Biology 11

Front 1

Concept of Blending Inheritance

Back 1

Parents of contrasting appearance produce offspring of intermediate appearance.

Front 2

Particulate theory of Inheritance

Back 2

Inheritance involves reshuffling of genes from generation to generation.

Front 3

Why use the garden pea (5)

Back 3

1. Easy to cultivate

2. Short generation

3. Normally self-pollinating, can be crossed by hand

4. True-breeding varieties available

5. Simple, objective traits

Front 4

Homozygous

Back 4

True-breeding

Front 5

Monohybrid Cross

Back 5

Varieties differing in only one trait

Front 6

Law of Segregation

Back 6

1. Each individual has a pair of factors for each trait.

2. The alleles separate during gamete formation.

3. Gametes contain one factor.

4. Fertilisation give offspring two factors.

Front 7

Gene locus

Back 7

Location of allele on chromosome.

Front 8

Heterozygous

Back 8

Different Alleles

Front 9

Genotype

Back 9

Two alleles an individual has fo one trait.

Front 10

Phenotype

Back 10

Physical appearance

Front 11

Allele

Back 11

Gene for specific trait

Front 12

Homologous

Back 12

Pair of chromosomes with same trait at same locus.

Front 13

Law of Independant Assortment

Back 13

Pair of factors for one trait separate independantly of factors for other traits

All possible combinations can occur.

Front 14

Dihybrid Cross

Back 14

True-breeding plant differing in one trait

Front 15

Mendel tracked a trait...

Back 15

Start with true-breeding differing in two traits.\F1 shows both dominant characteristics.

F1 self-pollinates.

Observe.

Front 16

Testcross

Back 16

Determines genotype of individual with dominant phenotype.

Front 17

Genetic Disorders

Back 17

Medical conditions caused by alleles inherited from parents.

Front 18

Autosome

Back 18

Any chromosome other than sex chromosomes X & Y

Front 19

Autosomal Dominant

Back 19

Aa yes

AA yes

aa no

Front 20

Autosomal Recessive

Back 20

AA no

Aa no

aa yes

Front 21

Methemoglobinema

Back 21

AUTOSOMAL RECESSIVE

Chromosome 22

Accumulates methemoglobin in blood, hands look blue

Front 22

Cystic Fibrosis

Back 22

AUTOSOMAL RECESSIVE

Chromosome 7

Mucus in bronchial tubes and pancreatic ducts. Affected Ca+ channels

Front 23

Phenylketonuria

Back 23

AUTOSOMAL RECESSIVE

Affects nervous system development

Lacks enzyme for normal metabolism of phenylalanine - diet low in that enzyme.

Front 24

Phenylketonuria diet low in

Back 24

Milk

Dairy

Fish

Eggs

Chicken

Eggs

Beans

Nuts

Front 25

Osteogenesis Imperfecta

Back 25

AUTOSOMAL DOMINANT

Weak, brittle bones

Mutation in genes required for synthesis of type 1 collagen

Front 26

Huntington Disease

Back 26

AUTOSOMAL DOMINANT

Chromosome 4

Mutated gene coding for protein huntingtin

Progressive degeneration of brain cells causing large clumps inside neurons

Problems appear in middle age normally

Front 27

Hereditary Spherocytosis

Back 27

AUTOSOMAL DOMINANT

Minowski-Chauffard Syndrome

Chromosome 8, ankyrin-1 gene

Red blood cells spherical, fragile, burst

Front 28

Co-dominance

Back 28

More than one allele is fully expressed, eg ABO blood groups.

Front 29

Incomplete Dominance

Back 29

Heterozygote has phenotype intermediate between that of either homozygote. Eg red, white, pink flowers.

Front 30

Familial Hypercholesterolemia

Back 30

INCOMPLETE DOMINANCE

Homozygotes develop fatty deposits in skin & tendons; childhood heart attacks.

Heterozygotes may get heart attacks in early adulthood.

Front 31

Incomplete Penetrance

Back 31

The dominant allele may not always lead to the dominant phenotype in a heterozygote. Exhibit varying degrees of penetrance.

Front 32

Polydactyly

Back 32

INCOMPLETE PENETRANCE

Extra digits on hands or feet or both. Not all individuals who inherit the dominant polydactyly will exhibit the trait.

Front 33

Pleiotropy

Back 33

A single mutant gene affects two or more distinct and seemingly unrelated traits.

Front 34

Marfan Syndrome

Back 34

PLEIOTROPY

Chromosome 15

Abnormal connective tissue (disproportionate hands, legs, feet etc., weak aorta, poor eyesight.

Front 35

Pleiotropy Examples

Back 35

Porphyria

Sickle Cell Aneamia

Front 36

Polygenic Inheritance

Back 36

A trait is governed by two or more genes having different alleles. Additive effects.

Front 37

Polygenic Inheritance examples

Back 37

Skin colour, height, hair colour

Front 38

X-linked Inheritance

Back 38

Nothing to do with gender.

X chromosome carries genes. Y chromosome ONLY codes for being male.

Front 39

X linked Inheritance Discoveries

Back 39

Colubia University in 1900s, headed by Thomas Hunt Morgan on fruit flies (easy, inexpensive, similar sex chromosome pattern as humans)

Front 40

Colour Blindness

Back 40

X LINKED RECESSIVE

Allele for blue-sensitive is autosomal.

Green and red-sensitive cells are X linked.

Front 41

Menkes Syndrome

Back 41

X LINKED RECESSIVE

Defective allele on X.

Disrupts movement of Cu in and out of cell.

Kinky hair, poor muscle tone, siezures, low body temp.

Front 42

Muscular Dystrophy

Back 42

X LINKED RECESSIVE

Wasting away of muscle.

Caused by absence of protein dystrophin.

Front 43

Adrenoleukodystrophy

Back 43

X LINKED RECESSIVE

Failure of carrier protein to move an enzyme or long fatty acid into peroxisomes.

Front 44

Haemophilia

Back 44

X LINKED RECESSIVE

Absence or minimal clotting factor VIII or IX.

Affected person's blood doesn't clot or clots slowly.