Chapter 2_Mendelian Inheritance

Question 1

Pangenesis

Answer 1

The first attempt to explain the transmission of hereditary traits from generation to generation. Seeds are produced by all parts of the body, which are then collected and transmitted to the offspring at the time of conception. Seeds cause certain traits of the offspring to resemble those of the parents.

Question 2

Blending Inheritance

Answer 2

The factors that dictate hereditary traits can blend together from generation to generation. The blended traits would then be passed to the next generation.

Question 3

Hybridization Experiment

Answer 3

When two distinct individuals with different characteristics are mated, or crossed, to each other. The offspring are referred to as hybrids.

Question 4

Why were garden peas advantageous for studying plant hybridization?

Answer 4

• 1. The species was available in several varieties that had decisively different physical characteristics.
• 2. The ease of making crosses. Mendel was able to pry open immature flowers and remove the anthers before they produced pollen. Therefore, these flowers could not self fertilize. He would then obtain pollen from another plant by gently touching its mature anthers with a paintbrush. He applied this pollen to the stigma of the flower that already had its anthers removed.

Question 5

Another name for true breeding

Answer 5

Strain

Question 6

Particulate Theory of Inheritance

Answer 6

The genes that govern traits are inherited as discrete units that remain unchanged as they are passed from parent to offspring.

Question 7

Law of Segregation

Answer 7

The two copies of a gene segregate from each other during transmission from parent to offspring. Therefore, only one copy of each gene is found in a gamete. At fertilization, two gametes combine randomly, potentially producing different allelic combinations.

Question 8

Law of Independent Assortment

Answer 8

Two different genes will randomly assort their alleles during the formation of haploid cells. In other words, the allele for one gene will be found within a resulting gamete independently of whether the allele for a different gene is found in the same gamete.

Question 9

Genetic recombination

Answer 9

A combination of alleles that differs from those in the parental generation.

Question 10

Loss of function alleles

Answer 10

A defective copy of a gene

Question 11

How are loss of function alleles informative?

Answer 11

Such alleles provide critical clues concerning the purpose of the protein’s function within the organism.

Question 12

Pedigree analysis

Answer 12

The use of information on family trees to determine the type of inheritance pattern a gene will follow.

Question 13

Pedigree analysis is commonly used…

Answer 13

…to determine the inheritance pattern of human genetic diseases.

Question 14

Random sampling error

Answer 14

The deviation between the observed and expected outcomes.

Question 15

Sum Rule

Answer 15

The probability that one of two or more mutually exclusive events will occur is equal to the sum of the individual probabilities of the events.

Question 16

Product Rule

Answer 16

The probability that two or more independent events will occur is equal to the product of their individual probabilities.

Question 17

Multinomial expansion equation

Answer 17

Needed to solve unordered genetic problems that involve three or more phenotypic categories.

Question 18

Hypothesis testing

Answer 18

Determine if the data from genetic crosses are consistent with a particular pattern of inheritance.

Question 19

Goodness of fit

Answer 19

(Null Hypothesis) Assumes there is no real difference between the observed and expected values.

Question 20

Can statistics prove a hypothesis?

Answer 20

No, they can only provide insight as to whether or not the observed data seem reasonably consistent with the hypothesis.

Question 21

Chi Square test

Answer 21

Used to determine goodness of fit. (often written as x^2).

Question 22

P values

Answer 22

The probabilities allow us to determine the likelihood that the amount of variation indicated by a given chi square value is due to random chance alone, based on a particular hypothesis.

Question 23

High vs. Low chi square value

Answer 23

High means that the high deviation has occurred because the hypothesis is incorrect. Low indicates a high probability that the observed deviations could be due to random chance alone.

Question 24

Degrees of freedom

Answer 24

A measure of the number of categories that are independent of each other.