Exam 3 study guide

Study Guide - Smart Notes

Tailored notes based on your materials, expanded with key definitions, examples, and context.

Q1. What is apoptosis?

Background

Topic: Programmed Cell Death

This question tests your understanding of apoptosis, a fundamental biological process important for development and homeostasis in multicellular organisms.

Key Terms:

Apoptosis: Programmed cell death, a controlled process by which cells self-destruct when they are no longer needed or are a threat to the organism.

Step-by-Step Guidance

Recall that apoptosis is a type of cell death distinct from necrosis (which is uncontrolled cell death due to injury).
Think about why apoptosis is important in development (e.g., shaping organs, removing unneeded cells) and in preventing diseases like cancer.
Consider the cellular features of apoptosis, such as DNA fragmentation, cell shrinkage, and membrane blebbing.

Try describing apoptosis in your own words before checking the answer!

Q2. Which gene is the master regulator of apoptosis? How does it work?

Background

Topic: Genetic Regulation of Apoptosis

This question focuses on the key gene that controls apoptosis and its mechanism of action.

Key Terms:

Master regulator gene: A gene that controls a critical cellular process.
p53: A well-known tumor suppressor gene involved in apoptosis regulation.

Step-by-Step Guidance

Identify the gene most commonly referred to as the master regulator of apoptosis (hint: it is often mutated in cancers).
Think about how this gene senses DNA damage or cellular stress and what it does in response.
Consider the downstream effects: Does it activate other proteins or pathways to initiate apoptosis?

Try to recall the gene and its function before revealing the answer!

Q3. What are the characteristics of a dying cell?

Background

Topic: Cellular Morphology During Apoptosis

This question asks you to recognize the physical and biochemical changes that occur in a cell undergoing apoptosis.

Key Terms:

Cell shrinkage, chromatin condensation, membrane blebbing, DNA fragmentation.

Step-by-Step Guidance

List the morphological changes that are hallmarks of apoptosis.
Think about how these changes differ from necrosis (uncontrolled cell death).
Consider the fate of cellular components during apoptosis (e.g., formation of apoptotic bodies).

Try listing the characteristics before checking the answer!

Q4. What are caspases? What do they do?

Background

Topic: Enzymes in Apoptosis

This question tests your knowledge of the molecular machinery that executes apoptosis.

Key Terms:

Caspases: Cysteine-aspartic proteases, a family of enzymes that play essential roles in apoptosis.

Step-by-Step Guidance

Recall what type of enzyme caspases are and what their substrates are.
Think about the cascade mechanism: initiator caspases activate executioner caspases.
Consider the cellular targets of caspases and the outcomes of their activity.

Try explaining the role of caspases before revealing the answer!

Q5. What are oncogenes? What are proto-oncogenes?

Background

Topic: Cancer Genetics

This question is about genes involved in the regulation of cell growth and how their alteration can lead to cancer.

Key Terms:

Oncogenes: Mutated or overactive forms of genes that promote cell division and can lead to cancer.
Proto-oncogenes: Normal genes that, when mutated, become oncogenes.

Step-by-Step Guidance

Define proto-oncogenes and their normal function in the cell.
Explain how a proto-oncogene can become an oncogene (e.g., mutation, amplification).
Describe the consequences of oncogene activation for the cell cycle and cancer development.

Try defining these terms before checking the answer!

Q6. How do proto-oncogenes convert to oncogenes?

Background

Topic: Mechanisms of Cancer Development

This question focuses on the molecular changes that turn normal growth-promoting genes into cancer-causing genes.

Key Terms:

Mutation, gene amplification, chromosomal translocation.

Step-by-Step Guidance

List the main mechanisms by which proto-oncogenes can be converted to oncogenes.
For each mechanism, briefly describe how it leads to increased or unregulated gene activity.
Think about examples of each mechanism (e.g., point mutation, gene duplication, fusion genes).

Try to recall the mechanisms before revealing the answer!

Q7. What are tumor-suppressing genes? What do they do?

Background

Topic: Cancer Genetics

This question is about genes that prevent uncontrolled cell growth and how their loss can contribute to cancer.

Key Terms:

Tumor suppressor genes: Genes that inhibit cell division or promote apoptosis.

Step-by-Step Guidance

Define tumor suppressor genes and their normal role in the cell cycle.
Explain what happens when these genes are mutated or inactivated.
Consider examples of tumor suppressor genes (e.g., p53, Rb).

Try defining tumor suppressor genes before checking the answer!

Q1. What are the functions of cell division?

Background

Topic: Cell Division

This question tests your understanding of why cells divide in multicellular organisms.

Key Terms:

Growth, repair, reproduction.

Step-by-Step Guidance

List the main purposes of cell division in multicellular organisms.
Think about examples: development from a fertilized egg, healing wounds, producing gametes.
Consider the difference between mitosis (for growth/repair) and meiosis (for reproduction).

Try listing the functions before checking the answer!

Q2. What are the parts of the cell cycle? What happens in each phase?

Background

Topic: Cell Cycle Phases

This question is about the sequence of events in the life of a cell and what occurs in each stage.

Key Terms:

Interphase (G1, S, G2), Mitotic phase (M phase).

Step-by-Step Guidance

List the main phases of the cell cycle in order.
For each phase, briefly describe the key events (e.g., DNA replication in S phase).
Distinguish between interphase and mitosis.

Try outlining the phases and their events before checking the answer!

Q3. What is mitosis? How is it different from cytokinesis?

Background

Topic: Cell Division Processes

This question tests your understanding of the difference between nuclear division and cytoplasmic division.

Key Terms:

Mitosis: Division of the nucleus.
Cytokinesis: Division of the cytoplasm.

Step-by-Step Guidance

Define mitosis and its purpose in the cell cycle.
Define cytokinesis and how it follows mitosis.
Compare and contrast the two processes.

Try explaining the difference before checking the answer!

Q4. What are kinetochores? What is their role in cell division?

Background

Topic: Chromosome Movement in Mitosis

This question is about the structures that attach chromosomes to the spindle apparatus during cell division.

Key Terms:

Kinetochores: Protein complexes on chromosomes where spindle fibers attach.

Step-by-Step Guidance

Define what a kinetochore is and where it is located on the chromosome.
Describe how kinetochores interact with spindle microtubules during mitosis.
Explain the importance of kinetochores for accurate chromosome segregation.

Try describing kinetochores and their function before checking the answer!

Q5. What are centrosomes?

Background

Topic: Cell Division Structures

This question focuses on the organelles that organize microtubules during cell division.

Key Terms:

Centrosome: Microtubule-organizing center in animal cells.

Step-by-Step Guidance

Define what a centrosome is and its components (e.g., centrioles in animal cells).
Describe the role of centrosomes in organizing the mitotic spindle.
Consider how centrosomes duplicate and move during cell division.

Try defining centrosomes before checking the answer!

Q6. Describe figure 12.9 (Pac-man mechanism)

Background

Topic: Chromosome Movement Mechanisms

This question refers to a textbook figure illustrating how chromosomes move during anaphase.

Key Terms:

Pac-man mechanism: Model where kinetochores "chew" their way along microtubules as they depolymerize.

Step-by-Step Guidance

Recall what happens to microtubules during anaphase (shortening at kinetochore ends).
Describe how the Pac-man mechanism explains chromosome movement toward the poles.
Think about the role of motor proteins at the kinetochore.

Try describing the mechanism before checking the answer!

Q7. What is cytokinesis? What is a difference in cytokinesis between plant cells and animal cells?

Background

Topic: Cytoplasmic Division

This question is about the final step of cell division and how it differs in plants and animals.

Key Terms:

Cytokinesis: Division of the cytoplasm.
Cell plate (plants), cleavage furrow (animals).

Step-by-Step Guidance

Define cytokinesis and its timing relative to mitosis.
Describe how cytokinesis occurs in animal cells (formation of a cleavage furrow).
Describe how cytokinesis occurs in plant cells (formation of a cell plate).

Try explaining the difference before checking the answer!

Q8. What are the checkpoints in the cell cycle control system? What happens at each checkpoint?

Background

Topic: Cell Cycle Regulation

This question is about the control points that regulate progression through the cell cycle.

Key Terms:

G1, G2, M checkpoints.

Step-by-Step Guidance

List the main checkpoints in the cell cycle.
For each checkpoint, describe what the cell checks for (e.g., DNA damage, proper chromosome attachment).
Explain the consequences if a cell does not pass a checkpoint.

Try outlining the checkpoints and their roles before checking the answer!

Q9. What are the regulatory proteins that are involved in cell cycle control? What do they do? Be specific.

Background

Topic: Cell Cycle Regulation

This question focuses on the proteins that regulate cell cycle progression.

Key Terms:

Cyclins, cyclin-dependent kinases (Cdks).

Step-by-Step Guidance

Identify the main classes of regulatory proteins in the cell cycle.
Describe how cyclins and Cdks interact to control cell cycle transitions.
Give examples of specific cyclin-Cdk complexes and their roles.

Try naming and describing these proteins before checking the answer!

Q10. Define: density-dependent inhibition and anchorage dependence

Background

Topic: Cell Growth Regulation

This question is about mechanisms that regulate when cells stop dividing.

Key Terms:

Density-dependent inhibition: Cells stop dividing when crowded.
Anchorage dependence: Cells must be attached to a substrate to divide.

Step-by-Step Guidance

Define density-dependent inhibition and give an example.
Define anchorage dependence and explain its importance in tissue structure.
Consider how cancer cells may lose these properties.

Try defining these terms before checking the answer!

Q1. What is meiosis?

Background

Topic: Sexual Reproduction

This question tests your understanding of the process that produces gametes.

Key Terms:

Meiosis: Cell division that reduces chromosome number by half.

Step-by-Step Guidance

Define meiosis and its purpose in sexually reproducing organisms.
Contrast meiosis with mitosis in terms of chromosome number and genetic variation.
Think about the types of cells that undergo meiosis.

Try defining meiosis before checking the answer!

Q2. Where does this occur?

Background

Topic: Location of Meiosis

This question is about the tissues or organs where meiosis takes place.

Key Terms:

Gonads: Ovaries and testes.

Step-by-Step Guidance

Recall the organs in animals where gametes are produced.
Consider the equivalent structures in plants (e.g., anthers, ovules).
Think about the cell types that undergo meiosis in these organs.

Try recalling the locations before checking the answer!

Q3. Define: gametes, somatic cells, autosomes, diploid cell, haploid cell.

Background

Topic: Chromosome Terminology

This question tests your understanding of key terms related to chromosomes and cell types.

Key Terms:

Gametes: Reproductive cells (sperm, egg).
Somatic cells: All body cells except gametes.
Autosomes: Non-sex chromosomes.
Diploid: Two sets of chromosomes (2n).
Haploid: One set of chromosomes (n).

Step-by-Step Guidance

Define each term clearly and concisely.
Give an example for each term (e.g., human sperm is a gamete and haploid).
Distinguish between diploid and haploid cells in terms of chromosome number.

Try defining each term before checking the answer!

Q4. What are homologous chromosomes? Are they the same? Draw and label a pair of duplicated homologous chromosomes. You may need to identify: centromere, sister chromatids, non-sister chromatids, homologous chromosomes

Background

Topic: Chromosome Structure

This question is about the similarities and differences between homologous chromosomes and their structure after DNA replication.

Key Terms:

Homologous chromosomes: Chromosome pairs with the same genes but possibly different alleles.
Sister chromatids: Identical copies formed by DNA replication.
Centromere: Region where chromatids are joined.
Non-sister chromatids: Chromatids from homologous chromosomes.

Step-by-Step Guidance

Define homologous chromosomes and explain how they are similar and different.
Describe what happens to homologous chromosomes during DNA replication.
Label the centromere, sister chromatids, and non-sister chromatids on a diagram (try drawing this yourself!).

Try drawing and labeling before checking the answer!

Q5. What happens during each stage of meiosis?

Background

Topic: Stages of Meiosis

This question is about the sequence of events in meiosis I and II.

Key Terms:

Prophase I, Metaphase I, Anaphase I, Telophase I, Prophase II, etc.

Step-by-Step Guidance

List the stages of meiosis I and II in order.
For each stage, briefly describe the key events (e.g., crossing over in Prophase I).
Note the differences between meiosis I and II.

Try outlining the stages and events before checking the answer!

Q6. What are the ways by which meiosis enhances genetic variation? Make sure you know what happens and at what stage this event happens.

Background

Topic: Genetic Variation in Meiosis

This question is about the mechanisms that increase genetic diversity during meiosis.

Key Terms:

Crossing over, independent assortment, random fertilization.

Step-by-Step Guidance

List the main sources of genetic variation in meiosis.
For each, describe what happens and at which stage (e.g., crossing over in Prophase I).
Explain how these mechanisms contribute to genetic diversity in offspring.

Try identifying the mechanisms and their stages before checking the answer!

Q7. Comparison between meiosis 1 and meiosis 2

Background

Topic: Meiosis Phases Comparison

This question asks you to compare the two divisions in meiosis.

Key Terms:

Meiosis I: Reductional division.
Meiosis II: Equational division.

Step-by-Step Guidance

Describe what separates in each division (homologous chromosomes in I, sister chromatids in II).
Compare the chromosome number before and after each division.
Note any unique events in meiosis I (e.g., crossing over, synapsis).

Try outlining the differences before checking the answer!

Q8. Comparison between meiosis 2 and mitosis

Background

Topic: Cell Division Comparison

This question is about the similarities and differences between meiosis II and mitosis.

Key Terms:

Meiosis II: Division of haploid cells.
Mitosis: Division of diploid or haploid cells (depending on organism).

Step-by-Step Guidance

Compare the processes: both separate sister chromatids.
Contrast the starting chromosome number and genetic diversity of the products.
Note any differences in the context of the organism's life cycle.

Try comparing the two processes before checking the answer!

Q1. How is oogenesis different from spermatogenesis in terms of the final products?

Background

Topic: Gametogenesis

This question is about the differences in the gametes produced by males and females.

Key Terms:

Oogenesis: Egg production.
Spermatogenesis: Sperm production.

Step-by-Step Guidance

Recall how many functional gametes are produced from one precursor cell in each process.
Consider the size and resource content of the gametes produced.
Think about the presence of polar bodies in oogenesis.

Try outlining the differences before checking the answer!

Q2. How is oogenesis different from spermatogenesis in terms of the overall process?

Background

Topic: Gametogenesis

This question is about the timing and regulation of gamete formation in males and females.

Key Terms:

Continuous vs. cyclic production, timing of meiosis, arrest stages.

Step-by-Step Guidance

Describe when and how often each process occurs (e.g., continuous in males, cyclic in females).
Explain the timing of meiotic divisions in oogenesis (e.g., arrest at certain stages).
Compare the regulatory mechanisms controlling each process.