Genetics and Model Organisms Quiz

Cells, a fundamental unit of life, are the building blocks of all living organisms.

Developed by Schleiden and Schwann, cell theory states that all living organisms are composed of one or more cells, cells are the basic unit of structure and organization in organisms, and cells arise from pre-existing cells.

These cells lack a nucleus, have a simple structure, and are found in bacteria and archaebacteria.

These cells have a true nucleus, a complex structure, and are found in all other organisms, including plants, animals, fungi, and protozoa.

A simple but precise microscope used by Antoni van Leeuwenhoek, enabling him to observe microscopic organisms like bacteria and protozoa.

Small, single-celled organisms that are visible under a microscope and can be either plant- or animal-like.

The process where cells multiply by dividing into two identical daughter cells.

The theory that life can arise spontaneously from non-living matter, which has been disproven by cell theory.

A transparent, nematode worm with a simple body plan, consisting of about 959 somatic cells and 1000 to 2000 germ cells.

C. elegans is used to study animal development, cell differentiation, the nervous system, aging, cell death, and the structure of the genome.

C. elegans can reproduce both sexually and asexually. Hermaphrodites, the most common form, possess both male and female reproductive organs and can self-fertilize. Males with a copulatory tail can mate with hermaphrodites, increasing genetic diversity.

From egg to adult, C. elegans takes about 3-5 days to mature. Adults live for 2-3 weeks and can lay hundreds of eggs.

C. elegans was the first multicellular organism to have its genome sequenced, containing about 19,000 protein-coding genes.

Its transparency enables researchers to study cell differentiation and other developmental processes in a living organism.

Approximately 36% of C. elegans genes have human homologues, making it crucial for studying human biology.

Sydney Brenner spearheaded the use of C. elegans as a model organism for research, particularly in neural development.

The ability of an objective lens to distinguish two closely spaced points as separate and distinct.

The factor by which an image appears to be enlarged.

A type of microscope that uses a beam of electrons to illuminate the sample, providing high magnification and resolution.

A type of microscope that uses visible light to illuminate the sample, providing lower magnification and resolution compared to electron microscopy.

A technique that allows visualization of cellular structures in a living organism, often using fluorescent dyes.

A type of microscopy that uses a combination of lenses and a light source to magnify and illuminate the sample.

A type of optical microscopy technique that enhances resolution beyond the diffraction limit of light, allowing for visualization of smaller details.

The study of the nervous system and its functions.

The fruit fly, Drosophila melanogaster, became a model organism for genetic research due to its short life cycle, numerous offspring, and easily identifiable mutations, like the famous white-eyed fly.

Thomas Hunt Morgan's team discovered that genetic traits are located on chromosomes and inherited across generations. They mapped the location of genes on chromosomes by observing how traits were passed on in controlled crosses.

The phenomenon where parts of different chromosomes can exchange genetic material during cell division.

The complete sequence of a fruit fly's genome contains around 14,000 genes and 180 million base pairs.

The fruit fly's complete genome sequence is freely available for scientists to research. This allows researchers to compare fly genes to human genes, potentially identifying links to human diseases.

Research on the fruit fly has led to the discovery of genes that control development and differentiation in animals. This knowledge has been crucial for understanding how organisms develop.

Arabidopsis thaliana, commonly known as thale cress, is a small flowering plant that is widely used as a model organism in plant biology. Its small size, fast life cycle, and ease of manipulation makes it ideal for studying various plant processes.

Arabidopsis thaliana is chosen for its rapid growth rate and large number of offspring, allowing researchers to study multiple generations within a short period.

Visualizing proteins inside living cells without fixing or staining, a key technique that revolutionized biology.

A method to track the movement of GFP-labeled proteins in living cells, where a bleached region recovers fluorescence as unbleached molecules move in. This measures protein movement.

Using fluorescent markers that interact, like two GFP variants, to detect protein interactions based on energy transfer. If they are close, the energy is transferred, resulting in a different color.

This microscopy technique provides detailed images of a single plane of the sample, focusing a laser onto a specific depth and eliminating out-of-focus light to create clearer views.

It was the beginning of using GFP in research, showing the potential of illuminating living cells with a glowing marker.

C. elegans is a transparent nematode worm with a simple body plan, making it an ideal model organism for studying various biological processes.

Researchers can study how genes are expressed in living cells, providing valuable insights into the function of genes and the regulation of gene expression.

A process that involves using increasing concentrations of ethanol to remove water from the sample, preparing it for embedding.

The process of infiltrating the sample with a solid medium, like paraffin or resin, to provide structural support and allow for sectioning.

Thin slices of tissue prepared for microscopic examination, typically obtained using a microtome or ultramicrotome.

A type of embedding medium used for optical microscopy, made of a mixture of waxes, allowing thin sections for light to pass through.

A harder embedding medium used for electron microscopy, allowing finer cuts and better resolution.

The process of applying dyes to stained histological sections to reveal different cell structures and components.

Basic dyes, like methylene blue, have an affinity for acidic substances, such as DNA, highlighting the cell nucleus.

Acid dyes, like eosin, have an affinity for basic substances, like proteins, revealing the cell cytoplasm and extracellular matrix.