Chapter 14 Flashcards

You may prefer our related Brainscape-certified flashcards:
1
Q

what is the “blending” hypothesis?

A

the idea that genetic material from the two parents blends together and can never go back to what it was before

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

what is the “particulate” hypothesis?

A

the idea that parents pass on discrete heritable unites (genes)
-explains reappearance of traits after several generations

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

what did mendel discover?

A

the basic principles of heredity by breeding garden peas in carefully planned experiments

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

characters

A

distinct heritable features (such as flower color)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

traits

A

character variants (such as purple or white)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

true breeding

A

an organism that always passes down certain phenotypic traits (i.e. physically expressed traits) to its offspring

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

hybridization

A

two contrasting, true breeding varieties

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

P generation

A

the true breeding parents

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

F1 generation

A

hybrid offspring of the P generation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

F2 generation

A

when F1 individuals self pollinate or cross pollinate with other F1 hybrids

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

what is the law of segregation?

A

stating that during the production of gametes the two copies of each hereditary factor segregate so that offspring acquire one factor from each parent.
-happens during anaphase 1 of meiosis 1

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

what is the ratio that mendel came up with for the offspring of the f1 generation

A

3:1

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

alternative versions of genes account for ______ in inherited characters

A

variations

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

alleles

A

alternative versions of a gene

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

each gene resides at a specific ____ on a specific chromosome

A

locus

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

for each character, an organism inherits ___ alleles

A

two (one from each parent)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

if the two alleles at a locus differ, then the _____ allele determines the organism’s appearance, and the ______ allele has no noticeable effect on appearance.

A
  • dominant

- recessive

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

homozygous

A

An organism with two identical alleles for a character

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

heterozygous

A

An organism that has two different alleles for a gene

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

true or false: heterozygous is true breeding

A

false

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

phenotype

A

physical appearance

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

genotype

A

genetic makeup

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

testcross

A

breeding the mystery individual with a homozygous recessive individual

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

monohybrids

A

individuals that are heterozygous for one character

25
Q

monohybrid cross

A

cross between monohybrids

26
Q

dihybrids

A

heterozygous for two characters

27
Q

dihybrid cross

A

a cross between two dihybrids….can determine whether 2 characters are transmitted to offspring as a package or independently

28
Q

law of independent assortment

A

each pair of alleles segregates independently of each other pair of alleles during gamete formation
–Strictly speaking, this law applies only to genes on different, nonhomologous chromosomes or those far apart on the same chromosome
—Genes located near each other on the same chromosome tend to be inherited together
EXAMPLE:
Hh hH
J j or J j

29
Q

Multiplication rule

A

the probability that two or more independent events will occur together is the product of their individual probabilities

30
Q

Addition rule

A

states that the probability that any one of two or more exclusive events will occur is calculated by adding together their individual probabilities (uses words either/or)

31
Q

complete dominance

A

occurs when phenotypes of the heterozygote and dominant homozygote are
identical….the dominant is the only one apparent in physical terms

32
Q

incomplete dominance

A

the phenotype of F1 hybrids is somewhere between the phenotypes of
the two parental varieties….two dominant alleles are mixed together to create a certain phenotype such as straight and curly hair = wavy hair (something like this)

33
Q

what is codominance

A

two dominant alleles affect the phenotype in separate distinguished ways….both dominant alleles show up such as when you have alleles for both straight and curly hair and they both show up on your hair, some strands straight and some curly (something like this)

34
Q

remember !!!

A

A dominant allele does not subdue a recessive allele

35
Q

Tay-Sachs disease

  • what does it look like @ the organismal level
  • biochemical level
  • molecular level
A

organismal level: asymptomatic-shows no symptoms because normal allele is dominant so covers for tay sachs

biochem: normal allele makes correct protein (an enzyme) so accumulation does not occur in brain
molecular: one normal allele on one chromosome and one tay sach allele on the other…normal allele is dominant

36
Q

what are the three alleles for blood types

A

A, B, and O

37
Q

what does blood type A look like

A

a red blood cell that has a tag (a carbohydrate) that represents that it is A blood type

38
Q

what does blood type B look like?

A

a red blood cell that has a tag (a carb) that represents that it is B blood type

39
Q

what does AB blood type look like?

A

a red blood cell that has two tags, one that represents A and the other that represents B

40
Q

what does the O blood type look like?

A

it has no tags…just the red blood cell

41
Q

pleiotropy

A

multiple phenotypic effects… when one gene influences two or more seemingly unrelated phenotypic traits….. a mutation in a pleiotropic gene may have an effect on some or all traits simultaneously.

42
Q

true or false: some traits may be determined by two or more genes

A

true

43
Q

epistasis

what ratio does it have?

A

a gene at one locus alters the phenotypic expression of a gene at a second
locus
-example: the golden retrievers that should be black or brown but have a gene that prevents this
9:3:4

44
Q

quantitative characters

A

characters that vary in the population along a continuum

45
Q

polygenic inheritance

A

an additive effect of 2 or more genes on a single phenotype

-so two or more genes affect the phenotype of someone

46
Q

norm of reaction

A

the phenotypic range of a genotype influenced by the environment
ex)hydrangea flowers of the same genotype range from blue-violet to pink depending on soil

47
Q

multifactorial

A

when genetic and environmental factors collectively influence phenotype

48
Q

pedigree

A

a family tree that describes the interrelationships of parents and children across generations

49
Q

carriers

A

heterozygous individuals who carry the recessive allele but are phenotypically normal

50
Q

albinism

A

a recessive condition characterized by a lack of pigmentation in skin and hair

51
Q

consanguineous mating

-what is it and why is it bad

A

incest

-it is bad because it increases the change of mating between two carriers of the same bad and rare allele

52
Q

cystic fibrosis

A

cystic fibrosis allele results in defective or absent chloride transport channels in plasma membranes leading to a buildup of chloride ions outside the cell

  • -symptoms include mucus buildup in some internal organs and abnormal absorption of nutrients in the small intestine.
  • —serious breathing problems
53
Q

sickle cell disease

A
  • caused by the substitution of ONE amino acid in the hemoglobin protein the the red blood cells
  • -in homozygous individuals all hemoglobin is abnormal (sickle cell)
  • —symptoms include physical weakness, pain, organ damage, bursting of cells
  • people heterozygous for this are usually healthy but may have some symptoms
54
Q

true or false: some human disorders are caused by dominant alleles

A

true

55
Q

what is achondroplasia

A

a form of dwarfism caused by rare dominant allele….NEVER HOMOZYGOUS FOR DOMINANT ALLELE BECAUSE THAT IS LETHAL

56
Q

Huntington’s disease

A
  • a degenerative disease of the nervous system
  • -no phenotypic effects until the individual is about 35 to 40 years of age
  • irreversible and fatal
  • don’t know until later in life which is why people pass on the allele for this disease, because they don’t know they have it until later on in life after having kids
57
Q

amniocentesis

A

the liquid that bathes the fetus is removed and tested for any disease the fetus might have when born….look at the karyotype

58
Q

chorionic villus sampling (CVS)

A

a sample of the placenta is removed and tested ….scrape DNA material from placenta (an organ you grow when pregnant)