Chapter 15, Problem 1P

Match each numbered item with the most closely related lettered item.

a. cytoplasmic segregation	1. transmission of genes through maternal gametes only.
b. heteroplasmic	2. cell that has mtDNA or cpDNAs all of one genotype
c. homoplasmic	3. having gametes of similar size
d. maternal inheritance	4. a cell with a mixture of different mtDNAs generates a daughter cell with only one kind.
e. uniparental inheritance	5. a specific fraction of wild-type organellar DNAs is required for a wild-type phenotype.
f. isogamous	6. cell with mtDNAs or cpDNAs with different genotypes.
g. threshold effect	7. Transmission of genes through either a maternal or a parental gamete, but not both.

Summary Introduction

a.

To determine:

The phrase that describes “cytoplasmic segregation” among the options given below.

1. transmission of genes through maternal gametes only.

2. cell that has mtDNA or cpDNAs all of one genotype

3. having gametes of similar size

4. a cell with a mixture of different mtDNAs generates a daughter cell with only one kind.

5. a specific fraction of wild-type organellar DNAs is required for a wild-type phenotype.

6. cell with mtDNAs or cpDNAs with different genotypes.

7. Transmission of genes through either a maternal or a parental gamete, but not both.

Introduction:

A process in which a cell having many mitochondrial DNA produces a cell having single mitochondrial DNA.

Answer to Problem 1P

Correct answer:

Cytoplasmic segregation: a cell with a mixture of different mtDNAs generates a daughter cell with only one kind.

Explanation of Solution

The cytoplasmic segregation refers to a process where cell containing many different types of mitochondrial DNA result in the generation of a daughter cell, which consists of only one mitochondrial DNA.

Summary Introduction

b.

To determine:

The phrase that describes “heteroplasmic” among the options given below.

1. transmission of genes through maternal gametes only.

2. cell that has mtDNA or cpDNAs all of one genotype

3. having gametes of similar size

4. a cell with a mixture of different mtDNAs generates a daughter cell with only one kind.

5. a specific fraction of wild-type organellar DNAs is required for a wild-type phenotype.

6. cell with mtDNAs or cpDNAs with different genotypes.

7. Transmission of genes through either a maternal or a parental gamete, but not both.

Introduction:

A cell that possess mitochondrial and chlorplast DNA of different genotype.

Answer to Problem 1P

Correct answer:

Heteroplasmic: cell with mtDNAs or cpDNAs with different genotypes is called heteroplasmic.

Explanation of Solution

The heteroplasmic cell consists of either the mitochondrial DNA or the chloroplast DNA that comprises of different genotypes.

Summary Introduction

c.

To determine:

The phrase that describes “homoplasmic” among the options given below.

1. transmission of genes through maternal gametes only.

2. cell that has mtDNA or cpDNAs all of one genotype

3. having gametes of similar size

4. a cell with a mixture of different mtDNAs generates a daughter cell with only one kind.

5. a specific fraction of wild-type organellar DNAs is required for a wild-type phenotype.

6. cell with mtDNAs or cpDNAs with different genotypes.

7. Transmission of genes through either a maternal or a parental gamete, but not both.

Introduction:

A cell that possess mitochondrial and chlorplast DNA of same genotype is called homoplasmic.

Answer to Problem 1P

Correct answer:

homoplasmic: a cell with mtDNAs or cpDNAs all of one genotype.

Explanation of Solution

The homoplasmic cells refer to the eukaryotic cells that have identical mitochondrial and chloroplast DNA.

Summary Introduction

d.

To determine:

The phrase that describes “maternal inheritance” among the options given below.

1. transmission of genes through maternal gametes only.

2. cell that has mtDNA or cpDNAs all of one genotype

3. having gametes of similar size

4. a cell with a mixture of different mtDNAs generates a daughter cell with only one kind.

5. a specific fraction of wild-type organellar DNAs is required for a wild-type phenotype.

6. cell with mtDNAs or cpDNAs with different genotypes.

7. Transmission of genes through either a maternal or a parental gamete, but not both.

Introduction:

When the genes pass from one generation to next only through the means of maternal gametes, the process is called maternal inheritance.

Answer to Problem 1P

Correct answer:

maternal inheritance: transmission of genes through maternal gamete only.

Explanation of Solution

In the case of maternal inheritance, the genes that are transmitted to the offsprings are the ones that come from only the maternal gametes.

Summary Introduction

e.

To determine:

The phrase that describes “uniparental inheritance” among the options given below.

1. transmission of genes through maternal gametes only.

2. cell that has mtDNA or cpDNAs all of one genotype

3. having gametes of similar size

4. a cell with a mixture of different mtDNAs generates a daughter cell with only one kind.

5. a specific fraction of wild-type organellar DNAs is required for a wild-type phenotype.

6. cell with mtDNAs or cpDNAs with different genotypes.

7. Transmission of genes through either a maternal or a parental gamete, but not both.

Introduction:

When genes pass either through male or female or both the gametes, the process is called uniparental inheritance.

Answer to Problem 1P

Correct answer:

uniparental inheritance: transmission of genes through either a maternal or a parental gamete-not both.

Explanation of Solution

In case of uniparental inheritance, the transmission of genes only occurs by one of the parents. It can either be from mother or the father. In this type of inheritance, both the parents are not involved in transmission of genes to the offspring.

Summary Introduction

f.

To determine:

The phrase that describes “isogamous” among the options given below.

1. transmission of genes through maternal gametes only.

2. cell that has mtDNA or cpDNAs all of one genotype

3. having gametes of similar size

4. a cell with a mixture of different mtDNAs generates a daughter cell with only one kind.

5. a specific fraction of wild-type organellar DNAs is required for a wild-type phenotype.

6. cell with mtDNAs or cpDNAs with different genotypes.

7. Transmission of genes through either a maternal or a parental gamete, but not both.

Introduction:

Gametes having similar types of morphology are said to be isogamous.

Answer to Problem 1P

Correct answer:

isogasmous: having gametes of similar size.

Explanation of Solution

In biological terms the gametes that are similar morphologically that is in terms of their shape and size are termed as isogamous.

Summary Introduction

g.

To determine:

The phrase that describes “threshold effect” among the options given below.

1. transmission of genes through maternal gametes only.

2. cell that has mtDNA or cpDNAs all of one genotype

3. having gametes of similar size

4. a cell with a mixture of different mtDNAs generates a daughter cell with only one kind.

5. a specific fraction of wild-type organellar DNAs is required for a wild-type phenotype.

6. cell with mtDNAs or cpDNAs with different genotypes.

7. Transmission of genes through either a maternal or a parental gamete, but not both.

Introduction:

When wild type phenotype is expressed with the help of wild type of organellar DNA, the process is called threshold effect.

Answer to Problem 1P

Correct answer:

threshold effect: a specific fraction of wild type organellar DNAs is required for a wild-type phenotype.

Explanation of Solution

The threshold effect refers to an approach where a small amount of wild type DNA is needed for the expression of a wild type phenotype.