mendelian genetics extended

Question 1

what is the first law of segregation (Mendel’s law)

Answer 1

Genes segregate at meiosis so that
each gamete contains only one of the
two possessed by the parent

Question 2

dihybrid cross

Answer 2

9:3:3:1

Question 3

what is the product rule?

Answer 3

independent events (whats happening at one doesn’t influence others)

Question 4

what is the second law of segregation (Mendel’s law)

Answer 4

Alleles of different genes assort
independently during gamete formation

Question 5

what is polymorphic?

Answer 5

a lot of different alleles for one gene (each individual can only have 2 alleles, one on each
homologous chromosome)

Question 6

what is co-dominance?

Answer 6

Where both phenotypes exist side by side within the organism

Question 7

what are polygenic traits?

Answer 7

Phenotype controlled by many genes that have
an additive effect

Question 8

what is the additive effect?

Answer 8

all the genes of the polygenic trait contributing to some way ( eg skin,height,IQ )

Question 9

what is the product rule?

Answer 9

independent events (what’s happening at one doesn’t influence others)

Question 10

what is the polygenic traits?

Answer 10

Phenotype controlled by many genes that have
an additive effect

Question 11

what is the additive effect?

Answer 11

Multiple genes are contributing one way or another – but their effects are added together to create a phenotype

Question 12

what plays a huge part in phenotypes?

Answer 12

environment plays a huge part in the phenotypes and genetic makeup

Question 13

what is the monohybrid ratio?

Answer 13

3:1

Question 14

how to find out the probability of getting a ssyy offspring from a SsYy x SsYy cross easier way?

Answer 14

break it down gene by gene

Question 15

what is the genotype?

Answer 15

combination of alleles

Question 16

why must we multiply each parent’s probability when finding out the total probability of that genome?

Answer 16

we must multiply the probability because the events are independent of each other since whatever happened in parent 1’s sperm had no influence in parent 2’s eggs

Question 17

what is the product rule?

Answer 17

when two events are independent we multiply them together

Question 18

what would happen if both parents could give out each of the resultant gene?

Answer 18

• find the probability of each possibility
• plus both of the outcomes
• final probability of getting that gene

Question 19

what is the sum rule?

Answer 19

mutually exclusive events are (a or b) and you add them together

Question 20

what’s the probability of BB?

Answer 20

1 because both ways you get one B

Question 21

how do new alleles arise?

Answer 21

through mutation

Question 22

what is phenotype?

Answer 22

its what you can see

Question 23

what is typical of polygenic trait?

Answer 23

• normal distribution is typical of polygenic trait in a population
• most people in the middle of the bell curve
• less likely to be at the extreme points

Question 24

how to get a higher number of phenotypic classes?

Answer 24

get more genes involved