Human Cells Unit 1 KA 3

Question 1

What is a Gene?

Answer 1

A gene is a section of DNA which codes for a protein

Question 2

What is Gene expression?

Answer 2

Gene expression is the process where specific genes are activated to produce a required protein

Question 3

How many Genes in a cell are actually expressed?

Answer 3

Only a fraction of the genes in a cell are actually expressed

Question 4

What two stages make up the process of Gene expression?

Answer 4

1) Transcription
2) Translation

Question 5

1

What is Transcription?

Answer 5

Transcription is the copying of DNA code into mRNA

Question 6

Where does Transcription occur?

Answer 6

Transcription of DNA into mRNA happens in the nucleus

Question 7

What are Introns?

Answer 7

Introns are non-coding regions of genes

They are REMOVED

(Introns arent in -> Out)

Question 8

What are Exons?

Answer 8

Exons are coding regions of genes

Spliced together to form mature transcript

(Exons are excellent -> In)

Question 9

Where are Introns found?

Answer 9

Introns are found between Exons

Question 10

Why might Introns be spliced differently?

Answer 10

Introns may be spliced differently in different tissues

Question 11

How can different proteins be expressed from one gene?

Answer 11

Different proteins can be expressed from one gene as a result of altrernative RNA splicing

Question 12

How can different mature mRNA transcripts be produced from the same primary transcript?

Answer 12

Different mature mRNA transcripts can be produced from the same primary transcript depending on which exons are retained

Question 13

Where does the mature transcript of mRNA move?

Answer 13

The mature transcript of mRNA moves from the nucleus to a ribosome

(Through the cytoplasm)

Question 14

2

What is Translation?

Answer 14

Translation is when the code is used to make a protein using tRNA to carry amino acids

Question 15

What chemical is involved in Gene expression?

Answer 15

The chemical RNA is involved in gene expression

Question 16

The order of ____ on DNA determines the sequence of ____ ____ that are joined together to produce a ____

(Fill in the blanks)

Answer 16

The order of bases on DNA determines the sequence of amino acids that are joined together to produce a protein

Question 17

What does the sequence of Amino acids determine?

Answer 17

The sequence of amino acids determines the
structure, shape and function of the protein produced

Question 18

How many strands of nucleotides are in RNA?

Answer 18

There are one strand of nucleotides in RNA

(RNA is single stranded)

Question 19

What is the purpose of RNA?

Answer 19

The purpose of RNA is to provide a link between DNA and protein synthesis

Question 20

What does an RNA nucleotide contain? (3)

Answer 20

1) Ribose sugar
2) Phosphate
3) Base

Question 21

What four bases are found in an RNA nucleotide?

Answer 21

1) Adenine
2) Uracil
3) Cytosine
4) Guanine

Question 22

What does mRNA do?

(messenger RNA)

Answer 22

mRNA carries a copy of DNA code from the nucleus to the ribosome

Question 23

Where is mRNA found?

Answer 23

mRNA is found the nucleus and the cytoplasm

Question 24

What is each triplet of bases on mRNA called?

Answer 24

Each triplet of bases on mRNA is called a codon

Question 25

What is a **Codon** made up of?

Answer 25

A codon is made up of introns and exons | (Exons spliced to form mature mRNA)

Question 26

What does each **Codon** do?

Answer 26

Each codon codes for a specific amino acid

Question 27

Where is **mRNA** translated into proteins? by what?

Answer 27

mRNA is translated into proteins by **ribosmomes** in the **cytoplasm**

Question 28

What does **rRNA** do? | (ribosomal RNA)

Answer 28

rRNA and proteins form a ribosome

Question 29

Where is **rRNA** found?

Answer 29

rRNA is found in the **ribosome**

Question 30

What does **tRNA** do? | (transfer RNA)

Answer 30

tRNA carries a specific amino acid

Question 31

Where is **tRNA** found?

Answer 31

tRNA is found in the **cytoplasm**

Question 32

Why is **tRNA** folded?

Answer 32

tRNA is folded due to complemetary base pairing

Question 33

What is each triplet of bases on **tRNA** called?

Answer 33

Each triplet of bases on tRNA is called an **anti-codon**

Question 34

What does each **Anti-codon** do?

Answer 34

Each anti-codon binds to a specifc **mRNA codon**

Question 35

Why does **tRNA** have attachment sites?

Answer 35

tRNA has attachment sites to pick up **amino acids**

Question 36

What is on the two ends of **tRNA**?

Answer 36

1) The **anti-codon** (binds to mRNA codon) 2) **Attachment site** (for specific amino acid)

Question 37

What is an **mRNA** codon complementary to?

Answer 37

An mRNA codon is complementary to the triplet of bases on the original DNA strand

Question 38

What is a **tRNA** anti-codon complementary to?

Answer 38

A tRNA anti-codon is complementary to a mRNA codom

Question 39

Where is **RNA** found?

Answer 39

RNA is found in the **nucleus** and the **cytoplasm** | (DNA is only found in the nucleus)