Chapter 6: Extranuclear Inheritance, Imprinting, and Maternal Effect

Question 1

Simple Mendelian Inheritance describes inheritance patterns that obey

Answer 1

The Law of Segreagtion
The Law of Independent Assortment

Question 2

Genes are passed _______ from generation to generation ( except for rare mutations)

Answer 2

unaltered

Question 3

Expression of the genes __ ____ __________ directly influence their traits

Answer 3

in the offspring

Question 4

Extranuclear Inheritance

Answer 4

genes not in the nucleus

Question 5

Nuclear genes

Answer 5

located on a chromosome in the nucleus

Question 6

Extranuclear Inheritance
(AKA cytoplasmic inheritance)

Answer 6

traits are not inherited through genes that are in the nucleus, but are in other organelles.

Question 7

The two most important examples of Extranuclear are genes in the

Answer 7

Mitochondria and Chloroplasts.

Question 8

The genome of both mitochondria and chloroplasts is composed of a

Answer 8

single circular double-stranded chromosome (DNA)

Question 9

Chromosomes of mitochondria and chloroplasts are found in

Answer 9

Nucleoids

Question 10

Maternal Inheritance

Answer 10

Extranucelear. Mitochondrial DNA comes only from the mother. (mtDNA)

Question 11

Paternal leakage

Answer 11

mitochondria provided through the sperm. rare

Question 12

Human Mitochondrial Disease
two mechanisms:

Answer 12

1. Transmitted from mother to offspring via the egg.
2. Mutations can occur in somatic cells during aging.

Question 13

Symptoms of mitochondrial disease depend on

Answer 13

the ratio of mutant to normal mitochondria

Question 14

The endosymbiosis theory

Answer 14

mitochondria and chloroplasts originated from bacteria that took up residence within a primordial cell.

Question 15

Chloroplast originated from

Answer 15

cyanobacterium

Question 16

Mitochondria originated from

Answer 16

gram-negative nonsulfur purple bacteria

Question 17

Epigenetic inheritance

Answer 17

modification to a gene that changes gene expression, but is not permanent over the course of generation.

Question 18

Epigenetic inheritance may permanently effect

Answer 18

the life of an individual

Question 19

epigenetic inheritance has

Answer 19

no change in the DNA sequence itself

Question 20

__________ changes may be inherited, but may not follow Mendelian inheritance

Answer 20

Epigenetic

Question 21

DNA and Chromosomal modifications can occur during ___________ or early ___________ ____________

Answer 21

Gametogenesis, embryonic development

Question 22

Two examples of epigenetic inheritance

Answer 22

1. X-chromosome inactivation
2. genomic imprinting

Question 23

Genomic imprinting

Answer 23

modification occurs to a nuclear gene that alters gene expression but is not permanent over many generations.

Question 24

Expression of a gene depends on

Answer 24

if it is inherited from the male or female parent

Question 25

Phenotypes controlled by imprinted genes have a

Answer 25

non-Mendelian pattern of inheritance

Question 26

Monoallelic expression

Answer 26

offspring expresses either the maternally or paternally inherited phenotype.

Question 27

Stages of Imprinting

Answer 27

1. Establishment
2. Maintenance
3. Earasure and re-establishment

Question 28

Establishment

Answer 28

of the imprint during gametogenesis

Question 29

maintenance

Answer 29

of the imprint during embryogenesis and in the adult somatic cells

Question 30

erasure and re-establishment

Answer 30

of the imprint in the germ cell

Question 31

Genomic imprinting is permanent in the somatic cells of one animal but …

Answer 31

it can be altered from one gen. to another.

Question 32

Genomic imprinting occurs in several species including

Answer 32

mammals
insects
plants

Question 33

Genomic imprinting may involve

Answer 33

a single gene
a part of a chromosome
an entire chromosome
all chromosomes from one parent

Question 34

Methylation of DNA bases is part of

Answer 34

genomic imprinting

Question 35

Imprinting Control Regions (ICRs) are

Answer 35

*located near the imprinted genes
*methylated either in the oocyte or sperm but not both.
* contain transcription factor binding sites

Question 36

Maternal Effect

Answer 36

a phenotype is determined by the mother’s genotype.

Question 37

The Non-Mendelian inheritance pattern of maternal effect genes can be explained by the

Answer 37

Process of Oogenesis