Chapter 9 Mastering Biology

Female?

XX

Attached earlobes are recessive to free earlobes. What genotypic ratio is expected when an individual with attached earlobes mates with an individual heterozygous for free earlobes?

1:1

In humans, free earlobes (E) are dominant to attached earlobes (e) and the presence of freckles (F) is dominant to the absence of freckles (f). If an individual heterozygous for both of these traits were to mate with an individual with attached earlobes and no freckles, what is the probability of having a child with attached earlobes and freckles?

25%

A purebred plant that produces yellow seeds is crossed with a purebred plant that produces green seeds. The F1 plants have yellow seeds. What is the expected phenotypic ratio of seed color of the offspring of an F1 × F1 cross?

3:1

GgTt pea plants can produce ____ type(s) of gamete(s) but a ggtt plant can produce___ type(s) of gamete(s)

4....1

Achondroplasia is a form of dwarfism caused by a dominant allele. The homozygous dominant genotype causes death, so individuals who have this condition are all heterozygotes. If a person with achondroplasia mates with a person who does not have achondroplasia, what percentage of their children would be expected to have achondroplasia?

50%

Attached earlobes are recessive to free earlobes. What is the probability of having a child with attached earlobes when an individual with attached earlobes mates with an individual heterozygous for free earlobes?

50%

A couple has two female children. What is the probability that their next child will be male?

50% (it is not affected by the previous children)

Using recombination data, it is possible to determine the location of genes on a chromosome. The result is _____.

A linkage Map

What data or test would you seek to determine whether or not a trait is sex linked?

A pedigree

What is a test cross used to do?

A testcross is used to determine whether an individual expressing the dominant phenotype is homozygous dominant or heterozygous

A ______ is one particular variation of a character

A trait

Hypophosphatemia (vitamin Dresistant rickets) is inherited as a sex-linked dominant trait. The relevant gene is found on the X chromosome. What is the expected outcome of a cross between a homozygous recessive woman and a man with hypophosphatemia?

All of their daughters and none of their sons exhibit hypophosphatemia

Most human genes come in alternate versions called...

Alleles

Alleles are described as

Alternate versions of a gene

Which of the following techniques is used to collect fetal cells during pregnancy for genetic testing?

Amniocentesis

An individual who is homozygous ______.

Carries two copies of the same allele for a gene

A _____ is an inherited feature that varies from individual to individual

Character

The most common lethal genetic disease in the US is ______ (doctors pound on your back)

Cystic Fibrosis

An important technique that helps provide insight into interesting genetic questions at the molecular level, such as reasons for hairless dogs, is called ______

DNA sequencing

In humans, the presence or absence of dimples is a trait controlled by a single gene. What is the genotype of an individual who is heterozygous for dimples?

Dd

If an organism has two non identical versions of a gene, the one that is expressed in the organism is called the ____ allele

Dominant

Epistasis

Exact opposite of pleiotropy, many genes giving you a single trait

According to Mendel's law of segregation, ________.

Gametes have one allele copy for each gene

The______ is the genetic makeup of the organism

Genotype

Mendel crossed purebred purple-flowered plants with purebred white-flowered plants, and all of the resulting offspring produced purple flowers. The offspring are all ______, and the allele for purple flowers is ______.

Heterozygotes... Dominant

A plant with the genotype AABbcc _______

Homozygous for 2 different genes

In general, the frequency with which crossing over occurs between two linked genes depends on __________.

How far apart they are located on a chromosome

A mating beween a purebred purple-flowered pea plant and a purebred white-flowered pea plant would produce a(n) _____

Hybrid

Polygenic Inheritance

If you have many genes leading to a single trait Another way of saying epistasis

To determine the genotype of an individual who expresses a dominant trait, you would cross that individual with an individual who ______.

Is homozygous recessive for that trait

________ genes violate Mendel's principle of independent assortment.

Linked

What name is given to the specific location of a gene on a chromosome?

Locus

In humans, the __________ determines the sex of the offspring because __________.

Male.... the male can contribute either an X making it a female or a Y making it a male

Epigenetics and Role of Environment

Many phenotypic characteristics result from a combination of heredity and environment

An individual with the genotype AaBb produces four different gametes in equal proportions. This is a demonstration of ______.

Mendel's law of independent assortment

Law of Segregation

Mendel's law of segregation is based on gametes getting only one copy of each allele of each gene.

A genetic cross involving parents that differ in a single character is called a ______

Monohybrid Cross

Red-green color blindness is inherited as a sex-linked recessive trait. The gene is found on the X chromosome. Can a man with normal color vision have a daughter who is red-green color-blind?

No,he can't (unless there is a mutation)

The physical traits are called

Phenotypes

The percentage of recombinant phenotypes resulting from fertilization involving recombinant gametes is called _____.

Recombination Frequency

A gene that is located on a sex chromosome (X or Y chromosome) is __________.

Sex linked gene

Experience with dog breeding has taught geneticists ________.

That geographically isolated groups of dogs may be selected for quite different traits, resulting in different dog breeds

What is the basis of Mendel's laws?

The behavior of chromosomes during metaphase I and anaphase I of meiosis

Why are human males much more likely than human females to inherit the recessive condition hemophilia (a failure of the blood to clot properly)?

The gene for hemophilia is sex-linked

Pleiotropy

When one gene influences several characters

The _____ is most commonly found in nature

Wild type trait (hint: wild)

Male?

XY

AA purebred plant that produces yellow seeds is crossed with a purebred plant that produces green seeds. The seeds of all of the offspring are yellow. Why?

Yellow is dominant to the green allele

A individual heterozygous for cystic fibrosis

is a carrier

The best definition of a purebred plant is one that ______.

self fertilizes to produce offspring identical to the parent

The Chromosomal Basis of Inheritance

states that genes are located at specific positions on a chromosome

The most common phenotype in a natural population is referred to as the __________.

wild type