Classical Genetics

Question 1

one of a pair of genes

Answer 1

allele

Question 2

the trait that is expressed even when combines w/ other alleles

Answer 2

dominant

Question 3

must be two of these alleles present in order for this trait to be expressed

Answer 3

recessive allele

Question 4

individual that is genetically pure for a given trait

possessed two identical alleles

Answer 4

homozygous

Question 5

individual with two different alleles for a given trait

Answer 5

heterozygous

Question 6

outward appearance of an individual w/ respect to a given trait

Answer 6

phenotype

Question 7

genetic characteristics of an individual with respect to a given trait

Answer 7

genotype

Question 8

if two individuals with contrasting, pure-breeding traits are crossed, the trait that is expressed phenotypically in the offspring is the dominant trait
the trait that remains hidden is recessive

Answer 8

Mendel’s Law of Dominance

Question 9

every normal diploid organism has two alleles for each inherited trait (one from the maternal parent and one from the paternal parent)
during meiosis, these alleles segregate, forming gametes that carry only one allele for a given trait
in a monohybrid cross b/w 2 heterozygotes, the phenotypic ratio of the offspring is 3:1

Answer 9

Mendel’s Law of Segregation

Question 10

in a monohybrid cross b/w 2 heterozygotes, the phenotypic ratio of the offspring is _____

Answer 10

in a monohybrid cross b/w 2 heterozygotes, the phenotypic ratio of the offspring is 3:1

Question 11

in a monohybrid cross b/w 2 heterozygotes, the genotypic ratio of the offspring is ______

Answer 11

1 : 2 : 1

Question 12

during meiosis, all allelic combinations are distributed to games w/ equal probability, and the distribution of one pair has no effect on the distribution of another pair (if the genes are unlinked)

Answer 12

Mendel’s Law of Independent Assortment

Question 13

according to mendel’s law of independent assortment, in a dihybrid cross for unlinked genes 1 and 2, the phenotypic ratio of the offspring is _______

Answer 13

9 (dominant for both) : 3 (dominant for 1, recessive for trait 2) : 3 (recessive for trait 1, dominant for trait 2) : 1 (recessive for both traits

Question 14

type of inheritance
usually both males and females affected
if it skips a generation, then the gene is recessive

Answer 14

autosomal recessive inheritance

Question 15

type of inheritance
usually both males and females affected
if it doesn’t skip a generation, then it is dominant

Answer 15

autosomal dominant inheritance

Question 16

type of inheritance
usually be more affected males than females
no male-male transmission
males have a better chance of expressing the trait bc they only have 1 of this type of chromosome from the mother, so genes linked to that chromosome will be expressed
may be masked by dominant gene on female’s other 1 of these chromosomes

Answer 16

X-linked (sex-linked) recessive inheritance

Question 17

blood type
expresses the A antigen
has Anti-B antibody
can donate to A and AB
can receive from A and O

Answer 17

type A blood

Question 18

blood type
expresses B antigen
anti-A antibody
can donate to B and AB
can receive from B and O

Answer 18

type B blood

Question 19

blood type
does not express antibodies
has A and B antigens
can donate to AB
can receive from A, B, AB, and O (*Universal acceptor)

Answer 19

type AB blood

Question 20

blood type
has anti-A and anti-B antibodies
does not express antigens
can donate to A, B, AB, and O (Universal donor)
can receive from O

Answer 20

type O blood

Question 21

probability of producing a genotype that requires multiple events to occur = the ________ of the probability of each event

Answer 21

product

Question 22

probability of producing a genotype that can be the result of multiple events = the _____ of each probability

Answer 22

sum

Question 23

_______ during prophase I of meiosis I can unlink genes

Answer 23

crossing over

Question 24

genes are most likely unlinked when _________

Answer 24

far apart

Question 25

crossing over is more likely on genes that are ______

Answer 25

close together; on homologous chromosomes