Cellular And Genetic Mechanisms 2

Question 0

What is the f2 for incomplete dominance

Answer 0

1:2:1

Question 1

Incomplete dominance what is it

Answer 1

When the dominant and recessive breed forming a mixture

Question 2

Co dominance what is the main example

And what do they do

Answer 2

Blood type
A and B are dominant to I
A and B are co dominant
Both expressed fully effects are additive

Question 3

Dihybrid gene interaction

What is it

Answer 3

When 2 gene loci (each with 2 alleles)

Interact to produce a single phenotype

Question 4

What is epistasis

Answer 4

Is the interaction between genes

Takes place when one gene is modified by one or several other genes

Question 5

recessive epistasis

What is it

Answer 5

Phenotypic ratio 9:3:4

Homozygous recessive allele makes the expression of the dominant allele for another gene

Question 6

Dominant epistasis

What is it

Answer 6

Phenotypic ratio 12:3:1

The dominant allele for a gene may mask the effect of another allele for another gene

Question 7

Duplicate recessive epistasis

What is it

Answer 7

9:7

Both dominant alleles from each gene required for pigment

Question 8

Duplicate genes with cumulative effect

What is it

Answer 8

9:6:1
Effect of both dominant alleles additive
Individual dominant alleles have same effect

Question 9

Duplicate dominant genes

What are they

Answer 9

15:1
Both dominant alleles have identical effect
No additive effect

Question 10

Dominant and recessive interaction

What is it

Answer 10

13:3
Dominant from one gene and recessive allele from other gene have the same phenotype
Gene A able to suppress expression at B gene

Question 11

Polygenic inheritance (multiple genes)
What is it

Answer 11

Many more then 2 genes to control something like height

Additive effect on phenotype

Question 12

Multiple alleles what are they

Answer 12

Single gene with more then 2 alleles
Different mutations cause this
Only 1 allele is expressed at any time

Question 13

Penetrance

Answer 13

Portion of individuals showing expected phenotype

Ie extra finger

Question 14

Expressivity

3 answers

Answer 14

Degree of expression of phenotype in an individual
Temp sensitive
Nutritional

Question 15

Retinoblastoma

How is it developed

Answer 15

Dominant allele, but not all develop Tumour
Incomplete penetrance in the population
When expressed there are different severity
Different expressivity between individuals

Question 16

Environmental effects

Temp sensitive alleles examples are

Answer 16

Himalayan rabbits
Siamese cats
Activating the gene at different temps

Question 17

Environmental effects via Nutrition

What are the examples

Answer 17

Lactose intolerance (expressivity differs)
PKU (expressivity differs)

Question 18

Pleiotropy

What causes it and what does the allele do

Answer 18

Single allele multiple phenotypes

PKU cause mental retardation, blue eyes, light skin colour

Question 19

Pleiotropy melanin in cats

What doe it cause

Answer 19

Lack of melanocytes (blance in ear) during embryo development
Results in white fur and deafness

Question 20

Environmental determination

Temperature dependent sex determination in crocodiles

Answer 20

Temp sensitive aromatase
Converts androgen to
Testosterone or oestrogen

Question 21

Sex determination

Haplo-diploidy

Answer 21

Bees

Question 22

Sex chromosome system

Answer 22

XX-XO protenor system grasshopper
XX-XY MAMMALS
ZZ-ZW birds

Question 23

What does the SRY gene code for mammals

Answer 23

Male sex

Question 24

Drosophila Humans Mouse if they were all XO

Answer 24

Sterile Female turners syndrome sterile Male y promote male development Functional female

Question 25

Birds sex determination | What are ZZ AND ZW called

Answer 25

Homogametic | Heterogametic

Question 26

Sex determination in plants | Plants can be either

Answer 26

Monoecious- hermaphrodite | Dioecious- male/ female flower on separate plants

Question 27

Male sex linkage | 2 possible genotypes

Answer 27

X+ Y Xm Y Inherited from mother Hemizygous

Question 28

Females 3 possible genotypes

Answer 28

X+X+ X+Xm XmXm Heterozygotes are carriers of recessive traits

Question 29

X linked dominant traits

Answer 29

Affected males (XBy) will produces all affected daughters, not affect sons 50% heterozygous affected females will pass in trait to the son not daughter Homozygous females pass on traits to all offspring

Question 30

Sex limited inheritance | Autos ones not XY

Answer 30

Autosomal gene | Allele cannot be expressed and individual is the wrong sex

Question 31

Sex influenced inheritance

Answer 31

Sex influences dominance relationship between autosomal alleles Pattern baldness dom in males reces F

Question 32

Pedigree analysis | 3 primary patterns of inheritance

Answer 32

``` Autosomal recessive Autosomal dominant Sex linked (X chromosomal) ```

Question 33

Autosomal recessive pedigree | What does it mean

Answer 33

If neither parent has it and child does it's recessive Not in the x or y means it's autosomal Can skip gens

Question 34

Eg of recessive autosomal

Answer 34

Albinism PKU Sickle cell anaemia Tay Sachs disease

Question 35

Dominant autosomal pedigree | What is it

Answer 35

Not in x or y | Trait always appears in successive gens

Question 36

Example of autosomal dominant

Answer 36

Huntingtons disease | Polydactly

Question 37

Sex linked pedigree and egs

Answer 37

Female carrier Male gets it Colour blindness Haemophilia

Question 38

Determined

Answer 38

Committed to specialised development | Self perpetuation

Question 39

Differentiated

Answer 39

Overt cell specialisation grossly apparent | Usually a cell becomes determined before differentiation

Question 40

Cell replacement: permanent cells

Answer 40

Eye lens and auditory hair cells 3H leucine pulse follows the passage of radioactive protein 3-4 new discs of photoreceptive membrane are formed per hour

Question 41

Simple duplication | What does this

Answer 41

Endothelial cells

Question 42

Undifferentiated stem cells can do what

Answer 42

Divide without limit | Either stem or differentiate

Question 43

Unipotent

Answer 43

Olfactory

Question 44

Oligopotent

Answer 44

Epithelial cells

Question 45

Pluripotent

Answer 45

Blood cells

Question 46

Totipotent

Answer 46

Embryo cells

Question 47

Pluripotent differentiation of blood cells what happens

Answer 47

2 progenitor steps to form everything apart from platelet and RBC Which require 3

Question 48

Things that affect pluripotent differentiation

Answer 48

Factors - colony stimulating RBC formed by low O2 In blood Receptor- cytokines Target cells- with receptors for CSF's