Chapter 1 Achieve Homework, Reading, and Lecture Notes

Question 1

Which of these describes a genome?

A) The alleles in an eggshell
B) The protein-coding genes in a cell or organism
C) The introns in a cell or organism
D) The collection of genetic material in a cell or organism

Answer 1

D

D) The collection of genetic material in a cell or organism

Question 2

Suppose that life exists elsewhere in the universe. All life must contain genetic information, but alien genomes might not contain nucleic acids or have the same features as those found in the genomes of life on Earth. What might be the common feature of all genomes, no matter where they exist? (Multiple answers)

A) A large and varying number of building blocks that can reflect the complexity of living organisms
B) The ability to allow acquired traits to become incorporated into the genetic material
C) The ability to replicate the genetic information accurately for the next generation
D) Must not be able to mutate to new forms
E) The ability to store the entire set of information an organism needs for reproduction and development

Answer 2

C and E

C) The ability to replicate the genetic information accurately for the next generation

E) The ability to store the entire set of information an organism needs for reproduction and development

Question 3

What is the most inclusive definition of a model organism (model system)?

A) An animal that is evolutionary closely related to humans

B) An organism with a biological system that is representative of the same system in other organisms

C) An animal on which new treatments can be easily tested

D) An organism with a digestive system similar to that of humans

Answer 3

B

B) An organism with a biological system that is representative of the same system in other organisms

Question 4

Which of the statements are reasons why kangaroos would be a poor choice as model organisms for studying ovarian cancer? (Multiple answers)

A) They are marsupials and are too different from other mammals for studying

B) They produce very few offspring at a time and thus require a lot of time to collect meaningful data

C) They are needlessly large when smaller, more easily handled organisms, such as mice, are available

D) They do not get ovarian cancer nd are thus inappropriate models for ovarian cancer research

Answer 4

A, B, and C

A) They are marsupials and are too different from other mammals for studying

B) They produce very few offspring at a time and thus require a lot of time to collect meaningful data

C) They are needlessly large when smaller, more easily handled organisms, such as mice, are available

Question 5

Which agriculture and animal domestication practices demonstrate a rudimentary understanding of heredity and genetics? (Multiple answers)

A) Farmers planted seeds from trees that produced the largest, sweetest fruits and not from tees that had the smallest or inedible fruits

B) Primitive societies were more likely to kill wolves that were too aggressive and keep the less aggressive ones as pets and hunting companions

C) To prevent injury to other livestock, ranchers removed the horns from bulls after birth

D) Nomads selected sheep with the highest-quality wool for breeding

E) When foraging for edible plants, gatherers avoided grasses with no nutritional value

Answer 5

A, B, and D

A) Farmers planted seeds from trees that produced the largest, sweetest fruits and not from tees that had the smallest or inedible fruits

B) Primitive societies were more likely to kill wolves that were too aggressive and keep the less aggressive ones as pets and hunting companions

D) Nomads selected sheep with the highest-quality wool for breeding

Question 6

The first cell was discovered in 1665 by Robert Hooke, who observed non-living cells of cork using a crude microscope and noted that they looked like “tiny rooms in which a monk might live.” Almost one decade later, Anton van Leeuwenhoek observed the first living cells, which he dubbed ‘animalcules’, meaning little animals. Scientists continued to use these early microscopes to observe cells for over a century and repeatedly found the cell to be the discrete unit of life. These observations culminated in 1824 with Renee Dutrochet declaring the cell to be the fundamental element of organization.

Which tenet of cell theory is described by the paragraph about the historical observations of cells?

A) All metabolism transpires within cells
B) All cells come from preexisting cells
C) All organisms are composed of one or more cells
D) The cell is the basic unit of every organisms

Answer 6

D

D) The cell is the basic unit of every organism

Question 7

Match each description to the term it defines.

Terms: Gene, allele, chromosome

Descriptions: long DNA molecules visible during mitosis, a function unit of heredity, a short segment of a chromosome that codes for an RNA molecule, an alternative forms of a particular gene, and large genetic element that carries genes essential to cellular function

Answer 7

Gene: A short segment of a chromosomes that codes for an RNA molecule, a functional unit of heredity

Allele: an alternative forms of a particular gene

Chromosome: long DNA molecules visible during mitosis, large genetic element that carries genes essential to cellular function

Question 8

How does the structure of DNA encode genetic information?

A: The sequence of amino acids
B: The structure of the bases
C: The sequence of bases
D: The length of the DNA molecule

Answer 8

C

C: The sequences of the bases (nucleotides

Question 9

What is the central dogma of molecular biology?

Answer 9

Replication (two lines), transcription (one line with “teeth”), translation (one line) [The “dogma” itself is how DNA replicates]

Question 10

Match each description to the term it defines.

Term: Allele, genotype, phenotype

Description: BB, the genetic makeup of an organism, the physical expression of a gene, a variation of a gene, B or b, freckles

Answer 10

Allele: a variation of a gene, B or b

Genotype: the genetic makeup of an organism, BB

Phenotype: the physical expression of a gene, freckles

Question 11

What are the structures in a cell that group genes together, are composed of chromatin (DNA and protein), and become visible under a light microscope during mitosis?

A) Chromosomes
B) Nucleic acids
C) Centrioles
D) Centromeres

Answer 11

A

A) chromosomes

Question 12

How should the following statement be categorized?

“Analysis of pedigrees to determine the probability of someone inheriting a trait”

A) Population genetics
B) Transmission genetics
C) Molecular genetics

Answer 12

B

B) Transmission genetics

Question 13

How should the following statement be categorized?

“Study of people on a small island to determine why a genetic form of asthma is so prevalent.”

A) Population genetics
B) Transmission genetics
C) Molecular genetics

Answer 13

A

A) Population genetics

Question 14

How should the following statement be categorized?

“Effect of nonrandom mating on the distribution of genotypes among a group of animals.”

A) Population genetics
B) Transmission genetics
C) Molecular genetics

Answer 14

A

A) Population genetics

Question 15

How should the following statement be categorized?

“Examination of the nucleotide sequences found at the ends of chromosomes.”

A) Population genetics
B) Transmission genetics
C) Molecular genetics

Answer 15

C

C) Molecular genetics

Question 16

How should the following statement be categorized?

“Mechanisms that ensure a high degree of accuracy during DNA replication.”

A) Population genetics
B) Transmission genetics
C) Molecular genetics

Answer 16

C

C) Molecular genetics

Question 17

How should the following statement be categorized?

“Study of how the inheritance of traits encoded by genes on sex chromosomes differed from the inheritance of traits encoded by genes on nonsex chromosomes.”

A) Population genetics
B) Transmission genetics
C) Molecular genetics

Answer 17

B

B) Transmission genetics

Question 18

Section 1.1 Review (just lots of important info on what to take away from this section)

Answer 18

Learning objective: Be able to explain the importance of genetics

Genetics is central to every person’s life: it influences a person’s physical features, personality, intelligence, and susceptibility to numerous diseases.

Genetics plays essential roles in agriculture, the pharmaceutical industry, and medicine. It is central to the study of biology.

All organisms use similar genetic systems. Genetic variation is the foundation of evolution and is critical to understanding all life.

The genetics can be broadly divided into transmission genetics, molecular genetics, and population genetics.

Model genetic organisms are species about which much genetic information exists because they have characteristics that make them particularly amenable to genetic analysis.

Question 19

Section 1.2 Review (just lots of important info on what to take away from this section)

Answer 19

Learning objectives: Be able to describe the history of genetics

The use of genetics by humans began with the domestication of plants and animals.
Ancient Greeks developed the concepts of pangenesis and the inheritance of acquired characteristics, which were later disproved.

Preformationism suggests that a person inherits all of their traits from one parent. Blending inheritance proposes that offspring possess a mixture of parental characteristics. These ideas were later shown to be incorrect.

By studying the offspring of crosses between varieties of peas, Gregor Mendel discovered the principles of heredity.

Developments in cytology in the nineteenth century led to the understanding that the cell nucleus is the site of heredity.

In 1900, Mendel’s principles of heredity were rediscovered. Population genetics was established in the early 1930s, followed by bacterial and viral genetics.

The structure of DNA was discovered in 1953, stimulating the rise of molecular genetics.

The first human whole-genome sequence was completed in 2003.

Question 20

Section 1.3 Review (just lots of important info on what to take away from this section)

Answer 20

Learning objectives: Be able to explain basic concepts of heredity

There are two basic types of cells: eukaryotic and prokaryotic

The set of alleles that determines a trait is termed the genotype; the trait that they produce is the phenotype

Genes are located on chromosomes, made up of nucleic acids and proteins, and are partitioned into daughter cells through mitosis or meiosis.

Genetic information is expressed by transferring information from DNA to RNA to proteins.

Evolution requires a genetic change in populations.

Question 21

Define genetics

Answer 21

The study of heredity-how inherited variation is encoded, replicated, expressed, and how it evolves.

Question 22

Define genome

Answer 22

The complete set of genetic instructions for any organism; all genomes are encoded in nucleic acids-either DNA or RNA

Question 23

Define transmission genetics

Answer 23

Also known as classical genetics, ____________ ________ encompasses the basic principles of heredity and how traits are passed from one generation to the next

Question 24

Define molecular genetics

Answer 24

_________ ________ concerns the chemical nature of the gene itself: how genetic information is encoded, replicated, and expressed

Question 25

Define population

Answer 25

Groups of individuals of the same species

Question 26

Define population genetics

Answer 26

__________ ________ explores the genetic composition of populations and how that composition changes geographically and with time

Question 27

Define model genetic organism.

Answer 27

Organisms widely used in genetic research that can serve as models for the genetic systems of other organisms

Question 28

Define pangenesis

Answer 28

A concept developed by Greek philosophers that suggested that specific pieces of information travel from various parts of the body to reproductive organs, from which they are passed to the embryo at the moment of conception

Question 29

Define inheritance of acquired characteristics.

Answer 29

The concept of pangenesis led the ancient Greeks to propose the notion of the ___________ __ ________ _______________, according to which traits acquired in a person’s lifetime become incorporated into that person’s hereditary information and are passed on to offspring.

Question 30

Define preformationism

Answer 30

A theory that inside the egg or sperm, there exists a fully formed miniature adult, a homunculus, which simply enlarges in the course of development

Question 31

Define blending inheritance

Answer 31

An early notion of heredity proposed that the traits of offspring are a blend or mixture of parental traits

Question 32

Define cell theory

Answer 32

Developed by Matthias Jacob Schleiden and Theodor Schwann, it is a theory that all life is composed of cells, cells arise only from preexisting cells, and the cell is the fundamental unit of structure and function in living organisms.

Question 33

Define germ-plasm theory

Answer 33

A theory proposed by August Weismann which holds that the cells in the reproductive organs carry a complete set of genetic information that is passed to the egg and sperm

Question 34

Concept Check #1: Our genes affect our physical features and susceptibility to diseases and disorders. Genetics contributes to advances in agriculture, pharmaceuticals, and medicine and is fundamental to modern biology. All organisms use similar genetic systems, and genetic variation is the foundation of the diversity of all life.

What are some of the implications of all organisms having similar genetic systems?

A) That all life forms are genetically related
B) That research findings on one organism’s gene function can often be applied to other organisms
C) That genes from one organism can often function in another organism
D) All of the above

Answer 34

D

D) All of the above

Question 35

Concept Check #2: The three significant divisions of genetics are transmission, molecular, and population genetics. Transmission genetics examines the principles of heredity; molecular genetics deals with the gene and the cellular processes by which genetic information is transferred and expressed; and population genetics concerns the genetic composition of groups of organisms and how that composition changes over time and space. Model genetic organisms are species that have received particular emphasis in genetic research: they have characteristics that make them useful for genetic analysis.

Would the horse make a good model genetic organism? Why or why not?

Answer 35

No, because horses are expensive to house, feed, and propagate, they have too few progeny, and their generation time is too long

Question 36

Concept Check #3: Humans first applied genetics to the domestication of plants and animals between 10,000 and 12,000 years ago. Plant hybridization and cytology developments in the eighteenth and nineteenth centuries laid the foundation for the field of genetics today. After Mendel’s work was rediscovered in 1800, the science of genetics developed rapidly, and today is one of the most active areas of science.

How did developments in cytology in the nineteenth century contribute to our modern understanding of genetics?

Answer 36

Developments in cytology in the 1800s led to identifying parts of the cell, including the cell nucleus and chromosomes. The cell theory focused biologists’ attention on the cell, concluding that the nucleus contains hereditary information.

Question 37

How did Hopi culture contribute to the high incidence of albinism among members of the Hopi tribe?

Answer 37

In the Hopi culture, people with albinism were considered unique and given special status. Because extensive exposure to sunlight could be damaging or deadly, Hopi males with albinism do no agricultural work. Males with albinism had more children, thus increasing the frequency of the albino mutation. Finally, the small size of the Hopi population may have helped increase the frequency of the albino mutation, owing to chance.

Question 38

How are genetics and evolution related?

Answer 38

Evolution is genetic change over time. Genetic variation must first arise for evolution to occur, and then evolutionary forces change the proportions of genetic variants over time. Genetic variation is, therefore, the basis of all evolutionary change.

Question 39

Genetics is considered both an ancient and a young science. Explain what this means.

Answer 39

Genetics is “old” because humans have been aware of hereditary principles for thousands of years and have applied them since the beginning of agriculture and the domestication of plants and animals. It is very “young” in the sense that the fundamental principles were not uncovered until Mendel’s time, and the discovery of the structure of DNA and the principles of recombinant DNA occurred only within the past 70 years

Question 40

Which term is described below?

“Each reproductive cell contains a complete set of genetic information.”

A) Preformationism
B) Pangenesis
C) Germ-plasm theory
D) Inheritance of acquired characteristics

Answer 40

C

C) Germ-plasm theory

Question 41

Which term is described below?

“All traits are inherited from one parent.”

A) Preformationism
B) Pangenesis
C) Germ-plasm theory
D) Inheritance of acquired characteristics

Answer 41

A

A) Preformationism

Question 42

Which term is described below?

“Genetic information may be altered by the use of a characteristic.”

A) Preformationism
B) Pangenesis
C) Germ-plasm theory
D) Inheritance of acquired characteristics

Answer 42

D

D) Inheritance of acquired characteristics

Question 43

Which term is described below?

“Cells of different tissues contain different genetic information.”

A) Preformationism
B) Pangenesis
C) Germ-plasm theory
D) Inheritance of acquired characteristics

Answer 43

B

B) Pangenesis

Question 44

Compare and contrast Pangenesis and Germ-plasm theory.

Answer 44

Pangenesis postulates that pieces of genetic information travel from all parts of the body to the reproductive organs and that genetic information is then converted to the embryo. According to the germ-plasm theory, gamete-producing cells within the reproductive organs contain genetic information passed to the gametes. Pangeneiss and the germ-plasm theory are similar in that both propose that genetic information is contained in discrete units passed on to offspring. They differ in where that genetic information resides. In pangenesis, it lives in different parts of the body and must travel to the reproductive organs. In the germ-plasm theory, all the genetic information is already in the reproductive cells.

Question 45

Compare and contrast preformationism and blending inheritance.

Answer 45

Preformationism holds that the sperm or egg contains a miniature preformed adult called a homunculus that grows to produce offspring. Only one parent contributes genetic traits to the offspring. Blending inheritance requires contributions of genetic material from both parents. The genetic contributions from the parents blend to produce the offspring’s genetic material. Having been blended, the genetic material cannot be separated in future generations

Question 46

Compare and contrast The inheritance of acquired characteristics and our modern theory of heredity.

Answer 46

The inheritance of acquired characteristics postulates that traits acquired in a person’s lifetime alter the genetic material and can be transmitted to offspring. Our modern theory of heredity states that offspring inherit genes located on chromosomes passed to them by their parents. These chromosomes segregate in the parent germ cells in meiosis and are passed into the gametes.

Question 47

Compare and contrast eukaryotic and prokaryotic cells.

Answer 47

Eukaryotic cells have a nucleus containing chromosomal DNA and possess internal membrane-bounded organelles. Prokaryotic cells have neither of these features.

Question 48

Compare and contrast Genes and alleles.

Answer 48

A gene is a basic unit of hereditary information, usually encoding an RNA molecule or a protein. Alleles are variant forms of a gene arising through mutation.

Question 49

Compare and contrast genotype and phenotype.

Answer 49

The genotype is the set of alleles inherited by an organism from its parent(s). The expression of the genes of a particular genotype, through interaction with environmental factors, produces the phenotype, the observable trait.

Question 50

Compare and contrast DNA and RNA.

Answer 50

Both are nucleic acid polymers. RNA contains a ribose sugar, whereas DNA contains a deoxyribose sugar. RNA also contains uracil as one of the four bases, whereas DNA contains thymine. The other three bases are common to both DNA and RNA. Finally, DNA is usually double-stranded, consisting of two complementary strands, whereas RNA is single-stranded.

Question 51

Compare and contrast DNA and chromosome.

Answer 51

Chromosomes are structures of DNA and associated proteins. The DNA contains the genetic information

Question 52

What are the three significant subdisciplines in the diversity of genetics?

Answer 52

Transmission genetics, molecular genetics and population genetics

Question 53

What does transmission genetics address?

Answer 53

The relation between chromosomes and heredity

The arrangement of genes on chromosomes

Gene mapping

Question 54

What is the focus of transmission genetics?

Answer 54

Focuses on the individual organism

How an individual inherits their genetic makeup

How it passes its genes to the next generation

Question 55

What does molecular genetics include?

Answer 55

The cellular processes of replication, transcription, and translation (how genetic information is transferred from one molecule to another)

Gene regulation (the process that controls the expression of genetic information

Question 56

What is the focus of molecular genetics?

Answer 56

The focus is on the gene and its structure, organization, and function.

Question 57

What is the focus of population genetics?

Answer 57

The focus is the group of genes found in a population.

Question 58

What four things are required for a good model genetic organism?

Answer 58

1. Short generation time
2. Large but manageable numbers of progeny
3. Adaptability to a laboratory environment
4. Ability to be housed and propagated inexpensively

Question 59

What year did biologists recognize that the cell nucleus contains hereditary information?

Answer 59

1855

Question 60

What are the three points of Cell Theory?

Answer 60

1. All life is composed of cells
2. Cells arise only from preexisting cells
3. The cell is the fundamental unit of structure and function in living organisms

Question 61

Who gave genetics its name?

Answer 61

William Bateson in the year 1901

Question 62

What are the fundamental properties of a gene?

Answer 62

Replication, form generation and mutations

Question 63

Define diploid

Answer 63

containing two complete sets of chromosomes, one from each parent

Question 64

Define haploid

Answer 64

The presence of a single set of chromosomes in an organism’s cells

Question 65

Define homologous

Answer 65

a gene inherited in two species from a common ancestor