Mendel's law

Question 1

what are mendel’s 2 laws

Answer 1

1) law of segregation 2) law of independant assortement

Question 2

what are the names of generations

Answer 2

1) parental
2) first filial
2) second filial

Question 3

what is a monohybrid cross

Answer 3

cross fertilizitation between 2 monohybrid organisms (monohybrid = heterozygous for 1 sepecific trait)

cross between 2 individuels who are heterozygous at 1 locus, only compares 1 trait

Question 4

how to perform a test cross

Answer 4

• cross mystery parent with homozygous recessive parent, because phenotype does not always reveal genotype (can be heterozygous or homozygous dominant)
• if it is an all dominant offspring, YY
• if mixed , Yy

Question 5

what is a dihybrid cross

Answer 5

-cross-fertilization between 2 dyhibrid organisms (2 organisms that are heterozygous for 2 specific traits)

Question 6

what is the rule of multiplication

Answer 6

probability for more then 2 events to occur together is calclulated by multiplying the chances each event occurs alone

Question 7

what is polygentic inheritence

Answer 7

a signle phenotypic trait affected by multiple genes

Question 8

what is pleiotropy

Answer 8

a single gene that has an effect on multiple genetic traits

Question 9

what is the law of segregation

Answer 9

2 alleles of same gene will end of in different gametes after meiosis

Question 10

what is the law of independant assortement

Answer 10

alleles of 2 different genes get sorted into gametes indep. of each other (homologous chromosomes randomly line up in metaphase 1 and 2)

Question 11

are sex chromosomes truly homologous?

Answer 11

No, but they do pair up during meiosis and behave like homologous (posseses small regions where they are homologous)

Question 12

what are some sex linked characteristics

Answer 12

• hemophilia (lack of blood coagulation)
• color blindness (

Question 13

what is dosage compensation (x inactivation)

Answer 13

• since woman have 2 xx chromosomes, dosage compensation works to make the doses equal
• inactivation of 1 or part of the x chromosome

Question 14

what is a barr body

Answer 14

dense, metabolically inactive x chromosome, to avoid over-expression of the x genes in females

Question 15

what is polyploidy

Answer 15

presence of multiple sets of chromosomes (more then n , ie, more then diploid) , does not cause abnormalities (3n, 4n), more then 1 pair of homologous chromosomes

Question 16

what is Aneuploidy

Answer 16

abnormalities caused by too many or too little chromosomes

Question 16

what is nondisjunction

Answer 16

• results in aneuploidy
• abnormal number of chromosomes
• can occur in autosomes and sex chromosomes

Question 17

what is disomy

Answer 17

normal

Question 18

what is trisomy

Answer 18

extra chromosomes (3 of one kind)

Question 19

what is monosomy

Answer 19

lack one member of a pair of chromosomes

Question 20

what is Turner’s syndrome in woman

Answer 20

• XO (lack of Y)
• girls lack normal ovaries
• may have male characteristics (lack of breasts)

Question 21

what is Klinefelter syndrome

Answer 21

• YXX
• male, possess y chromosome
• may have breasts and other male charateristics
• can be alleviated with long term treatment

Question 22

what are the types of abnormal chromosome structures

Answer 22

• Deletion
• Duplication
• Inversion
• reciprocal translocation

Question 23

what is the relation between genes and the environment

Answer 23

• the genes set the limits, the environment molds the phenotyp, within gene’s limits

Question 24

what is epistasis

Answer 24

certain alleles of one lucus can mask expression of alleles of different locus

Question 25

what is incomplete dominance

Answer 25

heterozygous, mix of both traits/alleles (red + white = pink)

Question 26

can you survive without X chromosome

Answer 26

No

Question 26

what is codominance

Answer 26

heterozygous, both traits expressed

Question 27

what does it mean if YYX

Answer 27

normal sexual dev, taller then normal