ch 14 - forms of inheritance

Question 1

mutation def

Answer 1

any change in the DNA

Question 2

autosomal dominant def

Answer 2

only takes 1 copy to have the trait

ex: huntingtons, hypercholesterolemia, breast cancer

Question 3

autosomal recessive def

Answer 3

need 2 copies of allele to express trait

ex: CF, CKU, taysachs, albinism

Question 4

x-linked dominant def

Answer 4

all daughters of affected male will have trait, all sons of a homozygous affected female will have trait

ex: fragile X

Question 5

x-linked recessive def

Answer 5

all sons of affected female and 1/2 sons of a carrier female will express the trait; all daughters of affected male will be carriers

ex: hemophilia, color blindness, DMD

Question 6

do mitochondria have double-stranded DNA? what is it called?

Answer 6

yes; mtDNA

Question 7

mitochondrial trait def

Answer 7

passes only from the mother because the sperm’s mitochondria is in the tail which disintegrates during fertilization

affected female passes to all children, affected males do not to any
ex: mitochondrial myopathy

Question 8

mtDNA (maternal inheritance) def

Answer 8

mother gives trait to all children, males won’t pass it on

Question 9

to determine pattern of inheritance in pedigree for sex-linked trait

Answer 9

if there are way more males than females affected

Question 10

if child is different from both parents-

Answer 10

label child homozygous recessive and parents heterozygous

Question 11

if child is shaded and parents are not-

Answer 11

pedigree is tracing autosomal recessive trait

Question 12

if parents are shaded and child is not-

Answer 12

pedigree is tracing autosomal dominant trait

Question 13

genetic anticipation def

Answer 13

onset of symptoms and severity increases with successive generations. due to genes where the number of triplets increase when passed to child (trinucleotide repeats)

ex: huntington’s disease, fragile X, myotonic dystrophy

Question 14

in genetic anticipation, the more repeats-

Answer 14

the earlier the onset and the more severe the disease

Question 15

which trinucleotide repeats in huntington’s?

Answer 15

CAG

Question 16

which trinucleotide repeats in fragile X?

Answer 16

CGG

Question 17

which trinucleotide repeats in myotonic dystrophy?

Answer 17

CTG

Question 18

what are 2 main types of mutations?

Answer 18

gene mutations and chromosome mutations

Question 19

gene mutation def

Answer 19

happens during DNA replication, due to point mutations or frameshift from an insertion or deletion affecting all the codons that come after the error

ex: cystic fibrosis, dwarfism, sickle cell anemia

Question 20

DNA replication def

Answer 20

a change to the original DNA sequence

Question 21

point mutations def

Answer 21

1 base change

Question 22

chromosome mutation def

Answer 22

happen during meiosis, changes the number or location of genes

ex: down syndrome, klinefelters syndrome, turners syndrome

Question 23

chromosomal errors def

Answer 23

deflects are due to errors in a large piece of the chromosome

Question 24

deletion def

Answer 24

large section of the chromosome is lost

Question 25

duplication def

Answer 25

broken piece attaches to the homolog

Question 26

inversion def

Answer 26

a broken section reattaches in reverse order (some harmless

Question 27

translocation

Answer 27

broken pieces swap positions on different chromosomes can cause trisomies, tumors, miscarriages, philidelphia chromosome (translocation of #9 and #22 leading to leukemia

Question 28

mutations of chromosomes:

Answer 28

deletion, duplication and deletion, inversion, reciprocal translation between 2 different chromosomes

Question 29

can some single gene mutations be due to more than one reason?

Answer 29

yes

ex: SCIDS

Question 30

nonfunctional protein

Answer 30

Nonsense mutations result in a polypeptide chain that is shorter and is non-functional.

Question 31

A nonsense mutation

Answer 31

results in the addition of an incorrect amino acid, but can still lead to a functional protein

Question 32

huntingtons disease

Answer 32

half the people in a Venezuelan village affected

a large pedigree was conducted of 10,000 people by Nancy Wexler; lead to the identification of the gene at the tip of chromosome 4

Question 33

transposons def

Answer 33

jumping genes - segment of RNA that can move from 1 chromosome location to another

ex: corn bacteria retroviruses

Question 34

human genome project def

Answer 34

mapped out the genes on the 24 chromosomes to cure sound 4000 diseases by gene therapy- a diagnosis could alter the patients lifestyle for multifactorial traits

ex: hypercholestromia, autosomal dominant diseases

Question 35

Germaine gene therapy risks

Answer 35

I/ No consent of future generations

II. Possible fatal flaw

III. Eugenics

Question 36

the only disease gene therapy has cured

Answer 36

SCIDS

Question 37

the lac operon gene operon

Answer 37

e coli bacteria synthesizes lactase to break down lactose, which is only made in the presence of lactose. if theres no lactose, the gene is repressed. it lives on whatever the host drinks then- so if u drink milk then that’s what it uses