AP BIO 11B,C

The mitotic rate would increase. Without the inhibition of Rb protein, the cells would have a much higher rate of cell division.

The Rb protein prevents mitosis by inhibiting cells from entering S phase. Human papillomavirus (HPV) is thought to inhibit the action of the Rb protein in cervical epithelial cells. What would be the effect of cervical cells being infected with HPV?

oncogene

A gene that causes a cell to become cancerous is called a(n)

proto-oncogene

A normal gene that, if mutated, can lead to cancer is called a(n)

Proto-oncogenes are necessary for normal control of cell division. when these proteins are functioning normally, in the right amounts at the right times, they help properly control cell division and cellular differentiation. But changes in these proteins can result in out-of-control growth.

A proto-oncogene is a normal gene that can change into an oncogene. Oncogenes are potentially lethal genes that can cause cancer. Why do cells continue to maintain proto-oncogenes?

can differentiate into all cell types Embryonic stem cells can differentiate into all cell types. However, adult stem cells are further down the differentiation pathway and are only capable of differentiating into a small number of cell types.

Embryonic stem cells differ from adult stem cells because they __________.

these cells have retained all of their genetic potential The nucleus of the intestinal cell retains all of the genetic information necessary to produce all of the different cells of a tadpole.

In frogs, when the nucleus of an intestinal cell of a tadpole is transferred to an egg whose nucleus has been removed (nuclear transplantation), some of the eggs will develop into normal tadpoles. This demonstrates that _____.

a mutation that causes the proto-oncogene to become overactive

Proto-oncogenes have the potential to become oncogenes. Which of the following is most likely to lead to cancer?

Cloned animals often develop chronic conditions that are usually only associated with old age.

Since the first animal was produced using a fully differentiated cell, a number of observations have been made. Which of the following statements is true in regard to reproductive cloning?

initiates transcription

The p53 protein normally __________.

blastocysts the nucleus in an egg cell is replaced with the nucleus from a donor cell, such as a mammary cell in the case of Dolly the sheep. When it is grown in culture, this cell will develop into a blastocyst, which can be used for therapeutic or reproductive cloning.

Using nuclear transplantation, it is possible to generate __________ for therapeutic uses

adult stem cells

cells that produce a variety of different cells.

tumor-suppressor gene

A(n) -------- is a gene that encodes proteins that inhibit cell division. Such proteins normally help prevent cells from becoming cancerous.

spinal cord injuries If given the right stimuli, stem cells could be differentiated into mature neurons that would replace the damaged ones

Stem cells could be immensely important in the treatment of which of the following conditions in the near future?

Normal controls over cell division have been altered.

Which of the following statements best describes cancer cells?

generation of multiple copies of a proto-oncogene that promotes cell division and inactivation of a tumor-suppressor gene Excess copies of the proto-oncogene could stimulate cell division abnormally, and the inactivation of a tumor-suppressor gene would eliminate a brake on cell division.

Which of the following would be most likely to lead to cancer?

These cells must be able to regenerate various types of cells throughout life.

Why do you think that adult stem cells are found in bone marrow and the lining of the small intestine specifically?

growth factor

a protein that promotes cell division. In excess, such a protein may lead to cancer.