occur due to replication errors or damage are called __.

Mutations.

The __ is the structure where DNA is replicated, consisting of a leading and a lagging strand.

Replication fork.

The enzyme responsible for synthesizing new DNA strands is called __.

DNA polymerase.

During DNA replication, the strand is synthesized continuously, while the strand is made in fragments called Okazaki fragments.

Leading; lagging.

The high accuracy of DNA replication is maintained by several proofreading mechanisms, with DNA polymerase allowing for __ correction of mistakes.

Exonucleolytic.

In eukaryotes, specialized proteins known as __ bind single-strand DNA to prevent it from forming secondary structures during replication.

Single-strand binding proteins.

The mechanism that repairs double-strand breaks in DNA using information from a homologous DNA strand is called __.

Homologous recombination.

The specialized enzyme responsible for inserting a transposon into new DNA sites is called __.

Transposase.

The ends of chromosomes, known as __, are essential for protecting genetic information and preventing chromosome fusion.

Telomeres.

DNA repair that involves the removal of a damaged section of DNA and filling in the gap with new nucleotides is known as __ repair.

Nucleotide excision.

The disorder __ is linked to deficiencies in DNA repair mechanisms, resulting in increased cancer risk.

Ataxia-telangiectasia.

The presence of mismatched base pairs in DNA made during homologous recombination can lead to __ during meiosis.

Gene conversion.

Transposition mechanisms involve mobile genetic elements moving within a host genome through __ mechanisms.

Cut-and-paste or replicative.

During DNA replication, the enzyme responsible for creating RNA primers on the lagging strand is called __.

Primase.

The type of recombination that serves as a mechanism for antigen diversity during immune responses is called __ recombination.

V(D)J.

The specialized complex that recognizes and repairs mismatches in the newly synthesized DNA is known as __.

Mismatch repair system.

Many transposons replicate through an intermediate RNA stage called __.

Retrotransposons.

In humans, a significant number of mutations and genetic disorders are associated with the __, which are repetitive sequences in the genome.

Nonretroviral retrotransposons.

The phenotypic variations resulting from transposon activity in the genome are largely responsible for __ in evolution.

Genetic diversity.

Chromatin consists of

very long double stranded DNA molecules, nearly an equal mass of rather small basic proteins termed histones, as well as smaller amounts of nonhistone proteins, and a small quantity of ribonucleic acid (RNA)