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Flashcards in DNA Deck (36)
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0

Hydrogen bonds can form only between

Certain base pairs

1

Adenine can form only with

ThyminE

2

Guanine can form only with

Cytosine

3

What is base pairing

When hydrogen bonds can form only between certain base pairs

4

Why A=T And G=C

For every adenine in a double-stranded DNA molecule there had to be exactly one find me molecule; for each site is the molecule there was one wanting molecule

5

Prokaryotic cells lack

Nuclei and many of the organelles found in eukaryotes

6

What is the location of DNA in prokaryotic cells

Cytoplasm

7

What is the cells chromosome

Most prokaryotes have a single cellular DNA molecule that contains nearly all of the cells genetic information and this large DNA molecule is referred to as the cells chromosome

8

Eukaryotic DNA is generally located in the

Cell nucleus in the form of a number of chromosomes

9

Is the sentence true or false? Most prokaryotes contain a single, circular DNA molecule

True

10

Do all organisms have the same number of chromosomes

No the number of chromosomes very widely from one species to the next

11

is the following sentence true or false? The E. coli chromosome is longer than the diameter of an individual E. coli bacteria

True

12

What are chromatin

Eukaryotic chromosomes contain both DNA and protein, tightly packed together to form a substance called chromatin

13

What do chromatin consist of

DNA that is tightly coiled around proteins called histones

14

What do the DNA and histone molecules form

A bed like structure called a nucleosome. Nucleosomes pack with one another to form a thick fiber, which is shortened by a system of loops and coils

15

Why are individual chromosomes visible only during mitosis

During most of the cell cycle these fibers are disbursed into the nucleus so that individual chromosomes are not visible. During mitosis however the fibers of each individual chromosomes are drawn together forming the tightly packed chromosomes you can see through a light microscope in dividing cells.

16

Are changes in chromatin structure and histone DNA-binding associated with changes in gene activity

Yes

17

What are nucleosome's and their function

They seem to be able to fold enormous lengths of DNA into the tiny space available in the cell nucleus. This is such an important function at the histone proteins them selves have changed very little during evolution probably because mistakes in DNA folding could harm the cells ability to reproduce

18

Each strand of the DNA double helix has

All the information needed to reconstruct the other half by the mechanism of base pairing

19

The DNA molecule______ or unzips into two strands

Separates

20

Each strand serves as a_____ or model to produce new strands

Template

21

Two new_____ strands are produced, following the rules of _______

Complementary
Base pairing

22

Is the following sentence true or false? Eukaryotic chromosomes DNA replication begins at a single point in the chromosomes and proceeds into directions

False

23

The site where DNA replication and separation occur are called

Replication forks

24

What occurs when a molecule of DNA is unzipped

Hydrogen bonds between the base pairs are broken and the two strands of the molecule unwind

25

What is the complementary strand of bases for a strand with the bases TACGTT

ATGCAA

26

Is the following sentence true or false? Each DNA molecule resulting from replication has one original strand and one new strand

True

27

List two major roles of DNA polymerized in the process of DNA replication

Joins individual nucleotides to produce a DNA molecule
Proofreads each new DNA strand helping to maximize the odds that each molecule is a perfect copy of the original DNA

28

What is helicase

An enzyme that unwinds the double helix by technically slicing apart the loose hydrogen bonds

29

Is the top strands of the double helix called

The leading strand