Topic 3 - Genetics

Question 1

What is meiosis?

Answer 1

When a cell divides twice to create four new cells

Question 2

Which cells are produced through meiosis?

Answer 2

Gametes(egg and sperm)

Question 3

Advantages of asexual reproduction

Answer 3

Lots of offspring can be produced quickly

Only one parent is needed

Question 4

Disadvantages of asexual reproduction

Answer 4

No genetic variation between offspring so disease can quickly spread through a population
The species may only be suited to one environment

Question 5

Advantages of sexual reproduction

Answer 5

Creates genetic variation in a population

Disease is less likely to spread through a population

Question 6

Disadvantages of sexual reproduction

Answer 6

Takes more time and energy than asexual

Require two parents

Question 7

What is a nucleotide made up of?

Answer 7

A sugar molecule, a phosphate molecule and a base.

Question 8

What does adenine bond with?

Answer 8

Thymine

Question 9

What does cytosine bond with?

Answer 9

Guanine

Question 10

What is a gene?

Answer 10

A section of a chromosome that codes for a specific sequence of amino acids, to make a protein

Question 11

What is a mutation?

Answer 11

A random change to an organism’s DNA base sequence

Question 12

What happens during the transcription stage of protein synthesis?

Answer 12

RNA Polymerase binds to a region of non-coding DNA in front of a gene. The two DNA strands separate and the RNA Polymerase moves along one of the strands. It uses the coding DNA to make mRNA. When made, the mRNA molecule moves out of the nucleus and joins the ribosome.

Question 13

What happens during the translation stage of protein synthesis?

Answer 13

Amino acids are brought to the ribosome by tRNA. The amino acids are brought in the order that matches the base triplets in the mRNA. The amino acids are joined together by the ribosome, this makes a protein.

Question 14

What is the difference between DNA and mRNA?

Answer 14

mRNA uses uracil instead of thymine as a base

Question 15

What is an alleles?

Answer 15

A different version of the same gene.

Question 16

Which blood type has a recessive phenotype?

Answer 16

O

Question 17

Which blood groups are codominant?

Answer 17

A and B

Question 18

What was the human genome project?

Answer 18

To create a complete map of the human genome

Question 19

What are the medical applications of the human genome project?

Answer 19

Prediction and prevention of diseases
Treating and testing for inherited disorders
New and better medicines

Question 20

What is a genome?

Answer 20

An organism’s complete set of DNA

Question 21

NOTE: you need to know how to do punnet squares

Answer 21

Page 38 in the CGP guide

Question 22

How can a genetic disorder be sex linked?

Answer 22

If the allele that causes it is found on the X or Y chromosome

Question 23

What causes a genetic order to be more common in men?

Answer 23

If it is carried on the X chromosome, then the faulty allele will always be able to express it self because men only have one X chromosome

Question 24

What is a nucleotide made up of?

Answer 24

One sugar molecule, one phosphate molecule and one base

Question 25

What is a non-coding region of DNA?

Answer 25

A region of DNA that does not code for any amino acids

Question 26

What causes genetic variation?

Answer 26

Mutations

Question 27

What is RNA Polymerase?

Answer 27

The enzyme involved in joining together RNA nucleotides to make mRNA

Question 28

How could a mutation in a none coding region if DNA affect the protein produced?

Answer 28

The mutation could make it easier or more difficult for the RNA Polymerase to bind to that region of DNA. How well the RNA Polymerase can bind to this region will affect how much mRNA is transcribed, therefore how much of the protein is produced.

Question 29

What did Mendal discover?

Answer 29

That characteristics of plants were passed on from one generation to the next. That some characteristics were dominant over others.

Question 30

How did Mendel make his discovery?

Answer 30

He bred two pea plants of different height, one tall and one small. All of the offspring were tall. He then bred two of these tall plants, 3 of the offspring were tall but one was small.

Question 31

How do you extract DNA from fruit cells?

Answer 31

Mash up the fruit and put it in a beaker containing a solution of detergent and salt. Filter the mixture through a funnel and filter paper. Add ice-cold alcohol to the mixture. The DNA will appear as a white precipitate which can be removed with a glass rod.