Biology ยท Science General
Cell Biology and Structure
3,062 Questions
Cell biology focuses on the structure and function of cellular organelles. Key topics include cellular respiration, DNA inheritance, and energy production. These fundamental biology concepts are crucial for medical entrance and state service examinations.
Cell organelles functionsCellular respiration sitesDNA and ribosomesAnimal cell structurePlant cell components
Cell Biology and Structure Questions
Which of the following is NOT a type of skin cell?
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Keratinocytes
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Melanocytes
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Langerhans cells
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Adipocytes
D
Correct answer
Explanation
Adipocytes are fat cells and are not found in the skin.
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They are detected by receptors on the surface of cells
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They are absorbed through the skin
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They are inhaled
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All of the above
D
Correct answer
Explanation
Pheromones can be detected by receptors on the surface of cells, absorbed through the skin, or inhaled. Once a pheromone is detected, it can trigger a variety of responses, such as attraction, aggression, or fear.
Where does transcription occur?
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In the nucleus
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In the cytoplasm
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In the mitochondria
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In the endoplasmic reticulum
A
Correct answer
Explanation
Transcription occurs in the nucleus of eukaryotic cells. During transcription, genetic information from DNA is copied into a complementary strand of mRNA.
Which type of microscope is commonly used to study the structure of biological samples at the cellular and subcellular level?
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Compound microscope
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Electron microscope
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Scanning tunneling microscope
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Atomic force microscope
A
Correct answer
Explanation
Compound microscopes, which utilize multiple lenses to achieve high magnification, are commonly used in biological research to study the structure of cells and their components.
Which mathematical model is used to describe the spread of cancer cells through the bloodstream?
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Metastasis model
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Invasion model
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Angiogenesis model
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Proliferation model
A
Correct answer
Explanation
The metastasis model is a mathematical equation that describes the spread of cancer cells through the bloodstream. It takes into account the rate of cancer cell shedding from the primary tumor, the rate of cancer cell survival in the bloodstream, and the rate of cancer cell colonization at secondary sites.
Which mathematical model is used to describe the spread of cancer cells through the lymphatic system?
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Metastasis model
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Invasion model
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Angiogenesis model
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Lymphatic model
D
Correct answer
Explanation
The lymphatic model is a mathematical equation that describes the spread of cancer cells through the lymphatic system. It takes into account the rate of cancer cell shedding from the primary tumor, the rate of cancer cell survival in the lymphatic system, and the rate of cancer cell colonization at secondary sites.
Which of the following is a theory of aging that focuses on the role of cellular senescence?
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The free radical theory
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The telomere theory
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The genetic theory
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The cellular senescence theory
D
Correct answer
Explanation
The cellular senescence theory proposes that aging is caused by the accumulation of senescent cells in the body. Senescent cells are cells that have stopped dividing and are no longer functional. They can release harmful substances that can damage other cells and tissues.
Which of the following is a theory of aging that focuses on the role of stem cell depletion?
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The free radical theory
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The telomere theory
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The genetic theory
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The stem cell depletion theory
D
Correct answer
Explanation
The stem cell depletion theory proposes that aging is caused by a decline in the number and function of stem cells. Stem cells are cells that can divide and differentiate into other types of cells. A decline in stem cell function can lead to a decline in the ability of tissues to repair themselves.
Which of the following is a type of prostate cancer that is characterized by slow growth?
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Adenocarcinoma
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Squamous cell carcinoma
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Transitional cell carcinoma
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Small cell carcinoma
A
Correct answer
Explanation
Adenocarcinoma is the most common type of prostate cancer and is characterized by slow growth.
Which type of cell-cell communication involves direct physical contact between cells?
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Autocrine signaling
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Paracrine signaling
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Endocrine signaling
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Juxtacrine signaling
D
Correct answer
Explanation
Juxtacrine signaling occurs when cells communicate through direct physical contact, exchanging signals via cell surface molecules.
Which signaling pathway is commonly associated with cell growth and proliferation?
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cAMP signaling pathway
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MAP kinase signaling pathway
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JAK-STAT signaling pathway
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TGF-beta signaling pathway
B
Correct answer
Explanation
The MAP kinase signaling pathway is known for its involvement in cell growth, proliferation, and differentiation.
Where does the electron transport chain take place?
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Cytoplasm
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Mitochondrial matrix
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Inner mitochondrial membrane
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Outer mitochondrial membrane
C
Correct answer
Explanation
The electron transport chain is located on the inner mitochondrial membrane, which is folded into cristae to increase the surface area for efficient electron transfer.
Which cellular structure is responsible for protein synthesis?
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Nucleus
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Ribosome
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Mitochondrion
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Endoplasmic reticulum
B
Correct answer
Explanation
Ribosomes are cellular structures composed of RNA and protein. They are responsible for protein synthesis by assembling amino acids in the correct order specified by the mRNA.
Which type of stem cell is found in adult tissues?
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Embryonic stem cells
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Induced pluripotent stem cells
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Adult stem cells
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Mesenchymal stem cells
C
Correct answer
Explanation
Adult stem cells are found in various tissues throughout the body and have the ability to differentiate into specific cell types within that tissue.
Which of the following is a type of cancer that originates in the cells of the breast?
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Lung cancer
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Breast cancer
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Leukemia
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Colon cancer
B
Correct answer
Explanation
Breast cancer is a type of cancer that originates in the cells of the breast.