External Exam Revision

Question 1

What is DNA?

Answer 1

• Carries information coded in genes

Question 2

What is a Eukaryotic Cell?

Answer 2

A cell or organism that has a defined nucleus

Question 3

What is a Prokaryotic Cell?

Answer 3

A cell or organism that does not have a defined nucleus

Question 4

What does DNA look like in Eukaryotic Cells?

Answer 4

DNA is visible as a grainy substance without detail

Question 5

What is the grainy substance DNA is seen in Eukaryotic Cells?

Answer 5

Chromatin

Question 6

What does DNA look like in Karyotype Cells?

Answer 6

Jumbled cluster of chromosomes during nuclear division

Question 7

What is the Endosymbiotic Theory?

Answer 7

DNA in both mitochondria and chloroplasts are similar to the single, circular chromosomes in Prokaryotic cells

Question 8

What does the Endosymbiotic Theory suggest?

Answer 8

Eukaryotic cells were developed when a bacterial cell was ingested by another primitive prokaryotic cell

Question 9

What is Maternal Inheritance?

Answer 9

Mitochondria and chloroplasts can only arise from pre-existing mitochondria and chloroplasts

Question 10

What is an example of Maternal Inheritance?

Answer 10

Flowering plants: chloroplasts are inherited from Female plants

Question 11

What are Prokaryotes?

Answer 11

Distinguished by lack of nucleus and membrane-bound organelles

Question 12

Example of a Prokaryote:

Answer 12

Bacteria

Question 13

What does DNA look like in Prokaryotes?

Answer 13

One single circular chromosome with direct contact with the cytoplasm

Question 14

What are the 4 bases?

Answer 14

Adenine (A)
Thymine (T)
Guanine (G)
Cytosine (C)

Question 15

Which bonds with Adenine (A)

Answer 15

Thymine (T)

Question 16

Which bonds with Cytosine (C)

Answer 16

Guanine (G)

Question 17

How is RNA different to DNA?

Answer 17

1. RNA is single-stranded
2. Base Thymine replaced by the base Uracil (U)
3. Ribose sugar replaces the Deoxyribose of DNA

Question 18

What is DNA Replication?

Answer 18

DNA carries information from generation to generation / allows cells to undergo growth, repair, and reproduce

Question 19

What must happen to a cell before DNA Replication?

Answer 19

• Replicate their DNA

Question 20

What occurs during DNA Replication?

Answer 20

Begins with DNA helicase (enzyme) unzips long, helical molecule of double stranded DNA by breaking weak hydrogen bonds between nucleotides

Question 21

What is the outcome of DNA Replication?

Answer 21

Two double helix DNA molecules each containing of one original parental strand and a new strand

Question 22

What is Meiosis?

Answer 22

Form of eukaryotic cell division which creates gametes

Question 23

What is the result of Meiosis?

Answer 23

Production of 4 genetically different daughter cells

Question 24

What is the difference between Meiosis I and II?

Answer 24

Meiosis I - chromosome pairs produce 2 cells

Meiosis II - chromatids of each chromosome separate to produce 4 cells

Question 25

What is Interphase?

Answer 25

• First stage in Meiosis I and II
• Chromosomes cannot be distinguished under light
• Chromosome replication occurs
• Produces identical sister chromatids

Question 26

What is Prophase I (Also referred to as Crossing Over / Synapsis)?

Answer 26

• Chromosomes condense and nuclear envelope breaks down

- Homologous chromosome pairs bind firmly together along length