Question 1: What is the role of powerful microscopes in studying cells?
Answer 1: Microscopes, such as the laser scanning microscope, are essential for observing and studying cells, providing detailed images that wouldn't be possible with the naked eye.
Question 2: What paved the way for the discovery of cells and cellular research?
Answer 2: Advancements in microscopes, which allowed scientists to observe individual cells and microorganisms that were previously invisible
Question 3: What are the three types of microscopes mentioned?
Answer 3:
- Simple Microscope: (e.g., magnifying glass) - 10-500x magnification.
- Compound Light Microscope: Common in labs - 400-2,500x magnification.
- Electron Microscope: Uses electrons, up to 1 million times magnification.
Question 4: State the three components of the Cell Theory.
Answer 4:
- A cell is the basic unit of structure and function for all living things.
- All organisms are made of cells.
- All cells come from preexisting cells.
Question 5: What is the significance of Modern Cell Theory additions?
Answer 5: Modern Cell Theory adds that cells contain hereditary information passed during cell division and that all cells are similar in composition and metabolic activities.
Question 6: Why are cells considered the basic units of structure and function for living organisms?
Answer 6: Cells are responsible for every structure within an organism's body and every function it performs, from repair and growth to transporting gases and nutrients.
Question 7: Differentiate between unicellular and multicellular organisms.
Answer 7:
- Unicellular Organisms: Made of a single cell (e.g., bacteria).
- Multicellular Organisms: Composed of many cells (e.g., humans), performing more complex functions.
Question 8: What technological advancements led to the modification of the original Cell Theory?
Answer 8: Advancements in microscopes, especially electron microscopes, provided more detailed insights, leading to the modification and expansion of the original Cell Theory.
Question 9: What did the creation of synthetic cells by J. Craig Venter's team involve?
Answer 9: They created a synthetic cell using a digital genetic code, assembling a chromosome in yeast, and transplanting it into a bacterial host cell, resulting in a new bacterial species.
Question 10: What does the term "Modern Cell Theory" encompass?
Answer 10: Modern Cell Theory adds that cells contain hereditary information passed during cell division and that all cells are similar in composition and metabolic activities, based on research with advanced microscopes.
What is the focus of today's science lesson on cells?
The lesson focuses on prokaryotic and eukaryotic cells, exploring their internal structures.
According to Robert Hooke, who named cells, what did he observe that led to their discovery?
He observed little spaces, or cells, in the magnified cork from an oak tree.
List the common internal structures shared by all cells.
DNA, ribosomes, cytoplasm, and a cell membrane.
What distinguishes prokaryotic cells from eukaryotic cells in terms of structure and organization?
Prokaryotic cells are unicellular, lack a true nucleus, and membrane-bound organelles. Eukaryotic cells are multicellular, have a true nucleus, and membrane-bound organelles.
Explain the concept of endosymbiotic theory in the context of cells.
Endosymbiotic theory proposes that mitochondria and chloroplasts in eukaryotic cells originated from symbiotic relationships with prokaryotic cells, providing an explanation for their similarities.
What is phagocytosis, and how does it contribute to the evolution of eukaryotic cells?
Phagocytosis is the cellular process of engulfing solid particles, forming internal vacuoles. This process is believed to have led to the incorporation of aerobic bacteria, evolving into mitochondria.
How does endosymbiotic theory impact our understanding of the relationship between mitochondria, chloroplasts, and eukaryotic cells?
It suggests that mitochondria and chloroplasts were once independent prokaryotic cells that formed a symbiotic relationship, contributing to the evolution of eukaryotic cells.
What evidence supports endosymbiotic theory, and how does it relate to DNA in mitochondria?
Evidence includes independent growth, similar size to prokaryotic cells, and having their own DNA. Mitochondrial DNA, maternally inherited, supports the theory and has applications in forensics.
How does the discovery of mitochondria and DNA within it impact fields like forensics and genetics?
Mitochondrial DNA typing in forensics uses the DNA from mitochondria to link individuals, aiding in solving crimes, identifying victims, and finding missing persons. It also provides insights into genetic inheritance and ancestry tracing.
Question: Provide an example from the warm-up that illustrates a reaction to external conditions.
Answer: Two individuals reacting to external conditions – one shivering in the rain (cold) and one sweating after a run (hot).
Question: What is the purpose of shivering mentioned in Section 1?
Answer: Shivering is a way for the body to heat itself up when feeling chilly.
Question: What temperature does the body aim to maintain, as mentioned in Section 1?
Answer: Around 98.6 degrees Fahrenheit.
Question: List two learning objectives from Section 3.
Answer:
- Explain how cells maintain homeostasis.
- Differentiate between diffusion, osmosis, passive transport, and active transport.
Question: What is the importance of homeostasis mentioned in Section 3?
Answer: Homeostasis is crucial for living organisms to function properly and survive.
Question: What does the cell membrane control, according to Instruction Section 1?
Answer: The cell membrane controls what goes into and what comes out of the cell.
Question: Why is understanding homeostasis important for comprehending cell functions?
Answer: Cells perform functions to maintain internal stability, and understanding homeostasis is crucial to comprehend these functions.
Question: Define homeostasis as mentioned in Instruction Section 2.
Answer: Homeostasis is maintaining stable internal conditions despite changing external factors.
Question: What are some physiological features mentioned in Instruction Section 2 that contribute to homeostasis?
Answer: Adjustment of oxygen, carbon dioxide, pH, nutrient and waste concentrations, salt, pressure, and extracellular fluid volume.
Question: Describe passive transport as discussed in Instruction Section 7.
Answer: Passive transport is the movement of particles across the cell membrane from an area of higher concentration to an area of lower concentration without using energy.
Question: What is facilitated diffusion, and what assists in this process?
-
- Answer: Facilitated diffusion is assisted by carrier protein molecules, and it occurs without using energy.
Question: What are the three processes mentioned in Section 10 for maintaining homeostasis?
Answer: Active transport, passive transport, and diffusion.
Question: Why is the ability of a cell to maintain homeostasis essential?
Answer: It allows the cell to function at its finest and contributes to the overall survival of the organism.
Question: Provide an example of an animal adapting to extreme cold mentioned in Section 11.
Answer: Polar bears.
Question: How do kangaroo rats survive extreme heat, as discussed in Section 11?
Answer: They find shade underground and sleep during the day to avoid extreme temperatures.
Question: What does the graph in Section 14 illustrate about the paramecium in a hypertonic solution?
Answer: There is an inverse proportion between salt concentration and contractions per minute.
Question: How does the paramecium maintain homeostasis in a hypertonic solution?
Answer: The contractile vacuole pumps water out of the cell.
Question: What is the common theme in Summary Section 1?
Answer: External conditions impact individuals' homeostasis, linking to cellular adaptation.
Question: How do cells compensate for external conditions, as mentioned in Summary Section 1?
Answer: Cells adapt and maintain internal stability similar to polar bears and kangaroo rats.
Question: What is the key function of the cell membrane, according to Summary Section 2?
Answer: The cell membrane controls what goes into and comes out of the cell.
Question: Why are examples of polar bears and kangaroo rats provided in Summary Section 2?
Answer: To emphasize the importance of homeostasis in various organisms, highlighting adaptations to extreme conditions.
Question: What is mitosis, and in which organisms does it occur?
Answer: Mitosis is the process cells undergo for reproduction, occurring in multicellular organisms like animals, plants, fungi, and protists.
Question: Name examples of eukaryotes and their characteristics.
Answer: Eukaryotes include animals, plants, fungi, mushrooms, and protists. They have a true nucleus and membrane-bound organelles.
Question: What are the phases of the cell cycle mentioned in Section 2?
Answer: The cell cycle has two stages: interphase (including G1, S, and G2) and mitosis.
Question: What is the purpose of interphase in the cell cycle?
Answer: Interphase is a growth period where the cell's DNA is duplicated, preparing for cell division.
Question: List the stages of mitosis in order (use the abbreviation PMAT).
Answer: Prophase, Metaphase, Anaphase, Telophase (PMAT).
Question: Describe the key events in Prophase.
Answer: Chromatin coils into visible chromosomes, and the nucleus, nucleolus, and nuclear membrane disappear.
Question: What happens during Metaphase in mitosis?
Answer: Doubled chromosomes attach to spindle fibers and align across the center of the spindle.
Question: Explain the process of Anaphase in mitosis.
Answer: Centromeres split, sister chromatids are pulled to opposite ends of the cell.
Question: What is the final stage of mitosis, and what occurs during this stage?
Answer: Telophase is the final stage where sister chromatids separate, and nuclear envelope reappears.
Question: Why is mitosis important for living organisms?
Answer: Mitosis is crucial for growth, repair, and reproduction of cells, ensuring the survival of organisms.
Question: How do tissue cultures contribute to the study of mitosis and cancer cells?
Answer: Tissue cultures help study mitosis and cancer cells by demonstrating how cancer cells lack contact inhibition, allowing researchers to test medications before patient use.
Question: What is the main objective of analyzing new technologies and experiments in mitosis studies?
Answer: The objective is to understand how new technologies and experiments affect previous scientific explanations, as demonstrated through tissue cultures and cancer cell studies.
Question: What is the primary purpose of meiosis?
Answer: Meiosis produces cells that are different from the original cell, allowing for genetic variation.
Question: How many cellular divisions occur during meiosis, and what is the result?
Answer: Meiosis involves two cellular divisions, producing four haploid cells with half the number of chromosomes as the parent cell.
Question: Define "diploid" and "haploid" in the context of meiosis.
Answer: A diploid cell has two sets of chromosomes, while a haploid cell has half the number of chromosomes as the parent cell.
Question: What is the role of crossing over in meiosis?
Answer: Crossing over, occurring during prophase 1, involves the exchange of genetic material between nonsister chromatids, increasing genetic diversity.
Question: Explain the significance of independent assortment in meiosis.
Answer: Independent assortment, during metaphase 1, results in random alignment of chromosome pairs, contributing to new combinations of alleles and increased genetic variation.
Question: How does meiosis contribute to sexual reproduction?
Answer: Meiosis creates gametes (sperm and eggs), and when these gametes fuse during fertilization, they form an offspring with a diploid number of chromosomes, introducing genetic diversity.
Question: Who is Gregor Mendel, and what did he contribute to the understanding of genetics?
Answer: Gregor Mendel studied heredity using pea plants, discovering that traits are passed independently from parent to offspring, laying the foundation for understanding genetic variation.
Question: What is the significance of genetic recombination in meiosis?
Answer: Genetic recombination, achieved through crossing over, independent assortment, and fertilization, ensures that organisms are not identical to their parents, promoting genetic diversity.
Question: How does genetic variation contribute to the survival of organisms?
Answer: Genetic variation, achieved through meiosis, provides raw materials for natural selection, allowing the most suited organisms to survive, reproduce, and pass on beneficial traits.
Question: Summarize the key concepts of meiosis in one sentence.
Answer: Meiosis involves two divisions, producing four haploid cells, and contributes to genetic variation through processes like crossing over and independent assortment.
Question: What is reproduction?
Answer: Reproduction involves making new cells or organisms in living organisms.
Question: Why is reproduction more than just the offspring of small animals and humans?
Answer: Because bacteria and all cells in living organisms go through various forms of reproduction.
Question: What does the baby in the warm-up represent in terms of reproduction?
Answer: The baby represents both the reproduction of an organism through fertilization and the reproduction of cells as it started from one cell and grew to millions.
Question: How does asexual reproduction differ from sexual reproduction in terms of genetic variation?
- Answer: Asexual reproduction results in identical DNA, while sexual reproduction introduces genetic variation.
Question: What are gametes, and in which type of reproduction are they involved?
Answer: Gametes are male and female sex cells involved in sexual reproduction.
Question: How does mitosis contribute to asexual reproduction?
Answer: Mitosis is the process in eukaryotes where a single cell divides into two identical cells, contributing to asexual reproduction.
Question: What are the four stages of cell division in mitosis, and what do they stand for?
Answer: PMAT - Prophase, Metaphase, Anaphase, Telophase.
Question: Why is meiosis necessary for sexual reproduction?
Answer: Meiosis reduces chromosome number by half, creating gametes with genetic variation for sexual reproduction
Question: What is the significance of crossing over in meiosis?
Answer: Crossing over in prophase I of meiosis results in a mix-up of genetic traits, providing genetic variation.
Question: What are the advantages of asexual reproduction?
Answer: Rapid reproduction, no need for a mate, and cloning for agricultural purposes.
Question: What are the disadvantages of asexual reproduction?
Answer: Accumulation of mutations, lack of genetic variation, and susceptibility to negative consequences.
Question: Why is sexual reproduction considered slower than asexual reproduction?
Answer: It involves finding a suitable mate and a longer process of cell division through meiosis.
Question: What was the conclusion from the study on snails regarding asexual reproduction?
Answer: Asexual reproduction led to faster accumulation of mutations compared to sexual reproduction.
Question: Why is genetic variation important in sexual reproduction?
Answer: Genetic variation allows for adaptation to changing environments and reduces the rate of mutations.
Question: Summarize the differences between asexual and sexual reproduction.
Answer: Differences include organisms involved, cell division process, number of divisions, presence of gametes, DNA replication, genetic variation, speed, and complexity.
Question: Who introduces the concept of cell differentiation and specialization in the warm-up?
Answer: Mr. Morales.
Question: Why do differences in structures exist among cells and tissues in living organisms?
Answer: Differences in structures allow cells and tissues to perform specific functions.
Question: What is the initial stage of human development after the joining of gametes?
Answer: Embryo.
Question: What is the process of developing specialized cells from stem cells called?
Answer: Differentiation.
Question: What are the objectives mentioned for the end of the lesson?
Answer: Explain the role of differentiation, describe specialized cells, analyze external condition effects.
Question: What are the examples of specialized cells discussed in this section?
Answer: Blood cells, muscle cells, neurons, and epithelial cells.
Question: What are the characteristics of epithelial cells mentioned in the lecture?
Answer: Transport, protect, absorb, secrete, and provide sensory signals.
Question: What is the state of maintaining a stable internal environment despite changing external conditions called?
Answer: Homeostasis.
Question: How do cells communicate to maintain balance in the body?
Answer: Through chemical messages.
Question: What is the overarching theme of the summary?
Answer: Recap of cell differentiation, specialization, and the importance of maintaining internal balance.