Chapter 15: Transmission of Genetic Information from Parents to Offspring

Question 1

Who used quantitative analysis of carefully designed plant-breeding experiments to arrive at the concept of the gene?

15.1

Answer 1

Gregor Mendel

Question 2

What plant did Mendel use to study inheritance? Why?

15.1

Answer 2

the garden pea, Pisum sativum
certain properties of the garden pea were particularly advantageous for studying inheritance

Question 3

A variant form of a character is called a:

15.1

Answer 3

trait

Question 4

Define inheritance.

15.1

Answer 4

the acquisition of traits by their transmission from parent to offspring

Question 5

T or F: If a true breeding line is allowed to self-fertilize for several generations, the resulting offspring will have the same traits as the parents.

15.1

Answer 5

true

Question 6

A single-factor cross is one in which an experimenter follows:

15.1

Answer 6

the variants of only one character

Question 7

When the true-breeding parents differ in a single character, their offspring are called what?

15.1

Answer 7

monohybrids

Question 8

Plants from two different true-breeding P generation lines are crossed to one another and produce offspring. These offspring are allowed to self-fertilize, which results in the production of…

15.1

Answer 8

F2 generation

Question 9

What is the term that describes when two individuals of the same species with different characteristics are bred/crossed to each other? What are the offspring referred to as?

15.1

Answer 9

hybridization; hybrids

Question 10

The combination of alleles that an individual possesses, such as TT or Tt, is the individual’s:

15.1

Answer 10

genotype

Question 11

What ratio is obtained in the F2 generation of a dihybrid cross when alleles assort independently from one another?

15.1

Answer 11

9:3:3:1

Question 12

What does Mendel’s law of segregation state?

15.1

Answer 12

Alleles of a gene segregate during gamete formation so that half the gametes receive one allele and half receive the second allele.

Question 13

What is a phenotype?

15.1

Answer 13

The phenotype is the physical appearance of an organism. (Plant is short or tall.)

Question 14

Mendel’s Law of Independent Assortment states that:

15.1

Answer 14

allels of two different genes assort independently in the formation of gametes

Question 15

What are the principles of the chromosome theory of inheritance?

15.2

Answer 15

1. genes are found in the chromosomes
2. chromosomes are replicated and passed from parent to offspring and from cell to cell
3. during meiosis, the homologous pairs segregate independently and haploid gametes are produced
4. gametes are haploid cells that combine to form a diploid cell during fertilization
5. the nucleus of a diploid cell contains homologous pairs of chromosomes

Question 16

The analysis of an inherited trait over several generations in one family is called:

15.3

Answer 16

pedigree analysis

Question 17

What is a gene’s locus?

15.2

Answer 17

its physical location on a chromosome

Question 18

What type of allele is common, and which is rare?

15.3

Answer 18

wild-type is common
mutant is rare

Question 19

What phase of cellular division explains Mendel’s law of independent assortment?

15.2

Answer 19

metaphase of meiosis I

Question 20

The random alignment of chromosomes ____________ leads to the independent assortment of alleles on different chromosomes.

15.2

Answer 20

in meiosis I

Question 21

What is represented in pedigree analysis?

15.3

Answer 21

Inheritance of an inherited trait over several generations in one family

Question 22

What observations in a pedigree would rule out a recessive pattern of inheritance for a human disease?

15.3

Answer 22

an unaffected offspring has two affected parents

Question 23

In a simple dominant/recessive relationship, the production of approximately ____% of the protein needed in the heterozygote is plenty for the individual to function typically.

15.4

Answer 23

50%

Question 24

Because a single gene can be expressed in multiple cell types or at several stages of development, a phenomenon called ____ could occur.

15.4

Answer 24

pleiotropy

Question 25

A characteristics of incomplete dominance is the presence of an intermediate phenotype in the:

15.4

Answer 25

heterozygote

Question 26

T or F: In recessive inheritance, two affeccted parents will sometimes produce affected offspring.

15.3

Answer 26

false; ALL of the offspring of two affected individuals are affected themselves (always)

Question 27

If a cross between heterozygotes for a single trait results in three distinct phenootypes, which of the following types of inheritance is likely the reason?

15.4

Answer 27

incomplete dominance

Question 28

T or F: Some heterozygotes up-regulate expression of the dominant allele to compensate for a lack of function in a recessive allele.

15.4

Answer 28

true

Question 29

A researcher is studying members of true-breeding strains that have the same geontypes by subjecting them to differnet environmental conditions. The phenomenon that is being evaluated here is likely the:

15.4

Answer 29

norm of reaction

Question 30

A defect in a microtubule protein may affect cell divison as well as cell movement. This is an example of:

15.4

Answer 30

pleiotropy

Question 31

In incomplete dominance, a cross of two heterozygotes produces ____ in the offspring.

15.4

Answer 31

three distinct phenotypes

Question 32

Genes found on one sex chromosome but not the other are called:

15.5

Answer 32

sex-linked genes

Question 33

A trait that causes a disease will occur more frequently in males than females if the trait is:

15.5

Answer 33

recessive and X-linked

Question 34

Sons receive X-linked recessive alleles from their ____ who are carriers.

15.5

Answer 34

mothers

Question 35

What species do the following sex chromosomes belong to?
X-Y, X-O, Z-W, halpoid-diploid.

Answer 35

humans; insects, birds, bees