Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

CU: Genetics > Chapter 2: Heredity > Flashcards

Chapter 2: Heredity Flashcards

You may prefer our related Brainscape-certified flashcards:
Biology 101 flashcards
1
Q

What about God’s authority in heredity?

A
  • It shows that God is detailed and knows everything (heredity has detailed interactions at cellular level)
  • As Stewards we must manage well the information that has been given to us
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Who was Gregor Mendel?

A
  • The Man who discovered the basics of Genetics
  • Main studies in 1856-1873
  • first scientist to combine data in a collection, analyze and provide an explanation theory to understand heredity
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What are genes? What do they do?

A

The basic unit of heredity, a section on the DNA code of a chromosome for a protein that is often associated with a trait
Do: underly formation of heritable traits, some from one gene, some from multiple

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

What is heredity?

A

how genes get transmitted from parents to offspring

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

What is the background of Mendel’s work? (first techniques, questions, theories)

A
  • Artificial (human) selection is the first applied genetic technique
  • Results were unpredictable
  • Abbot Napp (1837): what is inherited? how? what is the role of chance? (Napp presided over Mendel’s monastery at time of experiments)
  • Misleading theories: Homunculus: only one parents contributes or Blended inheritance: traits mixed and changed in offspring
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Artificial selection

A
  • to control mating by choosing the next generation’s parents
  • Domestication of plants/animals goes with the advancement of civilization
  • Adam and children undoubtedly practiced this because they were intelligent
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What did Mendel’s laws do and what were his keys to success?

A

Laws: allow predictions for when traits appear, disappear, and reappear
Keys: - pure-breeding line of peas that bred by cross-fertilization and selfing, grew quickly, and constant traits
- Inheritance of alternative forms of traits were antagonistic
- He was brilliant with carefully planned and carried out, crossed, and analyze

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

What were the antagonistic pairs of traits Mendel studies?

A

(7) Seed color, seed shape, flower color, flower position, pod color, pod shape, and stem length

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

What does the monohybrid crosses reveal?

A

The unit of inheritance and the law of segregation
- Cross pure-breeding lines differs in one trait
- Both plant parents have two copied of inheritance unit with two forms, if it is in the F1 it is dominant if it is not it is recessive

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

What is seen in the phenotype of F1 and F2?

A

F1: progeny only one of parental traits
F2: both parental traits reappear in 3:1 ratio
**Disproves both prior theories
- results form reciprocal crosses produced similar results

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

What are alleles?

A

Different forms of genes

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

What is the difference between phenotype and genotype?

A

Observable characteristics and a pair of alleles

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

What is the difference between homozygote and heterozygote?

A

Homo: same alleles
Hetero: different alleles

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

What is the law of segregation?

A

two alleles separate during gamete formation and two gametes unite at fertilization
- F1: two kinds of gametes 1:1
- F2 3:1 ratio, 1/4 dom, 1/2 hybrid, 1/4 reces
- Verified by further croses
F2 selfed to F3 gets alll green from pure breeding, 1/3 yellow from pure breeding, 2/3 yellow from hybrid

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

What is the product rule?

A

Probability of two independent events occurring together is the product of the individual probabilities
Yy, Yy, get YY is 1/4

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

What is the sum rule?

A

probability of either of two mutually exclusive events occurring is the sum of individual probabilities
Yy x Yy get Uu is 1/4 + 1/4 = 1/2

17
Q

What do test crosses do?

A

Reveal unknown genotype: dominant homo or hetero?

18
Q

What genotypes and phenotypes will a cross of two heterozygous parents create?

A

3:1 phenotype
3 genotypes
- self-breeding has a push toward homozygosity

19
Q

What is independent assortment? What reveals it?

A
  • During gamete formation different pairs of alleles segregate independently
  • revealed by dihybrid cross
  • 9:3:3:1 phenotype
  • 4 gametes, 4 phenotypic classes, 2 parental type and two recombinant types (combination of parents)
20
Q

What are branching line diagrams?

A

Used for more complex gene crosses
- progeny phenotypes for each gene are show in different columns
- Gene 1: note fraction, Gene 2: note fractions, use product rule to get final fraction

21
Q

How do you predict offspring in complicated crosses?

A
  • # different gametes = 2^n
  • n = number of different traits
    (AaBbCcDd) = 2^4 = 16
    Multiply gamete numbers to determine number of total genotypes
    AaBbCcDd x AaBbCcDd = 2^4 x 2^4 = 256
  • Calculate probability of each gene then use product rule
    AaBbCcDd x AaBbCcDd probablitity = AAbbCcDd?
    Aa x Aa = AA 1/4
    Bb x Bb = bb 1/4
    Cc x Cc = Cc 1/2
    Dd x Dd = Dd 1/2
    1/4 x 1/4 x 1/2 x 1/2 = 1/64
22
Q

How did the science of genetics begin?

A
  • rediscovering Mendel’s work: early-mid 1800s, published 1860s
  • Darwin published right before Mendel
  • Late 1800s three labs similar conclusions to Mendel ~1905 take advantage to increase food production
  • labs lead by botanists from Germany, Denmark (Dutch), Austria
23
Q

What is the molecular explanation for the pea appearances?

A
  • R allele: encodes enzyme that makes Starch branch (Sbe 1)
  • r allele not make Sbe1 so has sucrose and unbranched starch causing shrinking and wrinkling
  • Y allele encodes enzyme (Sgr) breaks down chlorophyll
  • y allele not make Sgr so Chlorophyll not broken down (stay green)
24
Q

What are the two general molecular principles?

A
  • Specific gene determines specific enzyme whose activity may affect phenotype
  • Dominant normally functioning protein
  • Recessive alleles not encode functioning protein (from mutation or God-built in flexibility)
25
Q

What about Mendelian inheritance in humans?

A
  • many inheritable traits care caused by interactions of many genes do not show Mendelian inheritance patterns
  • single-gene traits in humans are also tricky when trying to determine inheritance: long generation time, small number progeny, no controlled mating, and no pure-breeding lines
  • some most common single-gene trait diseases caused by recessive alleles in humans
  • Use pedigrees
26
Q

What are the symbols in pedigrees?

A

Square - male, circle - female, diamond (unknown/unspecified)
shading: condition/disease
line through: deceased
numbers: progeny
double line: consanguineous mating (cousins)

27
Q

What about cystic fibrosis and genetics?

A
  • recessive allele, encoding abnormal CFTR protein that allows for passage of chloride ions across the membrane (absent in lung affecting breathing)
28
Q

What about recessive traits in pedigrees?

A
  1. Can have unaffected parents (heterozygous, “carriers)
  2. If both parents affected then all children should be affected
  3. Rare recessive traits: horizontal pattern of inheritance
  4. Extremely common recessive traits may show vertical pattern of inheritance
29
Q

Dominant traits in pedigrees

A
  1. Affected children have at lease one affected parent
  2. Vertical pattern of inheritance
  3. Un affected children possible if both parents heterozygous

CU: Genetics (7 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions