14. Selective Topic

Question 1

Progeria

Answer 1

A premature aging disorder caused by mutations in the LMNA gene producing defective lamin A (progerin).

Question 2

Lamin A gene

Answer 2

A gene encoding lamin A, a nuclear envelope protein; mutations cause nuclear instability and premature aging.

Question 3

Werner syndrome

Answer 3

A genetic disorder with early aging due to WRN helicase mutation, impairing DNA repair and replication.

Question 4

Free Radical Theory

Answer 4

Aging results from cumulative cellular damage caused by reactive oxygen species (ROS).

Question 5

Genetic Clock Theory (Telomere Theory)

Answer 5

Aging is driven by progressive telomere shortening that limits cell divisions.

Question 6

Accumulative-waste Theory

Answer 6

Aging results from accumulation of metabolic waste and damaged macromolecules in cells.

Question 7

Acidification Theory

Answer 7

Aging occurs due to gradual intracellular acidification that disrupts metabolism.

Question 8

Neuroendocrine Theory

Answer 8

Aging is caused by dysregulation of the hypothalamus and hormonal signaling systems over time.

Question 9

Mutation Theory

Answer 9

Aging results from accumulation of DNA mutations impairing cellular function.

Question 10

Autoimmune Theory

Answer 10

Aging is driven by immune system decline and production of autoantibodies attacking self-tissues.

Question 11

Cross-Binding Theory

Answer 11

Aging is caused by cross-linking of proteins (e.g., collagen), reducing tissue elasticity and function.

Question 12

Stem Cell Theory

Answer 12

Aging is due to depletion or functional decline of adult stem cells.

Question 13

Evolutionary Theories

Answer 13

Aging occurs because natural selection weakens with age, allowing harmful late-acting mutations.

Question 15

Light microscope

Answer 15

Instrument using visible light and optical lenses to magnify specimens up to ~1000×.

Question 16

Fluorescence microscope

Answer 16

Microscope that uses fluorochromes to visualize labeled structures with high sensitivity.

Question 17

Confocal microscope

Answer 17

Laser-based microscope producing high-resolution optical sections and 3D images.

Question 18

Transmission electron microscopy (TEM)

Answer 18

Electron microscope transmitting electrons through thin samples for internal ultrastructure imaging.

Question 19

Scanning electron microscopy (SEM)

Answer 19

Electron microscope using surface-scattered electrons to generate detailed 3D surface images.

Question 20

Phase contrast microscope

Answer 20

Microscope enhancing contrast of transparent specimens without staining by converting phase shifts to brightness.

Question 21

Objective lens

Answer 21

The main magnifying lens located close to the specimen.

Question 22

Eyepiece (ocular)

Answer 22

Lens through which the observer views the image, providing additional magnification.

Question 23

Micrometer screw

Answer 23

Fine-focus adjustment knob for precise focusing.

Question 24

Macrometer screw

Answer 24

Coarse-focus knob used for large adjustments in focusing.

Question 25

Diaphragm

Answer 25

Device controlling the amount of light passing through the specimen.

Question 26

Condenser

Answer 26

Optical component that concentrates light on the specimen for better resolution.

Question 27

Wavelength of light

Answer 27

The distance between two light wave peaks; shorter wavelength increases resolution.

Question 28

Numerical aperture

Answer 28

A measure of lens light-gathering ability; higher NA improves resolution.

Question 29

Resolution

Answer 29

The ability to distinguish two points as separate.

Question 30

Fluorochrome

Answer 30

A fluorescent dye that emits light when excited by specific wavelengths.

Question 31

Fluorescent proteins

Answer 31

Naturally fluorescent proteins (e.g., GFP) used to label cellular structures.

Question 32

Fusion proteins

Answer 32

Proteins genetically linked to a tag (e.g., GFP) for visualization or purification.

Question 34

DNA isolation

Answer 34

Process of extracting pure DNA from cells using lysis, precipitation, and purification.

Question 35

Protein isolation

Answer 35

Extraction and purification of proteins from biological samples using biochemical methods.

Question 36

Centrifugation

Answer 36

Technique using centrifugal force to separate components based on density.

Question 37

Ultracentrifugation

Answer 37

High-speed centrifugation capable of separating macromolecules, organelles, and ribosomes.

Question 38

Affinity chromatography

Answer 38

Separation technique using specific binding interactions (antibody–antigen, ligand–receptor).

Question 39

Gel filtration

Answer 39

Chromatography that separates molecules by size using porous beads.

Question 41

Sex-determination system

Answer 41

Biological mechanism determining whether an organism develops as male or female.

Question 42

XX/XY system

Answer 42

Mammalian system where XX = female and XY = male.

Question 43

SRY gene

Answer 43

Y-chromosome gene encoding Testis Determining Factor (TDF), initiating male development.

Question 44

TDF

Answer 44

Protein encoded by SRY that triggers testis formation.

Question 45

Swyer syndrome

Answer 45

XY individuals with nonfunctional SRY leading to female external phenotype and gonadal dysgenesis.

Question 46

Testosterone

Answer 46

Primary male sex hormone produced by testes, essential for male differentiation.

Question 47

'Z' gene

Answer 47

General term for sex-determination genes on Z chromosome in some species.

Question 48

XX/X0 system

Answer 48

Sex system where XX = female, X0 = male (e.g., insects).

Question 49

ZZ/ZW system

Answer 49

System where ZZ = male and ZW = female (birds, reptiles, amphibians).

Question 50

DMRT1 gene

Answer 50

Z-linked gene essential for testis development in the ZZ/ZW system.

Question 51

Haplodiploidy

Answer 51

Sex system where males are haploid (unfertilized eggs) and females are diploid (fertilized eggs).

Question 52

Non-genetic sex determination

Answer 52

Sex determined by environmental factors (temperature, pH, social cues).

Question 53

Parasexuality

Answer 53

Genetic recombination without meiosis, seen in fungi and some microbes.

Question 55

Biodiversity

Answer 55

The variety of life at genetic, species, and ecosystem levels.

Question 56

Red Book

Answer 56

IUCN Red List documenting endangered and threatened species.

Question 57

Global warming

Answer 57

Long-term increase in Earth's average temperature due to greenhouse gases.

Question 58

Kyoto Climate Change Conference

Answer 58

1997 conference where the Kyoto Protocol established emission reduction targets.

Question 59

Ozone depletion

Answer 59

Reduction of stratospheric ozone caused by CFCs, increasing UV radiation.

Question 60

Bioremediation

Answer 60

Use of organisms (bacteria, fungi, plants) to remove or neutralize environmental pollutants.