genetic

Question 1

Mendel’s breeding system

Answer 1

P generation: true breeders (homozygous, one dominant and one recessive)
F1 generation, then cross F1 with itself ot get F2, etc

Question 2

Monohybrid crosses

Answer 2

Follows Mendel’s breeding, looks at 1 character

Question 3

Recessive disorders

Answer 3

Carriers: Rr, carry the diseas but do not have the phenotype

Question 4

Dihybird crosses

Answer 4

looks at 2 characters, true breeding parents for each character (AAbb x aaBB or AABB x aabb)
studies genres on 2 loci on non homologous chromosomes

Question 5

law of independent assortment

Answer 5

when genes are on different chromosones, during meiosis, the allele a gamete receaves is independant of the one another gametes recessives

during metaphase, the pink can line up to the right or to the left, independently of the fact that another pink is on the right

can find the number of possibe different gamete by doing formula 2^n
n:number of heterozyngous gene

Question 6

law of segregation

Answer 6

During the formation of gamete, each gene separates from each other so that each gamete carries only one allele for each gene.

Question 7

Incomplete dominance

Answer 7

neither allele is dominant, the level of dominance is determined by the heterozygous or homozygous of the genes (ex: red, pink, white)

Question 8

Codominance

Answer 8

each allele does for a slightly different protein, but both alleles are visible on the same phenotype ex: blood bype, AB

Question 9

peliotropy

Answer 9

1 genre has multiple phenotypic effect, affects many characters

Question 10

epistasis

Answer 10

effect of one gene is modifiend by one or several other genes ex: a gene masks the expression of another

Question 11

polygenic

Answer 11

multiple independent pairs of gene have additive, so a range of phenotype alont a continuum

Question 12

genes on sex chromosomes

Answer 12

sex chromosomes containt major sex-determining genes, y chromosome determines male sex,
X/Y linked: only on x/y part of chromosome, no independent assortment

females are often carriers or recessive genes, males are more likely to have abnormal phenotypes because of the lack of dominant back up

Question 13

x-inactivation

Answer 13

to compenseate in double dose x chromosome gene, mammals female have 1 x that is mostly inactive in somatic cells, the other inactive will be called a barr body, random and permanent in somatic cells

inactivation is not complete, genes in homologous region are expressed,

Question 14

genes and environment

Answer 14

genes set the limit for the phenotype, environment molds the phenotype within its limits