DNA + Replication

Question 1

What are introns?

Answer 1

Parts of DNA that doesn’t code for anything

Question 2

What are exons?

Answer 2

Parts of DNA that do code

Question 3

What is the chiasmata?

Answer 3

Where the chromosomes cross over.

Question 4

How to obtain accuracy when calculating mitotic index?

Answer 4

Examine large samples.
Repeat count.
Count only whole cells.

Question 5

Mitotic index calculation

Answer 5

Number of cells undergoing mitosis / total cells in sample x 100

Question 6

What is genetic diversity?

Answer 6

The total number of genetic characteristics in the genetic makeup of a species.

Question 7

How does genetic diveristy occur?

Answer 7

Through mutations (DNA replication or mutagenic agents).
During meiosis.

Question 8

What occurs during meiosis that causes genetic diversity?

Answer 8

Chromosome non disjunction
Crossing over
Independent segregation

Question 9

How many bonds between cytosine and guanine?

Answer 9

3 hydrogen bonds

Question 10

How many bonds between adenine and thymine?

Answer 10

2 hydrogen bonds

Question 11

What does helicase do?

Answer 11

Unwinds the double helix.
Separates the strands by breaking hydrogen bonds.

Question 12

What does DNA polymerase do?

Answer 12

Links nucleotides together to form new strands.

Question 13

Why is the triplet code degenerate?

Answer 13

Multiple colons can code for the same amino acid during protein synthesis

Question 14

What are the 3 main facts about the triplet code?

Answer 14

It is degenerate.
It is non overlapping.
It is universal.

Question 15

DNA

Answer 15

Double helix.
Thymine.
Deoxyribose sugar.
Stores genes.
Long.
Antiparallel (read 5 to 3 direction)

Question 16

RNA

Answer 16

Ribose sugar.
Uracil.
Shorter.
Transfers DNA to ribosomes.
Single strand.

Question 17

What bond is between the base and sugar of DNA?

Answer 17

Glycosidic

Question 18

What bond is between the phosphate and sugar of DNA?

Answer 18

Ester bond

Question 19

What bond is between 2 nucleotides in DNA?

Answer 19

Phosphodiester bond

Question 20

Which bases are purine (double ringed)?

Answer 20

Adenine
Guanine

Question 21

Which bases are pyrimidine (single ringed)?

Answer 21

Thymine
Cytosine

Question 22

Process of semi conservative DNA replication?

Answer 22

Helicase unwinds DNA helix.
Hydrogen bonds break.
New DNA nucleotides are attracted to template strand.
DNA polymerase joins nucleotides. Creates new phosphodiester bonds. Condensation reaction.

Question 23

Process of binary fission

Answer 23

Replication of circular DNA
Replication of plasmids.
Division of cytoplasm.
Identical daughter cells.

Question 24

Process of viral replication

Answer 24

Attachment proteins attach to receptors on host cell.
Viral nucleic acid enters cell.
Nucleic acid is replicated. Reverse transcription.
Cell produces enzymes.
Virus is released from cell.

Question 25

What is the Locus?

Answer 25

The position of the gene on the chromosome

Question 26

Why do cells divide?

Answer 26

For growth and replacement. For asexual reproduction. For gametes for sexual reproduction.

Question 27

Mitosis

Answer 27

Genetically identical Growth and replacement Asexual 2 cells

Question 28

Meiosis

Answer 28

Genetically different 4 cells Gametes (haploid) Needed for sexual

Question 29

What is transcription?

Answer 29

The process of copying a segment of DNA to create a complementary copy called a single stranded mRNA.

Question 30

Process of transcription

Answer 30

Part of DNA unwinds. Exposes the gene. Free nucleotides pair up with complementary bases on template strand. Hydrogen bonds Sugar phosphate groups bind by RNA polymerase. Hydrogen bonds break. Double strand of DNA forms. Single stranded mRNA leaves the Nucleus via a pore in the envelope.

Question 31

Process of splicing

Answer 31

Introns are removed from mRNA

Question 32

Process of translation

Answer 32

When mRNA is in the cytoplasm, a ribosome attaches at the start codon. A tRNA molecule (containing an antibodies complementary to the mRNAs codon) binds. It also carries a specific amino acid. Moves to next codon. Amino acids join by peptide bonds and require ATP. Polypeptide chain is formed. Released when ribosomes detaches at stop codon.

Question 33

What is the division of the cytoplasm called?

Answer 33

Cytokinesis

Question 34

Stages of cell division?

Answer 34

Interphase Prophase Metaphase Anaphase Telophase

Question 35

Interphase

Answer 35

Chromosomes extend. Chromosomes replicate. Centiroles replicate. Nucleolus visible.

Question 36

Prophase

Answer 36

Chromosomes condense. Nuclelous disappears. Envelope breaks down. Centrioles migrate apart. Spindle fibers form.

Question 37

Metaphase

Answer 37

Chromosomes align in the equator. Chromosomes are attached to spindle fibers.

Question 38

Anaphase

Answer 38

Centromere splits. One chromatid from each chromosome moves to opposite poles.

Question 39

Telophase

Answer 39

Nuclear membranes form. Spindles disappear. Chromosomes extend.

Question 40

When does crossing over occur?

Answer 40

Prophase 1

Question 41

When does independent segregation occur?

Answer 41

Metaphase 1

Question 42

What is eukaryotic DNA like?

Answer 42

Linear. Wrapped around histones. Contains introns.

Question 43

What is prokaryotic DNA like?

Answer 43

It is circular. Has no histones. Has no introns.

Question 44

Structure of DNA?

Answer 44

Polymer of nucleotides. Nitrogenous bases and deoxyribose phosphate. Bound around histones.