Bio Unit 5 test

Question 1

Who discovered the structure of DNA?

Answer 1

James Watson and Francis Crick

Question 2

Who was the woman who helped the 2 men discover the structure of DNA and how?

Answer 2

Rosalind Franklin, she took Photo 51

Question 3

What is the small chunk of the DNA called?

Answer 3

Nucleotide

Question 4

What is a nucleotide made of- draw it?

Answer 4

Phosphate, sugar, nitrogen containing base

Question 5

What are the different stages of protein synthesis?

Answer 5

Transcription and translation

Question 6

Where do the different stages of protein synthesis take place?

Answer 6

Transcription in the nucleus. Translation in a ribosome.

Question 7

What happens in the first stage of protein synthesis?

Answer 7

In transcription, the DNA unzips, the mRNA matches bases with the DNA to copy the instructions and then the mRNA leaves the nucleus to find a ribosome for the next stage.

Question 8

What happens in the second stage of protein synthesis?

Answer 8

After finding a ribosome the mRNA enters it and translation takes place. In translation the ribosome translates the codons into Amino Acids (creating them)

Question 9

What is a mutation?

Answer 9

It is a change in the DNA sequence

Question 10

What are the 2 different types of mutations and what do they do?

Answer 10

Substitution where one base is substituted/changed. Frameshift where one base is deleted or one base is added

Question 11

What are the different things that can happen in a substitution mutation

Answer 11

Missense- where the Amino Acid is changed
Silent- where the Amino Acid isn’t changed
Nonsense- when an early STOP is caused

Question 12

What are the different things that can happen in frameshift mutation?

Answer 12

No matter what all of the Amino Acids down the line after the frameshift will be changed.
- Insertion- When a base is added (extra letter)
- Deletion- When a base is deleted (missing letter)

Question 13

What is a codon?

Answer 13

Pair of 3 letters

Question 14

What is heterozygous and homozygous?

Answer 14

Heterozygous is when they are different letters and homozygous is when they are both the same letter

Question 15

What is a phenotype and what is a genotype

Answer 15

The phenotype is the physical appearance of the trait and the genotype is the letters that code for it

Question 16

What are the different Non Mendelian genetics

Answer 16

• Incomplete dominance
• Codominance
• Multiple alleles
• Sex-linked traits

Question 17

What is a pedigree?

Answer 17

It is a tool used to study inherited diseases. It helps to show the risk of disease in future generations.

Question 18

In a pedigree what does a circle represent?

Answer 18

Female

Question 19

In a pedigree what does a square represent?

Answer 19

Male

Question 20

In a pedigree what does shaded mean?

Answer 20

They are infected with the disease

Question 21

What does autosomal mean?

Answer 21

Autosomal means the disease is not linked to the sex of an individual.

Question 22

What does X-linked mean?

Answer 22

X-linked means the disease is linked to the sex of an individual

Question 23

What does recessive mean in a pedigree?

Answer 23

It means the disease is linked to a recessive gene (is a recessive gene)

Question 24

What does dominant mean in a pedigree?

Answer 24

It means the disease is linked to a dominant gene (is a dominant gene)

Question 25

What is natural selection?

Answer 25

It is the process where organisms with traits better suited to their environment are more likely to survive and reproduce.

Question 26

What are the 3 types of natural selection? - draw them

Answer 26

Directional, stabilizing, disruptive.

Question 27

What are the 3 different reasons for adaptation (with examples)?

Answer 27

Adaptation for food (resources) → stronger sense of smell Adaptation for reproduction → larger tusks on male elephants Adaptation for protection → blubber to keep warm

Question 28

What are the 4 possible bases in a nucleotide

Answer 28

Adenine, Guanine, Cytosine, Thymine