Inheritance (Menelian Genetics) - Genetics

Front 1

Explain Mendel's experiments applied to genetics

Back 1

7 character pairs chosen from garden peas used for breeding experiments. Chose characters of pea plants with noticeable properties through specific generations.

Front 2

Why were those specific characteristics chosen

Back 2

characters with a clear distinction required

Front 3

Why did Mendel use true breeding lines

Back 3

produce the same properties across generations

Front 4

What 2 methods were used to breed the pea plants

Back 4

1. Cross pollination via pollen transfer from brush and removing the anther from the recipient plant
2. Selfing via transfer of pollen to stigma, ensures pollen from own anther isn't used for self pollination

Front 5

What were the difference between the two

characteristics in each experiment

Back 5

One was dominant, other was recessive.

Smooth seeds x wrinkled seeds would produce F1 generation 100% smooth seeds

Front 6

Explain Mendel's first law

Back 6

Principle of segregation of Mendelian factors:

The two members of a gene pair (alleles) segregate (separate) from each other in the formation of gametes. Half the gametes carry one allele, and the other half carry the other allele.

Front 7

What were Mendel's 2 conclusions from his experiments

Back 7

1. Hereditary is determined by particles
2. Principle of segregation

Front 8

What are the monohybrid F2 cross ratio of

characteristics

Back 8

Dominant: 3

Recessive: 1

Front 9

What was different about Mendel's dihybrid

experiments compared to his first?

Back 9

Genes were on the same chromosome, they go together during Anaphase

Front 10

Explain the principle of independent assortment

Back 10

When two or more characteristics are inherited, individual hereditary factors assort

independently during gamete production, giving different traits an equal opportunity of occurring together

Front 11

What is a test-cross

Back 11

breeding of an individual expressing a dominant phenotype with a phenotypically recessive individual, in order to determine the

zygosity of the former by analyzing proportions of offspring phenotypes.

Front 12

What is a null hypothesis (Ho)

Back 12

States there is no real difference between

observed data and expected data, X(2) tests this

Front 13

How to perform a X(2) test

Back 13

1. List observed numbers (O)
2. Calculated expected numbers for each class (E)
3. O - E
4. (O - E)2
5. (O - E)2 / E
   
6. X(2) total of all values
7. determine the number of class
8. use X(2) and n value to calculate probability that deviation of observed from expected values are due to chance

Front 14

What are the test cross ratios of characteristics

Back 14

1 : 1 : 1 : 1

Front 15

How to test the null hypothesis

Back 15

The larger the X(2) the less likely to occur by chance (smaller probability)

The more degrees of freedom, more variation

expected

Front 16

Examples of autosomal dominant inherited

diseases

Back 16

Huntington's disease - neurodegenerative

Neurofibromatosis

Front 17

Examples of autosomal recessive inherited

diseases

Back 17

Cystic fibrosis - most commonest (1/1700) Lungs fail to transport Cl- ions

Sickle cell anaemia