Ch 20 HW ans key

Ch 20 HW ans key - function 3 Apoptosis is programmed cell...

Info iconThis preview shows pages 1–2. Sign up to view the full content.

View Full Document Right Arrow Icon
Ch. 20 HW answer key MCQ: 1) C 2) A 3) D 4) A 5) B T/F: 1) F 2) T 3) F 4) F 5) T Match A with B: 1) d 2) e 3) f 4) b 5) g 6) a 7) c SQ: 1) Discussion question #4 from the text book. Answer at page A-43 2) Proto-oncogenes are responsible for basic cellular functions in normal cells. They encode transcription factors that stimulate expression of other genes; they also encode signal transduction molecules that stimulate cell division and cell- cycle regulators. When normal cells are not dividing, the proto-oncogenes are repressed. Oncogenes are the cancer-causing genes. These are the proto-oncogenes that have undergone a gain-of-function alteration. This alteration may arise from a mutation in the proto-oncogene that encodes for a protein with abnormal activity or it can arise from overexpression of proto-oncogenes that are not repressed when necessary or by translocation which results in a hybrid gene with an abnormal
Background image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full Document Right Arrow Icon
Background image of page 2
This is the end of the preview. Sign up to access the rest of the document.

Unformatted text preview: function. 3) Apoptosis is programmed cell death in which normal cells with irreparable DNA damage are programmed to die. Apoptosis is genetically controlled by specific proteins like Bcl-2 and BAX. The relative concentration of these two proteins is crucial in apoptosis. In normal cells, Bcl-2 and BAX are in equal proportions and bind to form inactive heterodimers. Excess of Bcl-2 results in formation of Bcl-2 homodimer which prevents apoptosis whereas excess of BAX forms BAX homodimers which promote apoptosis. In normal cells, p53 induces transcription of BAX and inhibits that of Bcl-2, leading to cell death. In cancer cells, defective p53 fails to induce the apoptotic pathway leading to continuous cell growth. Problem: Discussion question #6 from the text book. Answer at page A-43...
View Full Document

{[ snackBarMessage ]}

Page1 / 2

Ch 20 HW ans key - function 3 Apoptosis is programmed cell...

This preview shows document pages 1 - 2. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online