Topic 3 - Genetics - Reproduction and DNA (3.1B - 3.6)

Question 1

what are 3 advantages of asexual reproduction

Answer 1

No mate is required, saving potential time and energy
identical offspring
faster than sexual reproduction

Question 2

advantages of sexual reproduction

Answer 2

variations in offspring can help to survive different environments meaning protection from diseases and survival of fittest scenarios

Question 3

disadvantages of asexual reproduction

Answer 3

no variation means that all parts of the colony are susceptible to disease. Species is only suited to one habitat

Question 4

disadvantages of sexual reproduction

Answer 4

takes time and energy to find a mate
non favourable genes might be passed onto the offspring
takes longer

Question 5

Explain the products of meiosis

Answer 5

four haploid, genetically different daughter cells. Meiosis products gametes.

Question 6

Describe the structure of DNA

Answer 6

Double Helix shaped strands, connected by bases containing hydrogen bonds. Each base is attached to a sugar molecule and a phosphate molecule.

Question 7

Define genome.

Answer 7

The entire genetic material of an organism. It is found in the nucleus and composed of DNA

Question 8

Define gene.

Answer 8

The section of DNA on a chromosome that codes for a specific sequence of amino acids, which later makes a specific protein

Question 9

Explain how DNA can be extracted from fruit

Answer 9

Put the strawberry into the plastic bag, seal it and crush for about 2 minutes.
Mix together with washing up liquid, salt and water in a beaker. This mixture will break down cell membranes and release the DNA. This creates an extraction liquid.
Add the extraction liquid to the bag with the strawberry. Mix together
Filter the strawberry mixture.
Pour ice-cold ethanol down the side of the beaker into the strawberry mixture, do not mix or stir. The DNA will separate out into this layer.
Within a few seconds you should see a white cloudy substance form in the clear layer above the strawberry mixture

Question 10

In a nucleotide diagram, what is the pentagon

Answer 10

the sugar

Question 11

in a nucleotide diagram, what is the rectangle

Answer 11

the base

Question 12

in a nucleotide diagram, what is the circle

Answer 12

the phosphate

Question 13

Describe the lysogenic pathway

Answer 13

Virus infects the host cell but the viral genes stay dormant. The cell makes lots of copies of itself through mitosis, all of these copies carry viral genetic material. Changes in the environment such as a chemical trigger cause the viral DNA to move to the lytic pathway to make new viruses.

Question 14

define genotype

Answer 14

the collection of alleles that determine an organisms characteristics