Ap Biology Chapter 14 & 15

Front 1

Blending

Back 1

idea that genetics of 2 parents mixes (like paint in a bucket)

Front 2

Particulate

Back 2

idea that 2 parents pass on distinct units of inheritance that retain their separate identities in offspring

Front 3

Gregor Mendel

Back 3

-monk
-studied botany and math before he decided he wanted a simple life and not a "real world" job

Front 4

the garden pea plant (Why is it good for genetic testing?)

Back 4

-many varieties
-self pollinating but can be cross-pollinates
-true breeding
-reproduce quickly

Front 5

pollination

Back 5

transfer of pollen from the stamen to the pistil

Front 6

self-pollination

Back 6

fertilization occurs w/in a single plant

Front 7

cross pollination

Back 7

transferring pollen from one strain of pure plant to another strain that is pure for the contrasting trait

Front 8

Mendel's Experiement

Back 8

P Generation
-true breeding
-"parent generation"
F1 Generation
-offspring resulting from P generation
-"first filial generation"
-hybrids
F2 Generation
-offspring from F1
-"second filial generation

Front 9

Mendel's Conclusion

Back 9

2 fundamental principles of heredity

Front 10

Law of Independent Assortment

Back 10

each allele is independent from the other during meiosis

Front 11

Law of Segregation

Back 11

the 2 alleles for a character separate randomly during gamete production
-anaphase 1

Front 12

Mendel's F2 Cross Results

Back 12

dominant - recessive ratio of 3:1
-3 purple, 1 white

Front 13

How did Mendel explain the constant pattern?

Back 13

1. alternate forms of genes (alleles) account for variations of inherited characteristics
2. organisms inherit 2 alleles - one from each parent
3. if 2 alleles are different, then one is expressed (dominant)
4. the 2 alleles for a character separate during gamete production

Front 14

test cross

Back 14

-punnett square used to determine probable outcome
-not always spot on but if there is a big difference = mutation of something else is wrong

Front 15

pleitropy

Back 15

one gene affects an organism in multiple ways

Front 16

Genetics of Sickle cell Anemia

Back 16

two alleles
1. Hb^a : normal
2. Hb^s : sickle cell

Front 17

Pleiotrophic affects of two sickle cell alleles

Back 17

-at low O2 levels, blood cells with only Hb^s hemoglobin "sickle"
-causes blood cells to stick together
-impedes oxygen delivery
-over time, it causes damage throughout body

Front 18

epistasis

Back 18

multiple genes affect 1 phenotype

Front 19

albinism

Back 19

phenotype produced when pathway for melanin is completely blocked

Front 20

tyrosinase

Back 20

-An enzyme in the melanin synthesizing pathway
-Without an active tyrosinase melanin production is halted

Front 21

polygenic inheritance

Back 21

many genes plus environmental factors affect phenotype
-the greater number of genes and environmental factors that affect a trait, the more continuous the variation in versions of that trait
-examples include: height, weight, eye and skin color
-

Front 22

Genetic disorders

Back 22

Inherited conditions that cause mild to severe medical problems

Front 23

Why don't genetic disorders disappear?

Back 23

-mutation introduces new rare alleles
-in heterozygotes harmful allele is masked so it can still be passed on to offspring
-late onset: there already old enough to have had children by the time the disease is present
-heterozygous carrier
-beneficial

Front 24

Huntington's disease

Back 24

-Autosomal dominant allele
-Causes involuntary movements, nervous system deterioration, death
-Symptoms don't usually show up until person is past age of 30
-People often passed the allowing before they know they have it

Front 25

Multi-factorial disorders

Back 25

Many people are susceptible to diseases that have a multi-factorial basis
-A genetic component plus a significant environmental influence
Heart disease, diabetes, cancer, alcoholism, manic-depressive disorder, schizophrenia

Front 26

Phenotypic treatments

Back 26

Symptoms of many genetic disorders can be minimized or suppressed by:
dietary controls, adjustments to environmental conditions, and surgeries or hormonal treatments

Front 27

Homologous chromosomes

Back 27

-Homologous autosomes identical in length, size, shape, and gene sequence
-Sex chromosomes are nonidentical but still homologous
-Homologous chromosomes Interact (crossing over), then segregate from one another during meiosis

Front 28

Thomas Hunt Morgan

Back 28

First to associate the specific gene with a specific chromosome
-He selected drosophila melanogaster because they are prolific breeders, have only four chromosomes, and have many variants

Front 29

Linked groups of genes

Back 29

Linked genes tend to be inherited together because they're located close together on the same chromosome and I passed along other unit
-Close together equals less chance they will separate during crossover

Front 30

Full linkage

Back 30

No crossing over
Very close to centromere

Front 31

Incomplete linkage

Back 31

Crossing over

Front 32

Crossover frequency

Back 32

Morgan's student predicted that the further apart two genes are the higher the probability that a crossover will occur and therefore the higher the recombination frequency

Front 33

The Y chromosome

Back 33

You were than two dozen genes identified
One is the master gene for male sex determination (SRY gene)
-SRY present = tester
-SRY absent = ovaries

Front 34

the x chromosome

Back 34

carries more than 2300 genes
most genes deal with non-sexual traits
-genes on x chromosome can be expressed in both males and females

Front 35

Deletion

Back 35

Loss of some segment of a chromosome
Most are lethal or cause a serious disorder

Front 36

Duplication

Back 36

Gene sequence that is repeated several to hundreds of times
Duplications a car normal chromosomes
May have adapted advantage
Useful mutations may occur and copy

Front 37

Inversion

Back 37

A linear stretch of DNA is reversed

Front 38

Translocation

Back 38

A piece of one chromosome becomes attached to another nonhomologous chromosome

Front 39

Aneuploidy

Back 39

Individuals have an abnormal number of chromosomes
Trisomy: 2n +1
monosomy: 2n -1
Major cause of human reproductive failure
Most human miscarriages are aneuploids

Front 40

Polyploidy

Back 40

Individuals have three or more of each type of chromosome
Common in flowering plants
Lethal for humans
99% die before birth or newborns die soon after