Genetics Intro Flashcards
1
Q
Genotype
A
- type of genes you have
2
Q
Phenotype
A
- result of the expression of those genes
3
Q
Blood Types
A
- Type A- could have 2 copies of genes that code for A, AA or AO (A dominant)
- Type B- BB or BO
- Type AB- AB only, expresses both A and B
- Type O- OO (homogenous recessive)
4
Q
blood markers
A
- there are markers on red blood cells for A and B
- no markers for O
- for AB, codominant, have both markers
5
Q
RH Factor
A
- negative and positive in blood type
- Codes for an enzyme that adds to another marker on cells
- If you have gene for enzyme that has RH factor–> then considered RH positive
- makes a difference in blood transfusions
- 2 alleles (+ and -)
6
Q
Rhogam
A
- substance that is injected into mothers before birth if they have -RH factor and baby is +RH
- during birth, antibodies can cross barrier (cells will not)–> this attacks blood cells of baby
- Rhogam blocks antibodies
- if antibodies are not blocked–> Creates RH disease–> presence of immature red blood cells in fetus (eyrthroblastosis- still have a nucleus), can cause baby to die
7
Q
Sickle cell anemia
A
- Change in amino acid makes a big difference in protein
- Glutamic acid (charged) is switched to valine (not charged) in position 6 from N terminus
- Causes hemoglobin to stick together in a funny way
- causes sickle cell shape–> sticky, get stuck in capillaries, cause pain in joints/organs
- Heterozygous- don’t have symptoms, but if two have child who is homozygous
- 2b = normal
- 1b 1s = asymptomatic, have the trait, resist malaria
- 2s = have the disease
positive selection–> African American population has a higher concentration of sickle cell allele (resist malaria)
8
Q
hydroxy urea
A
- drug helps alleviate sickle cell disease
- During embryonic development, people can express fetal hemoglobin gene (F gene)- think it has a higher oxygen affinity (works better in fetal condition)
- this gene is turned off in adult and only hemoglobin A is expressed
- IN SICKLE CELL- patients have defective hemoglobin S that causes sickle cell–> drug can induce hemoglobin F (but there are side effects)
9
Q
Karyotype
A
- chromosomal analysis
- Can digitally arrange all chromosomes
- See if you have right numbers and sizes
10
Q
Genetics
A
- Involved in passing genetic information from one generation to the next
11
Q
heterochromia
A
- 2 different colored eyes
12
Q
the homunculus
A
- People thought there were tiny babies in sperm
13
Q
Plant parts
A
- flowers with both male and female parts
- pistil (middle part)- have female parts, egg is in the bottom of it
- stamen- male part
- Pollen is distributed to other things (animals)
- sexual reproduction- When pollen flies through air and into stigma–> goes down to egg
14
Q
Mendel
A
- Controlled which flower was fertilized by which stamen (pollen)
- Studied 7 different traits: flower color, seed color, seed shape, pod color, pod shape, flower position, plant height
15
Q
genetic protocol (Mendel)
A
- Parent 1 and parent 2
- F1= Cross parents and get offspring (1st filial generation)
- Self cross F1- mate w/ self, F2 = 2nd filial generation
- in F1, get dominant and same phenotype
- when you self cross in F2 ratio of traits that are dominant to recessive is 3:1
16
Q
carrier
A
- individuals that are heterozygous and showing dominant phenotype
- also have the “trait” for something
17
Q
autosomes
A
- regular chromosomes (not sex chromosomes)
18
Q
albinism
A
- autosomal recessive
- don’t make normal pigment
- eye red, no pigment so see blood color
- sometimes have vision problems
- Leucistic- have pigment in eyes, lack pigment in other areas
19
Q
Huntington’s Disease
A
- dominant neurodegenerative disease
- age 44, start experiencing shaking, chorea= a dance
- Huntington’s is rare, and rate is not increasing
20
Q
Frequency of a dominant allele
A
- has nothing to do with it being dominant
- Depends on whether it has been selected for or not
- ex. Huntington’s is dominant but rare
21
Q
test cross
A
- used to reveal the unknown genotype of an individual
- ex. if you don’t know if smooth is heterozygous or homozygous dominant
- cross with homozygous recessive
- -> if all dominant offspring–> know was homozygous dominant
- -> if 1:1 ratio–> know was heterozygous dominant
22
Q
dihybrid cross
A
- Each of these genes is sorting independently–> not affecting distribution of the other
- ratio is 9:3:3:1
23
Q
dihybrid test cross
A
- cross with homozygous recessive for both genes
- get ratio 1:1:1:1
24
Q
Mendel’s laws
A
- Mendel’s 1st law = law of segregation- recessive gene exists separately from the dominant gene and reexpress in later generations
- Mendel’s 2nd law = law of independent assortment- 2 different genes distribute themselves independently (9:3:3:1 ratio)
25
Q
Phenotypes/genotypes expected in offspring from a cross showing independent assortment
A
n = number of gene pairs being followed
Monohybrid cross:
2^n = 2^1 = 2
Dihybrid cross:
Phenotypes
2^n = 2^2 = 4
Genotypes
3^n = 3^2 = 9
Trihybrid cross:
Phenotypes
2^n = 2^3 = 8
3^n = 3^3 = 27
26
Q
ratios to memorize
A
- Monohybrid cross 3:1
- Monohybrid test cross 1:1
- Dihybrid cross 9:3:3:1
- Dihybrid test cross 1:1:1:1
