Ch14 Study Guide Homework Flashcards

Flashcards contatining questions and answers related to Ch14 Study Guide Homework

What are the key differences between DNA and RNA?

DNA contains deoxyribose sugar, uses thymine, and is typically double-stranded. RNA contains ribose sugar, uses uracil, and is typically single-stranded.

In which step of the cell cycle is DNA replication completed?

Completed during the S phase (synthesis phase) of the cell cycle.

What is the goal of DNA replication?

To create two identical DNA molecules from one original DNA molecule.

At the end of replication, how many DNA molecules are present, and what are the percentages of old and new strands?

Two DNA molecules; each is 50% old (original strand) and 50% new (newly synthesized strand).

Which bases pair together in DNA? How does this differ in RNA?

In DNA, adenine (A) pairs with thymine (T), and cytosine (C) pairs with guanine (G). In RNA, adenine (A) pairs with uracil (U).

The process by which new molecules of DNA are formed is called __.

Replication

Strands of DNA are held together by hydrogen bonds between the __.

Nitrogenous bases

The sugar in RNA is __.

Ribose

The sugar in DNA is __.

Deoxyribose

Nucleotides come in four different forms; the __ are the parts of the nucleotides that can vary.

Nitrogenous bases

Describes the arrangement of the sides of the DNA molecule?

Antiparallel (strands run in opposite directions, 5' to 3' and 3' to 5').

If a DNA molecule is found to be composed of 40% thymine, what percentage of guanine would be expected?

10%

What molecule is found on RNA but not DNA?

Uracil

The ends of the linear chromosomes are maintained by __.

Telomeres

What enzyme covalently connects segments of DNA?

DNA ligase

How do the leading and the lagging strands differ?

The leading strand is synthesized continuously, while the lagging strand is synthesized in short fragments (Okazaki fragments).

The experiments by Hershey and Chase helped confirm that DNA was the hereditary material on the basis of the finding that:

Radioactive DNA from viruses entered bacterial cells, indicating DNA is the genetic material.

If one strand of DNA has the nitrogen base sequence TAGCA, the sequence of bases on the other strand must be __

ATCGT

What is meant by the description 'antiparallel' regarding the strands that make up DNA?

The strands run in opposite directions (5' to 3' and 3' to 5').

What enzyme catalyzes the elongation of a DNA strand in the 5' 3' direction?

DNA polymerase

In eukaryotes, what is the DNA wrapped around?

Histones

What kinds of proteins are involved during the formation of the replication fork?

Helicase, single-strand binding proteins, topoisomerase

What does the enzyme primase synthesize?

RNA primer