Topic 3 - Genetics

Question 1

Examples of genetic differences that shows variation in population

Answer 1

Natural eye colour

Natural hair colour

Question 2

Examples of genetic and environmental differences that explains variation in population

Answer 2

Skin colour
Height
Weight
Exam performance

Question 3

Environmental factors that show variation in a population

Answer 3

Piercings
Tattoos
Scars

Question 4

Example of homozygous recessive

Answer 4

bb

Question 5

Example of homozygous dominant

Answer 5

BB

Question 6

Example of heterozygous

Answer 6

Bb

Question 7

What is genotype?

Answer 7

The alleles we have

Question 8

What is phenotype?

Answer 8

The characteristics we have determined from alleles

Question 9

What is an allele?

Answer 9

A different form of the same gene eg B = brown eye. b = blue eye

Question 10

What are gametes?

Answer 10

Sex cells. Sperm and egg cells. Haploid cells

Question 11

How many chromosomes does a zygote have?

Answer 11

46. Diploid

Question 12

What is meiosis?

Answer 12

Cell division only in the reproductive organs

Question 13

What does meiosis produce?

Answer 13

Four daughter cells. Each with half the number of chromosomes which results in genetically different haploid gametes.

Question 14

Describe the DNA structure

Answer 14

Double helix. Strands linked with complimentary base pairs joined together by weak hydrogen bonds. Sugar phosphate backbone.

Question 15

What are the complimentary base pairs?

Answer 15

A adenine + T thymine. C cytosine + G guanine

Question 16

What is the genome?

Answer 16

The entire DNA of an organism

Question 17

What is a gene?

Answer 17

A section DNA molecule that codes for a specific protein.

Question 18

What is a chromosome?

Answer 18

Long coiled up molecules of DNA found in the nucleus of eukaryotic cells.

Question 19

Dominant

Answer 19

Dominant alleles will determine what characteristic is present

Question 20

Recessive

Answer 20

Both alleles must be recessive for the organism to display the characteristic

Question 21

What is a zygote?

Answer 21

A fertilised egg from the sperm fusing with the egg.

Question 22

what chromosome do males have?

Answer 22

XY

Question 23

What chromosome do females have?

Answer 23

XX

Question 24

What is monohybrid inheritance?

Answer 24

The inheritance of a single characteristic

Question 25

What are most phenotype features the result of?

Answer 25

Múltiples genes rather than a single gene inheritance.

Question 26

What is genetic variation that influence phenotype?

Answer 26

Different characteristics as a result of mutation and sexual reproduction

Question 27

What is environmental variation that influence phenotype?

Answer 27

Different characteristics caused by an organisms environment

Question 28

What was the outcome of the human genome project?

Answer 28

It has helped identify 1800 genes related to disease, which has huge benefits for medicine

Question 29

Prediction and prevention of diseases (medical application for the projects research)

Answer 29

If doctors knew what genes predisposed people to what diseases, we could get individually tailored advice on best diet and lifestyle to avoid problems. Doctors could check us regularly to ensure early treatment if we develop a disease.

Question 30

Testing and treatment for inherited disorders (medical application for the projects research)

Answer 30

Inherited disorders caused by faulty alleles in a persons genome. From the HGP scientists can identify genes and alleles that cause an inherited disorder a lot quicker. Once allele identified, people can get tested for it. Better treatments could develop or cure disease.

Question 31

New and better medicines (medical application for the projects research)

Answer 31

HGP has shown common genetic variations and how bodies react to diseases and treatments for them. Scientists can now design new drugs tailored to a particular genetic variation. More effective treatments can be made with fewer side affects.

Question 32

How does genetic variation arise within a population?

Answer 32

There’s usually extensive genetic variation within a population of a species and these arise through mutations

Question 33

Do mutations have any affect on phenotype?

Answer 33

Genetic mutations have no effect to phenotype. Some mutations have a small effect on phenotype. Rarely a single mutation will significantly affect the phenotype.