Biology

Question 1

Describe the Structure of DNA

Answer 1

DNA is a double stranded, double helix molecule

Question 2

Where is DNA found in the Cell?

Answer 2

DNA is found in the nucleus of the cell. It is arranged as chromosomes

Question 3

What is a gene?

Answer 3

A gene is a section of a chromosome that code for a particular characteristic

Question 4

What is an Allele?

Answer 4

An allele is an alternate form of a gene e.g. if the gene is eye colour, the allele may be blue, brown or green eyes

Question 5

List some characteristics that are genetically controlled

Answer 5

• Eye Colour
• Ear Shape (ear lobe or no ear lobe)
• Hair Type
• Blood Type
• Nose Shape
• Dominant Hand
  Etc…

Question 6

List some characteristics that are environmentally controlled

Answer 6

• Hobbies
• Pierced ears
• Clothing Style
• Glasses
• Thin or Wide body shape
  Etc…

Question 7

What is a Dominant Allele?

Answer 7

An Allele that only has to appear once to show

Question 8

What is a Recessive Allele?

Answer 8

An Allele that has to appear both times to show (when no Dominant Alleles are present)

Question 9

What are homozygous alleles?

Answer 9

They are inherited alleles that are the same e.g. TT

Question 10

What are heterozygous alleles?

Answer 10

They are inherited alleles that are different e.g. Tt

Question 11

What is Genotype?

Answer 11

Describes the alleles present or genetic make up of an individual regarding a particular characteristic e.g. Bb or bb

Question 12

What is Phenotype?

Answer 12

Describes the physical appearance of an individual regarding a particular characteristic e.g. Curly hair or Straight hair

Question 13

What is a Genetically Inherited Disorder?

Answer 13

A genetic disorder is a disease caused by a faulty gene or chromosome.

Question 14

How are Genetic Disorders Inherited?

Answer 14

Genetic Disorders are either recessive or dominant so the Mum or the Dad will have 0, 1 or 2 of these and then it will depend on how the alleles match. This can be seen through use of a Punnet Square

Question 15

What is Selective Breeding?

Answer 15

Selective breeding is when humans choose parents to breed together. These parents have particular desirable characteristics and are likely to produce offspring that will have the same desirable characteristics

Question 16

Describe the stages of Selective Breeding

Answer 16

• Decide which characteristics you want to encourage
• Select parents that display high levels of the characteristics you are looking for
• Breed these individuals together
• Select the offspring that show high levels of the same characteristic and breed them
• Repeat this for many generations until the desired characteristic is shown across all the offspring and they shows off very high levels of it