Cell Reproduction Flashcards
What is cellular reproduction?
The process by which cells duplicate and divide to create new cells.
How do humans go from a single cell to trillions of cells?
Through cellular reproduction over 10 months.
What is the significance of cellular reproduction in adulthood?
It replaces damaged tissues and heals injuries.
What are the two main types of cellular reproduction?
Asexual reproduction (e.g., binary fission) and sexual reproduction (involving sperm and egg).
According to the cell theory, where do all cells originate from?
All cells originate from preexisting cells.
What is the purpose of cellular reproduction?
Generating new cells and organisms.
What are the two main phases of cellular reproduction?
Growth (duplication of organelles and DNA) and cell division (distribution of contents to daughter cells).
Why is regulation crucial in cellular reproduction?
To prevent uncontrolled cellular reproduction, which can have serious consequences.
What is DNA replication, and when does it occur in the cell cycle?
DNA replication is the process of copying DNA, and it occurs during cell division.
What are chromosomes, and how do they aid in cell division?
Chromosomes are structures in which DNA is packaged, and they help distribute DNA to daughter cells.
What are histones?
Proteins that help package DNA into chromatin.
How does chromatin differ from chromosomes?
Chromatin is a less condensed, thread-like structure of DNA and associated proteins, whereas chromosomes are highly condensed and visible structures.
What is the role of proteins and enzymes in DNA replication and chromosome packaging?
They are responsible for DNA replication and condensing DNA into chromosomes.
What are the key events in cellular reproduction, and in what order do they occur?
Duplication of cell contents and cell division, occurring in an orderly sequence within the cell cycle.
What are the four phases of the cell cycle?
G1, S, G2, and M, with interphase consisting of G1, S, and G2.
What is the role of the G1 phase in the cell cycle?
It is the phase before DNA replication, where the cell decides whether to continue with the cell cycle.
What happens during the S phase of the cell cycle?
DNA synthesis takes place, converting each chromosome from one chromatid to two sister chromatids joined at the centromere.
What is the M phase in the cell cycle, and what occurs during it?
The M phase includes mitosis, where the duplicated nuclear contents are evenly distributed to daughter cells.
How is the cell cycle controlled, and what analogy is often used to explain it?
The cell cycle is controlled by a system that ensures the orderly progression of phases.
What are cell cycle checkpoints, and what is their purpose?
Checkpoints are control points in the cell cycle that ensure that phases occur in order and only proceed when the previous phase is successfully completed.
What is the significance of the G1 checkpoint?
Passing the G1 checkpoint commits the cell to divide, while not passing it can lead the cell to enter G0. It checks for proper growth signals and DNA integrity.
What role does the p53 protein play in the cell cycle?
The p53 protein can stop the cell cycle and initiate DNA repair or apoptosis if DNA is damaged.
What is the M checkpoint’s purpose in the cell cycle?
The M checkpoint occurs during the mitotic stage and ensures that chromosomes are properly attached to the spindle for accurate distribution to daughter cells.
What is apoptosis?
Apoptosis is a programmed cell death involving a series of events leading to cell destruction.
What are caspases, and how do they relate to apoptosis?
Caspases are enzymes involved in apoptosis. They are typically inhibited but can be unleashed by signals like shortened telomeres or DNA damage.
How does apoptosis balance the number of cells in the body?
While cell division increases the number of cells, apoptosis decreases cell numbers, eliminating abnormal or potentially cancerous cells.
What is the significance of apoptosis in the development of an organism?
Apoptosis is necessary for shaping the organism by eliminating certain cells, such as the disappearance of a tadpole’s tail during metamorphosis.
What is cancer, and what causes it?
Cancer is a disease resulting from a lack of control in the cell cycle, often caused by mutations in genes.
What are proto-oncogenes and tumor suppressor genes, and how do they relate to cancer?
Proto-oncogenes promote the cell cycle, while tumor suppressor genes inhibit it. Mutations in these genes can lead to cancer.
How do genetic changes like telomere shortening and telomerase relate to cancer?
Telomere shortening can inhibit cell division, while telomerase can prevent this inhibition, contributing to cancer.
What are some examples of genes associated with cancer susceptibility?
Genes like BRCA1, BRCA2, RB, and RET are associated with increased cancer risk.
How are cancers classified based on their tissue of origin?
Cancers can be classified as carcinomas, sarcomas, or leukemias based on their tissue of origin.
What are some characteristics of cancer cells, and what is metastasis?
Cancer cells invade nearby tissues and can metastasize, forming new tumors in distant locations.
What are common treatments for cancer, and how do they work?
Treatments include surgery, radiation therapy, chemotherapy, and immunotherapy. They aim to remove tumors or disrupt cancer cell replication.
How can cancer risk be reduced through protective behaviors and dietary guidelines?
Protecting behaviors include avoiding smoking and excessive sun exposure. Dietary guidelines suggest consuming foods rich in vitamins A and C and avoiding certain processed and salt-cured foods.
What is the purpose of cellular reproduction in humans?
a. To maintain cell size
b. To generate new cells and organisms
c. To produce energy
d. To eliminate damaged cells
Answer: b. To generate new cells and organisms
Which type of reproduction involves the formation of offspring with genetic variation?
a. Asexual reproduction
b. Binary fission
c. Sexual reproduction
d. Mitosis
Answer: c. Sexual reproduction
According to the cell theory, where do all cells originate from?
a. Preexisting cells
b. Inorganic materials
c. Viruses
d. Spontaneous generation
Answer: a. Preexisting cells
What is the role of histones in chromosome structure?
a. DNA replication
b. DNA packaging
c. DNA synthesis
d. DNA repair
Answer: b. DNA packaging
What is the main difference between chromatin and chromosomes?
a. Chromatin is found in prokaryotic cells, while chromosomes are in eukaryotic cells.
b. Chromatin is a more condensed form of DNA than chromosomes.
c. Chromatin is thread-like, while chromosomes are highly condensed and visible.
d. Chromatin is only present during mitosis.
Answer: c. Chromatin is thread-like, while chromosomes are highly condensed and visible.
What is the primary purpose of interphase in the cell cycle?
a. Cell division
b. Growth and organelle duplication
c. DNA synthesis
d. Cytokinesis
Answer: b. Growth and organelle duplication
During which phase of the cell cycle does DNA synthesis occur?
a. G1 phase
b. G2 phase
c. M phase
d. S phase
Answer: d. S phase
What analogy is often used to explain the cell cycle control system?
a. Traffic lights
b. Washing machine
c. Bicycle gears
d. Computer software
Answer: b. Washing machine
What is the role of the G1 checkpoint in the cell cycle?
a. It initiates DNA replication.
b. It decides whether the cell should continue with the cell cycle.
c. It separates sister chromatids.
d. It ensures proper chromosome attachment to the spindle.
Answer: b. It decides whether the cell should continue with the cell cycle.
What is apoptosis?
a. Uncontrolled cell division
b. A programmed cell death process
c. The replication of DNA
d. A phase of the cell cycle
Answer: b. A programmed cell death process
What is the role of caspases in apoptosis?
a. They promote cell division.
b. They inhibit DNA replication.
c. They initiate the destruction of a cell.
d. They repair damaged DNA.
Answer: c. They initiate the destruction of a cell.
What is the primary cause of cancer?
a. Bacterial infections
b. Viral infections
c. Lack of control in the cell cycle
d. Exposure to X-rays
Answer: c. Lack of control in the cell cycle
Which type of genes, when mutated, can promote uncontrolled cell division and cancer?
a. Tumor suppressor genes
b. DNA repair genes
c. Histone genes
d. Centrosome genes
Answer: a. Tumor suppressor genes
What is the primary goal of cancer treatment?
a. To eliminate all cancer cells in the body
b. To promote rapid cell division
c. To control cell cycle checkpoints
d. To remove tumors or disrupt cancer cell replication
Answer: d. To remove tumors or disrupt cancer cell replication
What are carcinomas?
a. Cancers originating from muscle or connective tissue
b. Cancers affecting the blood and blood-forming tissues
c. Cancers arising from epithelial tissue lining organs
d. Cancers resulting from genetic mutations
Answer: c. Cancers arising from epithelial tissue lining organs
What is the role of the G2 checkpoint in the cell cycle?
a. To initiate DNA synthesis
b. To decide whether the cell should enter G1 phase
c. To ensure DNA replication has occurred successfully
d. To separate sister chromatids
Answer: c. To ensure DNA replication has occurred successfully
How do external signals, such as growth factors, influence the cell cycle?
a. They inhibit cell division.
b. They promote apoptosis.
c. They stimulate cell cycle progression.
d. They cause DNA damage.
Answer: c. They stimulate cell cycle progression.
Which of the following factors can increase the risk of skin cancer, including melanoma?
a. Consuming too many leafy vegetables
b. Excessive sun exposure
c. Regular exercise
d. Drinking plenty of water
Answer: b. Excessive sun exposure
What is the primary goal of immunotherapy in cancer treatment?
a. To promote angiogenesis
b. To remove tumors surgically
c. To stimulate the patient’s immune system to target cancer cells
d. To repair damaged DNA
Answer: c. To stimulate the patient’s immune system to target cancer cells
What is the primary purpose of apoptosis in the body?
a. To eliminate healthy cells
b. To promote uncontrolled cell division
c. To balance the number of cells and eliminate abnormal or potentially cancerous cells
d. To trigger DNA replication
Answer: c. To balance the number of cells and eliminate abnormal or potentially cancerous cells
