Biology 1113 Chapter 5 Questions

What was the probability that Deirdre and Geoff's first child would be a girl and express the albino trait? 1/8 1/2 3/4 1/4

1/4

What do we call a genetic cross that follows two separate characters, such as pea seed color and pea seed shape?

A dihybrid cross

This karyotype corresponds to which of the following individuals?

A female with down syndrome

If you are a male, the Law of Independent Assortment indicates that your gametes contain _____.

A random mix of the chromosomes you inherited from each parent

What causes the furrow during cleavage?

A ring of contractile protein fibers pinches the cell in two

What is Deirdre's phenotype?

Albino

What is a carrier?

An individual who is heterozygous for a particular recessive trait

The following F1 cross is made: BBGg × Bbgg. Which is not a possible outcome in the F2 generation?

BbGG

Certain cells taken from umbilical cord blood have the potential to treat illnesses such as lymphoma and leukemia. In what way are cord blood cells useful to treat these diseases?

Cord blood contains stem cells that can be grown and differentiated into some cell types but not all cell types.

If it were to be stretched out, the DNA in one of your cells would be taller than you. How does such a large quantity of DNA fit within the nucleus of one of your cells?

DNA is associated with proteins that compact the DNA to form a package called chromatin

Somatic cells are

Diploid (2n)

A breeder wants to set up a program to produce zebrafish with long fins. Having long fins is a dominant trait compared to the short fin wild type. Before she can market her zebrafish, she needs to perform a test cross on the long-finned fish she plans to use as a breeder. How can she tell whether her fish are homozygous or heterozygous for the long-finned trait?

Do several test crosses between the long-finned fish and the short-finned fish; if the offspring are always long finned, the long-finned parent is probably homozygous.

Mendel's Law of Independent Assortment states that _______

Each pair of alleles segregates independently of the other pairs of alleles

How could an embryonic stem cell be used to repair a severed spine?

Embryonic stem cells can grow into any other cell type, including a nerve cell.

Consider a cell undergoing cytokinesis. You can determine this is a plant cell rather than an animal cell because it has___

Formed a cell plate

Mendel observed that pairs of alleles were separated or segregated in gametes and that they were rejoined in fertilization. We know that pairs of _____ are segregated in _____ and then are rejoined through fertilization.

Homologous chromosomes...meiosis

Huntington's disease is a rare genetic disorder. Which of the following statements regarding the genes for Huntington's must be true?

Huntington's is a mutant trait, but we cannot say whether it is dominant or recessive.

A cell preparing to undergo meiosis duplicates its chromosomes during

Interphase

During which phase of the cell cycle are the chromosomes duplicated?

Interphase

Why are linked genes inherited as a set rather than independently?

Linked genes are located near each other on the same chromosomes, so they tend to move together

Is an individual with the XXY combination of chromosomes anatomically male or female?

Male

When does crossing over occur?

Meiosis 1

When does homologous recombination occur?

Meiosis 1

By what means does a zygote divide?

Mitosis

Which of the following is the correct sequence of events during mitosis?

Nuclear membrane dissolves, chromosomes line up, chromosomes split, nuclear membrane forms

Mendel formulated his principles of inheritance based on _______

Observations on the outcomes of breeding experiments. The underlying processes were unknown at the time

How have Mendel's laws fared as we have learned more about cell biology and processes such as meiosis?

Our new knowledge has helped to explain some of the exceptions to Mendel's laws of inheritance.

Assuming incomplete dominance, if a homozygous red-flowered plant is crossed with a homozygous white-flowered plant, what will be the color of the offspring?

Pink

Fur color in rabbits is controlled by multiple alleles. What does this mean?

Rabbit fur color is controlled by a single gene, but there are multiple versions of that gene.

Except during __________, cell division in humans results in daughter cells that have the same number of chromosomes and are genetically identical to each other and to the parent cell.

Sexual reproduction

Asexual reproduction is a means of creating new individuals solely by mitosis, the form of cell division that creates genetically identical daughter cells.

Sexual reproduction, in contrast, generates genetically unique offspring. To accomplish this, an organism must produce gametes, sperm and egg, through the process of meiosis. The cells produced this way will be haploid, meaning that they contain a single set of chromosomes. Such cells are produced only in the gonads

______ are linked together at the centromere.

Sister chromatids

The inheritance pattern for red-green color blindness is different for males compared to females. Similar to the inheritance pattern for hemophilia in the royal families of Europe, red-green color blindness is rare in females although they can be carriers for this trait. Why is the inheritance pattern different for males and females?

The gene for this trait is located on the X chromosome

Define Mendel's law of assortment.

The inheritance of one character has no effect on the inheritance of another character.

In this life cycle, what do the light- and dark-colored arrows represent?

The light arrows represent haploid stages with 23 chromosomes; the dark arrows represent diploid stages with 46 chromosomes.

The offspring produced via sexual reproduction are genetically ________ to the parents.

Unique

Duplication of a cell occurs

before the cell divides

Imagine that, in cats, eye color is controlled by a single gene and that black eyes are dominant to orange eyes. All the offspring of a cross between a black-eyed cat and an orange-eyed cat have black eyes. This means that the allele for black eyes is __________ the allele for orange eyes.

dominant to

IN animals, meiosis produces four gamete cells

four gamete cells

Meiosis starts with a single diploid cell and produces

four haploid cells

During prophase 1 of meiosis

homologous chromosomes stick together in pairs.

Random orientation of homologous pairs of chromosomes during meiosis I results in alternative arrangements that contribute to genetic variation in offspring. This is called __________.

independent assortment

Crossing over happens during

meiosis

What produces four daughter cells

meiosis

After fertilization, the resulting zygote undergoes______

mitosis

What leads to an individual having too many or two few chromosomes?

nondisjunction

What is the term for the objects inside the white dotted box?

one homologous pair of chromosomes

Which type of gene expression typically generates a continuum (spectrum) of varying phenotypes?

polygenic

During meiosis, segments of nonsister chromatids can trade places. This recombination of maternal and paternal genetic material is a key feature of meiosis. During what phase of meiosis does recombination occur?

prophase 1

The correct order of events during meiosis is

prophase I, metaphase I, anaphase I, telophase I, cytokinesis, meiosis II.

If mitosis makes somatic cells, what does meiosis make?

sex cells

As we now understand it, the Law of Independent Assortment applies _____.

to pairs of genes that are on different chromosomes, but NOT to pairs of genes that are close together on the same chromosome

Like mitosis, meiosis involves duplication of the chromosomes before division starts. However, there are __________ rounds of cell division during meiosis and __________ during mitosis.

two, one

upon fertilization, the egg and sperm fuse to form a single cell called a

zygote