Chapter 3 Flashcards
1
Q
Basic chromosomes structure
A
- Chromatin (unwound DNA)
- DNA
- Chromosomes
👉🏻we have 46 double stranded chromos
2
Q
Centromere
A
Connects two chromatids
3
Q
Kintochore
A
Fibers
4
Q
Telomere
A
Tips
5
Q
Chromatids
A
Two single strands
6
Q
How long does it take the cell cycle
A
24 hrs
7
Q
G1 (Gap 1)
A
Cell grows, normal metabolic processes take place
8
Q
S
A
Replication
9
Q
G2 (gap 2)
A
Cell prepares for mitosis
10
Q
Mitosis
A
Separation of the chromosomes (karyokinesis)
11
Q
Cytokinesis
A
Cytoplasm seperates
12
Q
Order of the cell cycle
A
- Interphase
- Prophase
- Metaphase
- Anaphase
- Telophase
13
Q
Interphase
A
- DNA replication
- Chromatin
- Cell growth
- Nucleus represent
14
Q
Prophase
A
- Nucleus disappears
- Nuclear membrane disappears
- Double stranded chromosome
- Centrioles migrate to poles
- Asters and spindles form
15
Q
Metaphase
A
- Double stranded chromosomes line up at the equator
16
Q
Anaphase
A
- Single stranded chromosomes move to poles
- Cell plate formation (plant) furrowing in animal cells
- Centromeres split
17
Q
Telophase
A
- Two brand new daughter cells
- Nucleus reappears
- Astros and spindles disappear
- Cytokinesis ( plant produce a cell plate)
18
Q
Does a zygote undergo mitosis or meiosis
A
Mitosis
19
Q
Reasons why cells divide instead of grow
A
- The larger a cell becomes, the more demands the cell places on its DNA
- A larger cell is less efficient in moving nutrients and waste materials across the cell membrane
20
Q
Cell size limitations
A
- Surface area to volume ratio
a) key factor in cell size
b) cell stays small
21
Q
Diffusion limits cell size
A
- Movement from higher concentration to lower concentration
- Larger the distance, slower the diffusion rate
- A cell 20cm would require months for nutrients to get to the center
22
Q
DNA limits cell size
A
- Larger cells need more DNA
- Needs more of everything
👉🏻most cells just have one nucleus
23
Q
What does the DNA check to assure the cell divides properly
A
The DNA is checked to make sure it has replicated properly
24
Q
Cyclins
A
Proteins that regulate the timing of the cell cycle
25
Internal regulatory proteins
All the cell cycle to proceed after certain events have occurs
26
External regulatory proteins
Growth factors stimulate the cell cycle. some cause it to slow down or stop
27
Why division?
1. Growth
a) stem cells
2. Repair
3. Reproduction
a) Asexual (genetically identical)
b) sexual
28
Apoptosis
A cell may die by accident due to damage or injury, or a cell may actually be programmed to die
29
Benign
Not cancerous
30
Malignant
Cancerous
31
What do malignant cells do
1. Kills healthy tissue
2. Block blood vessels
3. Prevent organs from working properly
4. Divide uncontrollably
32
Mutations caused by...
1. Radiation
2. Smoking/drugs
3. Pollutants
4. Chemicals
5. Viruses
6. Defective genes
33
Division in cancer cells
Cancer cells will continue to divide with mutations
34
Cancer- Mitosis out of control!
1. Cells lose their ability to control growth
2. Don't respond to signals that regulate growth
3. Divide uncontrollably
35
Dif in dividing in normal cells and cancer cells
When normal cells feel something is wrong they can blow themselves up, while cancer cells continue to divide
36
Metastasis
Cancer moves
37
Telomeres in cancer cells
They stay long
38
Chemical signals in cancer cells
Cancer cells ignore the chemical signals that start and stop the cell cycle
39
Radiation
Interferes with the copying of DNA
40
Chemotherapy
The use of chemicals to kill cancer cells that are weaker
41
Removal
Cancerous tumors
42
Tumor suppressor genes
Limit cell growth
43
Oncogenes
Promoting the growth of cells
44
How does BRCA function normally in cells
Help ensure the stability of the cells genetic material and help prevent uncontrolled cell growth
45
Do mutated BRCA genes indicate you will have cancer
No they just increase the risk
