Mastering Biology Questions 8, 11

which causes colon cancer?

Fat

Which of these acts as a second messenger?

cyclic amp

Integrins are integral membrane proteins. They are often attached to ________.

cytoskeletal proteins and molecules of the extracellular matrix.

The primary role of _____ is to bind animal cells together.

desomosomes

DNA is composed of four nucleosides: adenosine, cytidine, thymidine, and guanosine. If scientists introduced radioactive thymidine into the growth medium of the cells, it would be incorporated into the DNA molecule ________.

during dna replication

Calcium ions that act as second messengers are stored in _____

endoplasmic reticulum

Which event does not take place before the start of mitosis?

nuclear envelope disintegrates

If cancer cells detach from neighboring cells, what is a likely outcome of this event?

Loss of desmosomes

Plasmodesmata are cell-cell junctions that are found between _____.

adjacent plant cells

During which substage of mitosis do sister chromatids break apart and start moving to opposite poles of the cell?

Anaphase

What role does a transcription factor play in a signal transduction pathway?

By binding to DNA it triggers the transcription of a specific gene.

True or false? Mitosis takes place during M phase, which is the longest phase of the cell cycle.

False

aid in the coordination of the activities of adjacent animal cells.

Gap junctions

_____ catalyzes the production of _____, which then opens an ion channel that releases _____ into the cell's cytoplasm.

Phospholipase C ... IP3 .... Ca2+

What is a major difference in the extracellular matrix (ECM) between plant and animal cells?

Plant ECM is primarily carbohydrate in nature, whereas animal ECM is largely protein based.

Regulatory proteins that serve to prevent a cell from entering the S phase under conditions of DNA damage are also known as ________.

Regulatory proteins that serve to prevent a cell from entering the S phase under conditions of DNA damage are also known as ________.

Which stage of mitosis is characterized by the disintegration of mitotic spindles and the formation of two new nuclear membranes?

Telophase

What determines the primary structure of an RNA molecule?

What determines the primary structure of an RNA molecule?

All of the following can be proteins found in the extracellular matrix of animal cells except ________.

actin

Which of these is NOT a carcinogen?

all of the above, fat, smoking, testerone, viruses, uv light

A protein kinase activating many other protein kinases is an example of _____

amplification

Centromeres divide and sister chromatids become full-fledged chromosomes during _____.

anaphase

For a tissue or an organ to function as a unit, ________.

cell-cell communication

The microtubular organizing center found in animal cells is an identifiable structure present during all phases of the cell cycle. Specifically, it is known as which of the following?

centrosome

Nucleoli are present during _____.

interphase

To which part of the centromere do mitotic spindle fibers attach during prometaphase?

kinetocore

Pemphigus vulgaris is an autoimmune disorder in humans in which antibodies are produced against the cadherins of desmosomes. The blistering of the skin and mucous membranes characteristic of this disorder is probably a result of _____.

loss in cell-cell adhesion

Acetylcholine is a neurotransmitter that binds to receptors on skeletal muscle cells. The receptor-signal complex brings about a series of events that result in contraction of skeletal muscle. Venom from black widow spiders causes an explosive release of acetylcholine. What would that do to its victims?

muscles wouldn't relax

Spindle fibers attach to kinetochores during _____.

prometaphase

Chromosomes become visible during _____.

prophase

A signal transduction pathway is initiated when a _____ binds to a receptor.

signal molecule

Hormones function as ________.

signal molecules

Which term describes two recently replicated DNA strands that are joined together just before cell division?

sister chromatids

Cytokinesis often, but not always, accompanies ___

telophase

Cytokinesis often, but not always, accompanies _____.

telophase

Treating dissociated cells with certain antibodies makes the cells unable to reaggregate. Why?

the antibodies bind to cell adhesion proteins called cadherins.

A parent cell divides to form two genetically identical daughter cells in the process of mitosis. For mitosis to take place ________.

the parent cell must replicate its entire genome prior to mitosis.

Which of these cell junctions form a barrier to the passage of materials?

tight junctions

During prophase a homologous pair of chromosomes consists of _____.

two chormosomes and four chromatids

Why are tight junctions found in only certain types of tissues, while desmosomes are found in a wide array of cells?

water-tight epthilia