Chapter 10 Test

What is the name of the proteins that regulate the cell cycle? _____________________________

Cyclins

When the cytoplasm of an animal cell divides at the end of mitosis, the process is called ___________________

Cytokinesis

T/F As a cell's size increases, its ratio of surface area to volume increases

False

T/F Most of a cell's growth takes place during the G2 phase of the cell cycle

False

Cancer is a disorder in which some cells have lost the ability to control their __________________

Growth rate/cell division

Surface Area to Volume Ratio

Imagine a cell shaped like a cube. As the length of the sides of a cube increases, its volume increases faster than its surface area, decreasing the ratio of surface area to volume. If a cell gets too large, the surface area of the cell is not large enough to get enough oxygen and nutrients in and waste out.

HOW IS THE CELL CYCLE REGULATED? INTERNAL VS. EXTERNAL REGULATION. DESCRIBE THE ROLE OF CYCLINS IN THE CELL CYCLE

Internal regulators are proteins that respond to events inside a cell. They allow the cell cycle to proceed only once certain processes have happened inside the cell. External regulators are proteins that respond to events outside the cell. They direct cells to speed up or slow down the cell cycle. Cyclins are a family of proteins that regulate the timing of the cell cycle in eukaryotic cells.

Regulation

Internal regulators are proteins that respond to events inside a cell. They allow the cell cycle to proceed only once certain processes have happened inside the cell. External regulators are proteins that respond to events outside the cell. They direct cells to speed up or slow down the cell cycle. Growth factors are external regulators that stimulate the growth and division of cells. They are important during embryonic development and wound healing.

What is the role of the spindle fibers during mitosis? ______________________________

It helps to separate sister chromatids

During which phase(s) of the cell cycle are chromosomes visible?

M Phase

During which phase of mitosis do the chromosomes line up in the middle of the dividing cell? ____________

Metaphase

The two main stages of cell division are called ___________________ and ________________________

Mitosis and cytokinesis

WHAT ARE DIFFERENCES IN MITOSIS BETWEEN PLANTS AND ANIMALS?

Plants lack centrioles. The spindle apparatus is synthesized by microtubule organizing centers which are not visible. Cytokinesis in animal cell proceed through production of a cleavage furrow. Plants cells are rigid and cannot form a cleavage furrow. They divide by the formation of a cell plate, which is an expanding partition that grows outward from the interior of the cell until it reaches the cell membrane.

DNA is replicated during which part of the cell cycle? ________________________________

S Phase

A cell that has 5 chromosomes in the G1 phase will have _____________ chromatids in the G2 phase

Ten

What happens when cells come in contact with other cells?

They stop dividing

G1 Phase

cells increase in size and synthesize new proteins and organelles

Totipotent

cells that are able to develop into any type of cell found in the body (including the cells that make up the extraembryonic membrane and placenta)

G2 Phase

many of the organelles and molecules required for cell division are produced

S Phase

new DNA is synthesized when the chromosomes are replicated

Cyclin

one of a family of proteins that regulates the cell cycle in eukaryotic cells

Growth Factor

one of a group of external regulatory proteins that stimulate the growth and division of cells

Sister Chromatid

one of two identical "sister" parts of a duplicated chromosome

Interphase

period of the cell cycle between cell divisions

Anaphase

phase of mitosis in which the chromosomes separate and move to opposite ends of the cell

Differentiation

process in which cells become specialized in structure and function

Apoptosis

process of programmed cell death

Asexual Reproduction

process of reproduction involving a single parent that results in offspring that are genetically identical to the parent

Cell Cycle

series of events in which a cell grows, prepares for division, and divides to form two daughter cells

Metastasis

the spread of cancer cells

What is the purpose of apoptosis?

Apoptosis is a process of programmed cell death. Apoptosis plays a role in development by shaping the structure of tissues and organs in plants and animals. For example, the foot of a mouse is shaped the way it is partly because the toes undergo apoptosis during tissue development.

A form of reproduction that involves only one parent cell is called __________________________

Asexual Reproduction

T/F If it takes a cell one hour to undergo mitosis, the least amount of that time would be spent in prophase

False

T/F The sequence of phases of mitosis is prophase, anaphase, metaphase, telophase, followed by interphase, which is actually the time between mitotic divisions

False-PMAT

Surface Area

Food, oxygen, and water enter a cell through the cell membrane. Waste products leave in the same way. The rate at which this exchange takes place depends on the surface area of a cell.

During normal mitotic cell division, a parent cell having four chromosomes will produce two daughter cells, each containing __________________chromosomes

Four

Cell Division

The process by which a cell divides into two new daughter cells

T/F If cytoplasm from a cell that is undergoing mitosis is injected into a cell that is in interphase, the second cell will enter mitosis

True

T/F Interphase typically takes much longer than mitosis and cytokinesis

True

T/F Normal human body cells have 46 chromosomes

True

T/F The number of chromosomes differs in different organisms, but is the same in virtually all the normal cells of an individual organism

True

T/F There are some cells in your body that will never divide

True-Nerve cells and some muscle cells

What are stem cells? What are some of the possible benefits associated with stem cell research?

Unspecialized (generic) cells that have the potential to differentiate into a wide variety of cell types. "Differentiation" Each tissue in your body came from stem cells Stem cells have the potential to grow new tissue Your body may not be able to produce the right cells to fix an injury - nerve cells Implanting stem cells may be able to help

The rate at which wastes are produced by a cell depends on the cell's a. Environment b. Volume c. Surface area d. Ratio of surface area to volume

Volume

Cell Plate

a double membrane across the midline of a dividing plant cell, between which the new cell wall forms during cytokinesis

Spindle Fibers (Microtubules)

a fanlike microtubule structure that helps separate the chromatids

Tumor

a mass of rapidly dividing cells that can damage surrounding tissue

Histones

any of a group of basic proteins found in chromatin

Pluripotent

can't form a whole organism, but can become many types of tissues

Cancer

disorder in which some of the body cells lose the ability to control growth

Cytokinesis

division of the cytoplasm to form two separate daughter cells

Binary fission

type of asexual reproduction in which an organism replicates its DNA and divides in half, producing two identical daughter cells

Stem Cells

unspecialized cell that can give rise to or more types of specialized cells

DNA/genes

genetic material that organisms inherit from their parents/sequence of DNA that codes for a protein and thus determines a trait; factor that is passed from parent to offspring

M Phase

in eukaryotes, cell division occurs in two stages: mitosis and cytokinesis. Mitosis is the division of the cell nucleus. Cytokinesis is the division of the cytoplasm.

Centromere

region of a chromosome where the two sister chromatids attach

Centriole/Centrosome

structure in an animal cell that helps to organize cell division

Chromatin

substance found in eukaryotic chromosomes that consists of DNA tightly coiled around histones

Volume

the amount of space that a substance or object occupies, or that is enclosed within a container, especially when great

Mitosis

the division of the cell nucleus

Prophase

the first phase of mitosis, the duplicated chromosome condenses and becomes visible. The centrioles move to opposite sides of nucleus and help organize the spindle. The spindle forms and DNA strands attach at a point called their centromere. The nucleolus disappears and nuclear envelope breaks down

Telophase

the fourth and final phase of mitosis, the chromosomes spread out into a tangle of chromatin. A nuclear envelope re-forms around each cluster of chromosomes. The spindle breaks apart, and a nucleolus becomes visible in each daughter nucleus.

Metaphase

the second phase of mitosis, the centromeres of the duplicated chromosomes line up across the center of the cell. The spindle fibers connect the centromere of each chromosome to the two poles of the spindle

Single Chromosome

threadlike structure of DNA and protein that contains genetic information; in eukaryotes are found in the nucleus; in prokaryotes they are found in the cytoplasm