CHAPTER 10 QUESTIONS: Cell Reproduction Cell Cycle →
1. What are the two types of cell division? How do they differ?
a. Which one produces somatic cells?
i. What are somatic cells?
b. Which one produces gametes?
i. What are gametes?
ii. Where are they produced?
2. Which phases make up interphase?
a. What happens in each one?
b. Which phase is the longest?
c. Which phase is the shortest?
d. How long does it take for a mammalian cell to complete the cell cycle? 3. All the DNA in a cell is known as a ________.
4. DNA molecules in a cell are packaged into _____________.
5. What are the two components of a chromosome?
6. How many chromosomes do humans have?
If you want to learn more check out What are the four kinds of love in western tradition?
7. What does DNA look like when it is being replicated?
8. Describe homologous chromosomes.
9. What is ploidy?
a. 1 copy?
b. 2 copies?
10. Sister chromatids are joined by __________ (proteins).
11. T/F: The centrosome is the narrow “waist” of the duplicated chromosomes and the point of closest attachment.
a. If false, what is the actual name of this structure?
12. What are the five stages mitosis, in order?
a. In what stage does the nucleolus begin to disappear?
b. In what stage do the chromosomes line up in the center of the cell? c. In what stage does the cleavage furrow form? Don't forget about the age old question of What are the hormones under the posterior pituitary gland?
i. What is happening when the cleavage furrow forms?
d. In what stage do kinetochores form on the centromeres of sister chromatids? e. The nuclear envelope completely dissipates in what stage?
f. At what point are the sister chromatids pulled across opposite poles by mitotic spindles?
i. How is the cell elongating itself in this stage?
g. Which stage is the shortest stage?
h. When do spindle microtubules first attach to the chromosomes?
i. Name the microtubules that do NOT attach to chromosomes.
i. When is mitosis complete?
j. When do the nucleolus and nuclear envelope reappear?
i. How many cells are present?
ii. What is the ploidy of the cell(s)?
13. Describe the formation of centrosomes.
a. At what stage of interphase do the centrioles duplicate?
b. What is an aster? (Hint: asterisk= star)
c. When do the mitotic spindles begin forming?
14. Explain the two theories for how chromosomes move during anaphase. 15. How does mitosis in a plant cell differ from mitosis in a mammal cell? 16. How do prokaryotes achieve cell division? If you want to learn more check out What are the five stages of platelet activation?
a. What are the steps to this process?
17. What is the function of the cell cycle control system?
a. What are the three checkpoints?
i. What are the reasons for arrest in each?
ii. When does a cell become committed to division?
iii. When does the cell become committed to mitosis?
iv. During which stage of mitosis does the mitotic spindle checkpoint occur? v. In what stage of mitosis is the cell irreversibly committed to completing mitosis?
b. If we were to compare the cell cycle control system to a car, what part would it be? 18. Growth factors (released by certain cells) serve to stimulate ______ __________. 19. What happens in the cell cycle of a cancer cell?
a. Do they need growth factors?
b. What’s the difference between a benign tumor and a malignant tumor? c. What is it called when a normal cell becomes a cancer cell due to contact? d. Why is it extremely dangerous when a cancer metastasizes? Don't forget about the age old question of What is the largest midbrain nucleus?
e. What is the function of protooncogenes?
f. How are oncogenes formed and what are they?
g. What do tumor suppressor genes do?
h. What are the two kinds of exposure that can cause the mutations needed for cancer development?
20. What are the two external controls (physical factors) that check the growth of a cell for optimal density?
a. How do these controls affect cancer cells?
21. Which big macromolecule controls cell division?
CHAPTER 11 QUESTIONS: Meiosis
1. What are the main differences between sexual and asexual reproduction? a. How do the offspring vary? We also discuss several other topics like What are the agents of catastrophe?
2. What is meiosis?
a. What is the main goal of Meiosis I?
b. What is the main goal of Meiosis II?
c. Do haploid AND diploid cells go through meiosis?
3. What are autosomes?
a. What is the chromosome number range?
b. Are sex chromosomes a part of the autosomes?
i. Where do they fall on the number scale of chromosomes?
4. Are there more chromosomes in Meiosis I or Meiosis II? (Remember what the overall goal of meiosis is.)
5. What are the stages of Meiosis I?
a. When do homologous chromosomes undergo synapsis? Don't forget about the age old question of Who is an an italian artist famous for his etchings of rome and of fictitious and atmospheric "prisons"?
b. When does crossingover occur?
i. Where does the crossingover occur?
c. When is ploidy reduced?
d. Are chromosomes or sister chromatids being pulled apart in Anaphase I? e. When do the chromosomes line up?
f. Is there chromosome replication between Meiosis I and Meiosis II? 6. What are the stages of Meiosis II?
a. When do the spindles begin forming?
b. When do the spindles separate the chromatids to the opposite poles of the cell? c. When do the spindles disassemble?
d. At what stage does cytokinesis occur?
e. When do the chromatids line up in the center of the cell?
f. When does the nuclear envelope reform?
7. How is meiosis unique from mitosis in terms of:
a. Genetic diversity?
b. The metaphase stage?
c. Diploid and haploid cells?
d. Homologous chromosomes?
8. What happens during crossingover?
a. What are the new chromosomes called?
b. How many crossingover events typically occur per chromosome pair? 9. How does fertilization work?
a. Is it random?
10. What is the difference between dizygotic twins and monozygotic twins? a. Which pair is fraternal?
b. Which pair is identical?
c. Which is more likely to happen?
11. How does variability act as “insurance” in case of environmental change? 12. A ___________ is the number and appearance of chromosomes in the nucleus of a eukaryotic cell.
13. A ______ _______ is the generationtogeneration sequence of stages in the reproductive history of an organism.
14. What produces genetic variability?
CHAPTER 8: Photosynthesis
∙ Autotrophs – make their own food
o Producers – feed most of the living world
∙ Photoautotrophs – use energy of sunlight to make organic molecules from H₂O and CO₂ o Plants
o Some protists, archaea, bacteria (plants, algae, cyanobacteria)
∙ Heterotrophs – obtain food from other organisms
o Depend on photoautotrophs for food and O₂
o Cellular respiration backwards
o 6CO₂ + H₂O + light energy C → ₆H₁₂O₆ + 6O₂ + 6H₂O
o Endergonic process
Absorbs energy; anabolic; not spontaneous; “uphill”
∙ Pigments are substances that absorb visible light
∙ Calvin Cycle
o 1) Carbon fixation
o 2) Reduction
o 3) Regeneration of the CO₂ acceptor (RuBP: ribulose biphosphate)
∙ ATP + NADPH (light reactions in thylakoid) NADP → ⁺ + ADP + P (ᵢ Calvin Cycle in stroma) light reactions Calvin Cycle → →
o Photosynthesis occurs in chloroplasts of autotrophic eukaryotes
o Photosynthesis occurs in the mesophyll (middlelayer) of leaves of plants Stomata – small, regulated openings that control gas exchange of CO₂ and O₂; conserve water by closing
o Thylakoid space: high H⁺ concentration
Thylakoid membrane has lipid bilayer
Chlorophyll embedded in thylakoid membrane
A stack of thylakoids = granum
Discshaped, membranebound structure inside a chloroplast
o Stroma space: low H⁺ concentration
Liquidfilled space surrounding the granum; “bed”
∙ Energy of sunlight is used to energize electrons
∙ Glyceraldehyde3phosphate (GA3P) sugar molecules →
∙ Lightdependent reactions – energy from sunlight is absorbed by chlorophyll chemical → energy
o Take place in thylakoid
∙ Lightindependent reactions – chemical energy from lightdependent reactions sugar → molecules from carbon dioxide
o Take place in the stroma
1. Where in a plant does photosynthesis occur?
2. Which –trophs tend to be producers?
3. Which –trophs tend to be consumers?
4. What is the equation for photosynthesis?
5. What are the products of photosynthesis?
6. What is the name of the substance that absorbs visible light?
7. What are the three phases of the Calvin cycle?
8. Photosynthesis converts solar energy into __________ energy.
9. What are the differences between lightdependent and lightindependent reactions? 10. Where does photosynthesis occur in a plant?
11. What are the differences between the thylakoid space and the stroma? 12. What is the function of the stomata/stoma?
CHAPTER 9: Cell Communication
∙ Forms of chemical signaling
o Short distance
Autocrine – a cell targets itself
Signaling across gap junctions – a cell targets a cell connected by gap junctions
Paracrine – a cell targets a nearby cell
o Long distance
Endocrine – a cell targets a distant cell through the bloodstream
∙ Right receptor right message →
o Specificity in signal receipt
∙ Sending the signal
o Direct contact
o Important during embryonic development and the immune response
o Extracellular signals – molecules secreted from a signaling cell into the extracellular space
o Long Distance
Hormones reach virtually all body cells but are only bound by some cells Electrical transmission down nerve cells
∙ THE THREE STAGES OF CELL SIGNALING
Ligand – signal molecule that binds a specific receptor
∙ Makes sure the right activities happen at the right time in the right
∙ Neurotransmitters – chemical ligands
Occurs on the membrane
Relay molecules: mostly proteins; relay signal from receptor to response Signal transduced into different form (shape change in a protein)
Occurs in the cytoplasm
o Response (activation of cellular response)
Occurs in the nucleus or cytoplasm
Activates gene expression
Not always as simple as “on” and “off”
∙ Amplification of signal amplification of response →
o Same signaling molecule leads to different responses
∙ Termination of the signal
∙ Two Types of Cell Receptors
o Membrane bound cell receptors
Gprotein coupled receptors
Receptor tyrosine kinases
Ion channel receptors
o Intracellular receptors
Found in cytoplasm or nucleus
Ligands are either hydrophobic or very small
∙ Benefit of multiple steps
o Signal amplification – binding of one or a few neurotransmitter molecules can enable the entry of millions of ions; a few molecules send signal to many molecules to activate
o Coordination and regulation of cellular response
∙ Protein Phosphorylation and Dephosphorylation
o Regulate protein activity
o Protein kinases – phosphates from ATP to protein
o Protein phosphatases – quickly remove phosphates from proteins
o Phosphorylation cascade – most relay molecules in signal transduction pathways are protein kinases
∙ Small Molecules and Ions as Second Messengers
o Second messengers – small, nonprotein, watersoluble molecules or ions that spread throughout a cell by diffusion
Ex: Cyclic AMP and calcium ions
∙ Cell Communication in Unicellular Organisms: Directional Growth o Exchange of mating factors mating new a/ cell → → ɑ
∙ Apoptosis – programmed cell death
o Broken, blobby remains are digested by specialized scavenger cells
o Internal signals can result from damaged DNA or excessive misfolded protein o Essential for normal development
∙ Drug – a biological substance that produces an effect on an organism’s body when taken o Beneficial (ex: aspirin) or toxic (ex: heroin)
o Synthetic or nonsynthetic
1. What are the forms of chemical signaling?
a. Which ones are short distance?
2. What is an extracellular signal?
3. What are the three stages of cell signaling?
a. What happens in each one?
b. Where does each one occur?
c. Which one(s) use ligands?
d. Which one uses relay molecules?
e. Where does the response typically occur?
4. How does specificity affect cell response?
5. What are the benefits of a multistep cell communication process? 6. Name the differences between protein kinases and protein phosphatases. a. Which one is associated with phosphorylation?
7. What do second messengers do?
8. Explain the cell communication process in a unicellular organism. 9. What is apoptosis?
a. What is its function?
b. What role does it play in development?