Biology - Chapter 8

Select all of the following that are true about cancer risk.

Cancer risk increases with age. Genetic mutations can cause cancer. Chemicals or radiation in the environment can cause mutations that lead to cancer. Mutated genes that cause cancer can be inherited.

Select all of the following that act as controls of cell division.

Cell cycle checkpoints External growth factors

What enzyme adds complementary bases to exposed single strands of DNA during DNA replication?

DNA polymerase

In the ______ phase of the cell cycle, the cell grows, carries out basic functions, and produces new organelles.

G1

After DNA polymerase adds new nucleotides to replicating DNA, what enzyme forms covalent bonds to join adjacent DNA segments?

Ligase

______ is a specialized type of cell division that produces cells that are genetically different from each other.

Meiosis

What event is occurring along the black arrows in this image?

Metastasis

Select all of the following that can increase the risk of cancer.

UV radiation increased age sexually transmitted viruses smoking

Which of the following best describes the overall process of mitosis?

The type of cell division that separates chromosomes and produces two daughter cells with identical nuclei.

Select all the true statements with respect to benign tumors.

They are usually harmless. They are surrounded by a tough capsule to prevent them from spreading. They grow slowly.

Select all of the following that are true about malignant tumors.

They invade adjacent tissue. They are likely to metastasize.

In animals, an intentional, programmed death of some cells occurs through a process called ______.

apoptosis

Binary fission is a type of ______ seen in prokaryotes, such as archaea and bacteria.

asexual reproduction

Usually, warts and moles are ______ tumors of the skin, meaning they do not invade surrounding tissues or metastasize.

benign

Due to its proofreading accuracy, DNA polymerase incorporates an incorrect nucleotide only about one in a ______ nucleotides.

billion

Select all the examples of cells that divide constantly to produce new cells.

cells at the tips of plant roots bone marrow stem cells

Paired sister chromatids are joined to each other at the

centromere.

The two sister chromatids of a replicated chromosomes attach at a point called the

centromere.

Several internal ______ in the cell cycle ensure that a cell does not enter into the next phase of the cell cycle before completing the previous phase.

checkpoints

A replicated chromosome consists of two attached copies called sister ______

chromatin

Eukaryotic chromosomes consist of _______, which is composed of uncondensed DNA and associated proteins.

chromatin

A single molecule of DNA and its associated proteins is called a

chromosome.

A cell's genetic material is contained in one or more

chromosomes.

In animal cells, the slight indentation around the middle of the cell at the beginning of cytokinesis is called the

cleavage furrow.

What cellular event is occurring in this picture?

cytokinesis

In sexual reproduction, the first cell of the next generation (the zygote) is produced by the process of ______, which is the union of the sex cells.

fertilization

In sexual reproduction, the union of sperm and egg occurs in a process called

fertilization

In sexual reproduction, meiosis results in the production of genetically unique sperm cells and egg cells, which are also called

gametes.

In order for a eukaryotic or prokaryotic cell to divide, it needs to first duplicate its entire ______, which consists of all of its genetic material.

genome

Select all the body and cellular processes that require cell division (mitosis or meiosis) to function.

growth dead cell replacement reproduction

To help fit the very long molecules of DNA that compose a eukaryotic genome into the nucleus of a cell, stretches of DNA are wrapped around proteins called ______.

histones

In a DNA molecule, ______ bonds form between nitrogenous bases, such that A (adenine) pairs with its complement ______, and G (guanine) pairs with its complement ______.

hydrogen; T (thymine); C (cytosine)

In asexual reproduction, the offspring are genetically ________ to each other.

identical

The G1, S, and G2 phases are components of a part of the eukaryotic cell cycle called

interphase.

What enzyme forms covalent bonds between stretches of newly added DNA nucleotides and existing segments of nucleotides during DNA replication?

ligase

When the cell is not dividing, chromatin is ______ so that the DNA is accessible for cell activities.

loosely packed

During DNA replication, which occurs before cell division, the chromatin is ______.

loosely packed and DNA is accessible

What is the key feature that classifies a disease as cancer?

malignant cells

What process gives rise to gametes in humans?

meiosis

A malignant tumor is likely to ______, meaning break away and spread to distant locations.

metastasize

The type of cell division that divides a cell's genetic information into two identical nuclei is called

mitosis

Although they occur rarely, mistakes in DNA replication result in ______, a change in a cell's DNA sequence.

mutation

The term _________ refers to any change in a cell's DNA sequence.

mutation

A DNA molecule consists of two strands of ______ held together in a ______ structure.

nucleotides; double helix

What is the function of centrosomes?

organize the mitotic spindle

The 2 meters of DNA that makes up the human genome is able to fit in one cell because the chromatin is ______.

organized around proteins

Select all of the cancer therapies that are considered to be "blunt tools" because they target rapidly dividing cells, regardless if they are healthy or cancerous.

radiation chemotherapy

Some method of cell division is necessary for every organism to

reproduce

Centromeres attach ______ to each other.

sister chromatids

The _______ consists of microtubule fibers that move the chromosomes during mitosis.

spindle

Select all of the processes involved in asexual reproduction.

splitting of one cell into two cells replication of the genetic material

What type of cells may divide constantly throughout their life?

stem cells

An abnormal mass of tissue that results from the loss of cell cycle control is called a(n)

tumor

Select all of the following that are true about sexual reproduction.

two parents are required offspring are genetically different from their parents offspring are genetically different from each other

Select all of the following that can lead to the formation of a tumor.

uncontrolled cell division lack of programmed cell death

Following mitosis, what process splits the organelles, cytoplasm, duplicated nuclei, and macromolecules into two daughter cells?

Cytokinesis

Select all of the events that occur during prophase.

Mitotic spindle forms. Nucleolus disappears. Nuclear envelope breaks up. Centrosomes migrate to opposite poles.

The ______ describes the series of events that occur in a eukaryotic cell from cell division, including division of the genetic material and the cytoplasm, through the interval of cell activity before the next cell division.

cell cycle

A structure called the ______ is duplicated during S phase and organizes the proteins that will move chromosomes during mitosis.

centrosome

Binary ______ is a type of prokaryotic asexual reproduction in which replicated DNA and other cell parts are distributed into two new daughter cells.

fission

Sperm cells and egg cells are also called

gametes

A cell's ________ is defined as all the cell's genetic material (DNA) and consists of one or more chromosomes containing the DNA.

genome

The stage of mitosis shown in the image is called

metaphase

After DNA replication, chromosomes consist of two

sister chromatids.

What enzyme has proofreading and repair functions during DNA replication?

DNA polymerase

True or false: The daughter cells of mitosis have half as many chromosomes as the parent cell.

FALSE

During the ________ phase of interphase, DNA replication occurs.

S

What cell cycle stage follows G1 but precedes G2?

S

Select all of the following that are part of interphase.

S G2 G1

In sexual reproduction, the sex cells of two different parents fuse to form

a genetically different offspring.

In prokaryotes, DNA is contained in ______, and in eukaryotes, DNA is contained in ______.

a single chromosome; multiple chromosomes

The enzyme called DNA ______ adds new complementary DNA nucleotides to a single-stranded DNA template.

polymerase

The chromosomes condense and become visible under a light microscope during what phase of mitosis?

prophase

The nuclear envelope breaks down during what phase of mitosis?

prophase

In ______, two DNA double helices are synthesized from one DNA double helix molecule when it unwinds and complementary nucleotides are added to the exposed unpaired bases.

DNA replication

What process is illustrated in this picture?

DNA replication

In order for a cell to divide, all of its genetic information has to be duplicated through a process called

DNA replication.

What describes the product of DNA replication?

One strand of a new DNA double helix is newly synthesized and the other strand is from the parent molecule.

True or false: During the G1 phase of interphase, the cell replicates the DNA.

FALSE

True or false: The phase of the cell cycle called interphase is a time of inactivity and rest for the cell after mitosis.

FALSE

A malignant tumor is one that

invades surrounding tissue.

The spindle lines up the chromosomes along the equator of the cell during what phase of mitosis?

metaphase

The mitotic spindle is composed of protein fibers called ______ that coordinate the movements of ______ during mitosis.

microtubules; chromosomes

A type of cell division called _________ divides a eukaryotic cell's genetic information into two identical daughter nuclei.

mitosis

A type of cell division called __________ divides a eukaryotic cell's genetic information into two identical daughter nuclei.

mitosis

Eukaryotic cells produce new cells for growth and repair through a cell division process known as

mitosis.

Eukaryotic cell division is more complicated than binary fission because eukaryotes house the DNA in

multiple chromosomes.

The stage of mitosis shown in the picture is called early

prophase

Select all of the following that are components of chromatin.

proteins for transcription proteins for replication DNA proteins for scaffolding

A replicated chromosome consists of two attached copies called sister

chromatids

The contractile ring of protein filaments at the tip of this arrow forms an indentation called the _______ furrow, which helps divide the cytoplasm of an animal cell in a process called cytokinesis.

cleavage

During a section of the cell cycle collectively called ______, the cell is not dividing, but protein synthesis, cell growth, DNA replication, and basic cell functions are occurring.

interphase