Introduction to cell biology

Drosophila melanogaster is a/an __________. This type of animal is the most abundant of all animal species, making it an appropriate choice as an experimental model. - insect - bird - amphibian - mammal

insect

Cells that are specialized for the secretion of proteins are likely to have which of the following features? - long bundles of actin/myosin proteins - small volume of cytoplasm - large population of mitochondria - enlarged endoplasmic reticulum

enlarged endoplasmic reticulum

Which three characteristics best support the rapid evolution of prokaryotic populations? - microscopic, motile, anaerobic - aerobic, motile, rapid growth - no organelles, cell wall, can exchange DNA - large population, rapid growth, can exchange DNA

large population, rapid growth, can exchange DNA

Prokaryotic cells do not possess - a nucleus - replication machinery - ribosomes - membrane bilayers

a nucleus

Proteins are important architectural and catalytic components within the cell, helping to determine its chemistry, its shape, and its ability to respond to changes in the environment. Remarkably, all of the different proteins in a cell are made from the same 20 __________. By linking them in different sequences, the cell can make protein molecules with different conformations and surface chemistries, and therefore different functions. - nucleotides -sugars -amino acids -fatty acids

amino acids

The world of prokaryotes is divided into two domains (bacteria and archaea), each as different from each other as from eukaryotes. Select the observable characteristic that BEST separates archaea from bacteria. - can metabolize inorganic substances - are found in extremely harsh environments - thrive in anaerobic conditions - are photosynthetic organisms

are found in extremely harsh environments

Zebrafish (Danio rerio) are especially useful in the study of early development because their embryos - are exceptionally large. - develop slowly - are transparent - are pigmented

are transparent

Choose the phrase that best completes this sentence: Microtubules __________ and are required to pull duplicated chromosomes to opposite poles of dividing cells. -generate contractile forces -are intermediate in thickness -can rapidly reorganize -are found in especially large numbers in muscle cells

can rapidly reorganize

Living systems are incredibly diverse in size, shape, environment, and behavior. It is estimated that there are between 10 million and 100 million different species. Despite this wide variety of organisms, it remains difficult to define what it means to say something is alive. Which of the following can be described as the smallest living unit? - DNA - cell - organelle -protein

cell

Despite the differences between eukaryotic and prokaryotic cells, prokaryotes have proteins that are distantly related to eukaryotic actin filaments and microtubules. What is likely to be the most ancient function of the cytoskeleton? - cell motility - vesicle transport - membrane support - cell division

cell division

The nucleus, an organelle found in eukaryotic cells, confines the __________, keeping them separated from other components of the cell. - lysosomes - chromosomes - peroxisomes - ribosomes

chromosomes

Which of the following choices BEST describes the role of the lysosome? - transport of material to the golgi apparatus - clean-up, recycling and disposal of macromolecules - sorting of transport vesicles - the storage of excess macromolecules

clean-up, recycling and disposal of macromolecules

Select the option that correctly finishes the following statement: A cell's genome - is defined as all the genes being used to make protein - contains all of a cell's DNA - constantly changes depending upon the cell's environment - is altered during embryonic development

contains all of a cell's DNA

Brewer's yeast, apart from being an irreplaceable asset in the brewery and in the bakery, is an experimental organism used to study eukaryotic cells. However, it does have some limitations. Select all the processes below that CANNOT be studied in yeast. - differentiation - motility -exocytosis -cell division

differentiation

The cell constantly exchanges materials by bringing nutrients in from the external environment and shuttling unwanted by-products back out. Which term describes the process by which external materials are captured inside transport vesicles and brought into the cell? - degradation - exocytosis - phagocytosis - endocytosis

endocytosis

Mitochondria contain their own genome, are able to duplicate, and actually divide on a different time line from the rest of the cell. Nevertheless, mitochondria cannot function for long when isolated from the cell because they are - viruses - parasites - endosymbionts - anaerobes

endosymbionts

Changes in DNA sequence from one generation to the next may result in offspring that are altered in fitness compared with their parents. The process of change and selection over the course of many generations is the basis of - mutation - evolution - heredity - reproduction

evolution

Eukaryotic cells are able to trigger the release of material from secretory vesicles to the extracellular space using a process called exocytosis. An example of materials commonly released this way is - hormones - nucleic acids - sugars - cytosolic proteins

hormones

What unit of length would you generally use to measure a typical plant or animal cell?

micrometers

The mitochondrial proteins found in the inner membrane are involved in the conversion of ADP to ATP, a source of energy for the cell. This process consumes which of the following substances? - oxygen - nitrogen - sulfur -carbon dioxide

oxygen

__________ are fairly small organelles that provide a safe place within the cell to carry out certain biochemical reactions that generate harmful, highly reactive oxygen species. These chemicals are both generated and broken down in the same location. - nucleosomes - lysosomes - peroxisomes - endosomes

peroxisomes

Caenorhabditis elegans is a nematode. During its development, it produces more than 1000 cells. However, the adult worm has only 959 somatic cells. The process by which 131 cells are specifically targeted for destruction is called - directed cell pruning - programmed cell death - autophagy - necrosis

programmed cell death

The central dogma provides a framework for thinking about how genetic information is copied and used to produce structural and catalytic components of the cell. From the choices below, select the order of biochemical processes that best correlates with the tenets of the central dogma. -replication, transcription, translation -replication, translation, transcription -translation, transcription, replication -translation, replication, transcription

replication, transcription, translation

Select the option that BEST finishes the following statement: Evolution is a process - that can be understood based on the principles of mutation and selection - that results from repeated cycles of adaption over billions of years - by which all present-day cells arose from 4-5 different ancestral cells - that requires hundreds of thousands of years

that can be understood based on the principles of mutation and selection.

Scientists learned that cell death is a normal and even important part of life by studying the development of the nematode worm C. elegans. What was the most important feature of C. elegans for the study of programmed cell death? - The nematode is smaller and simpler than the fruit fly - Seventy percent of C.elegans genes have homologs in humans - The developmental pathway of each cell in the adult worm was known - Its genome was partially sequenced

the developmental pathway of each cell in the adult worm was known

Cell biologists employ targeted fluorescent dyes or modified fluorescent proteins in both standard fluorescence microscopy and confocal microscopy to observe specific details in the cell. Even though fluorescence permits better visualization, the resolving power is essentially the same as that of a standard light microscope because the resolving power of a fluorescent microscope is still limited by the __________ of visible light. - adsorption - intensity - filtering - wavelength

wavelenght

What is the smallest distance two points can be separated and still resolved using light microscopy? - 20nm - 0,2 μm - 2 μm - 200 μm

0,2 μm

Which pair of values best fills in the blanks in this statement: On average, eukaryotic cells are __________ times longer and have __________ times more volume than prokaryotic cells. - 5; 100 - 10; 200 - 10; 100 - 10; 1000

10; 1000

Which statement is NOT true about mutations? - A mutation is a change in the DNA that can generate offspring less fit for survival than their parents. - A mutation can be a result of imperfect DNA duplication. - A mutation is a result of sexual reproduction. - A mutation is a change in the DNA that can generate offspring that are as fit for survival as their parents are.

A mutation is a result of sexual reproduction.

Biologists cannot possibly study all living species. Instead, they try to understand cell behavior by studying a select subset of species. Which of the following characteristics are useful in an organism chosen for use as a model in laboratory studies? - Amenability to genetic manipulation - Ability to grow under controlled conditions - Rapid rate of reproduction - All of these

All of these

Which species was the key model organism for the advancement of molecular biology (understanding DNA replication, decoding the DNA to make proteins, etc.)? - E.coli - D. melanogaster - S. pombe - C.elegans

E. coli

Which statement is NOT true about the events/conclusions from studies during the mid-1800s surrounding the discovery of cells? - Cells came to be known as the smallest universal building block of living organisms. - Scientists came to the conclusion that new cells can form spontaneously from the remnants of ruptured cells. - Light microscopy was essential in demonstrating the commonalities between plant and animal tissues. - New cells arise from the growth and division of previously existing cells.

Scientists came to the conclusion that new cells can form spontaneously from the remnants of ruptured cells.

Mitochondria perform cellular respiration, a process that uses oxygen, generates carbon dioxide, and produces chemical energy for the cell. Which answer below indicates a correct pairing of the material "burned" and the form of energy produced during cellular respiration? - fat, ADP - sugar, fat - sugar, ATP - fat, protein

Sugar, ATP

The cytoskeleton provides support, structure, motility, and organization, and it forms tracks to direct organelle and vesicle transport. Which of the cytoskeletal elements listed below is the thickest? -actin filaments -microtubules -intermediate filaments -none of these (all have the same thickness)

microtubules

Which of the following organelles has both an outer and an inner membrane? - endoplasmic reticulum - mitochondrion -lysosome - peroxisome

mitokondrien

The __________ __________ is made up of two concentric membranes and is continuous with the membrane of the endoplasmic reticulum. - plasma membrane - golgi network - mitochondrial membrane - nuclear envelope

nuclear envelope