Lecture 19

Question 1

the mendelian theory of inheritance makes a number of specific predictions, one being that offspring will show a trait from either one parent or the other, not a blend of those traits. continued research revealed that inheritance is more complicated than that. many genes follow non-Mendelian inheritance patterns, for example:
incomplete dominance: neither allele is …
codominance: each allele affects the phenotype in a …
(e.g. AB blood type)

Answer 1

completely dominant; distinct way

Question 2

codominant alleles determine whether a person has …, …, or … and … antigens on his or her red blood cells

Answer 2

A; B; A; B

Question 3

polygenic inheritance: many traits are influenced by more than
e.g. parents who each had three alleles coding for dark skin could have children with much lighter/darker skin than either parent, although they are more likely to have children whose skin color is similar to theirs

Answer 3

one gene

Question 4

environment can affect …

Answer 4

phenotype

Question 5

characteristics that are influenced by environmental as well as genetic factors are called

Answer 5

multifactorial

Question 6

even when influenced by the environment, phenotypes have a normal …
human height is an example of a multifactorial characteristic, since it varies based on … and .. but not many people are shorter than 4.5 feet or taller than 7 ft. the range of phenotypic possibilities is called the ….

Answer 6

range; nutrition; genetics; norm of rxn

Question 7

pedigree analysis is used to study … of … within a family

Answer 7

inheritance; genes

Question 8

in humans, males only have 1 allele for many genes located on the

Answer 8

x chromosome

Question 9

solving x-linked inheritance problems;
determine which trait is … or …
assign genotypes to the parents using … for females and … for males. assign alleles for the … chromosomes only using superscripts. use a punnett square

Answer 9

dominant; recessive; XX; XY; X chromosomes only;

Question 10

multiplication rule: the probability of two or more independent events taking place together is calculated by

Answer 10

multiplying their independent probabilities

Question 11

addition rule: the probability of any one of two or more … events is calculated by … the probabilities of these events

Answer 11

mutually exclusive; adding

Question 12

separate genes for separate traits are passed … of one another from parents to offspring

Answer 12

independently

Question 13

allele combinations for a cross for two traits are made by determining the possible combinations of alleles from the two

Answer 13

different genes

Question 14

when both parents are heterozygous for two traits, the offsprint may have any of … possible …

Answer 14

four; phenotype combinations