Cell Biology
Which organelle acts as the skeleton of the cell?
The cytoskeleton
What are the two macromolecules responsible for carrying out transcription and translation?
RNA polymerase (transcription), ribosomes (translation)
What are chromosomes?
Packaging units for organizing genes
What is the field of science that studies our immune system?
Immunology
Name two traits or processes that occur in living organisms.
1) Metabolism; 2) Organization
>> Other possibilities…
Homeostasis, growth/proliferation, adaptation, responsiveness, reproduction
What are the three components of a nucleotide?
Phosphate group, sugar molecule, base (A,T,C or G)
In a pedigree, what does a filled circle mean?
A female who has inherited a disease
What cells does chemotherapy kill?
Rapidly dividing cells
What are the three biomolecules of life?
Carbohydrates, proteins, fatty acids
Name two differences between prokaryotes and eukaryotes?
1) Prokaryotes have no nucleus, transcription & translation are coupled (happen simultaneously); 2) Eukaryotes have a nucleus, transcription & translation occurs in two steps, spatially divided (transcription – nucleus; translation – cytoplasm)
>> Other possibilities…
Prokaryotes: generally, are very small, do not have membrane-bound compartments, grow at fast rate
Eukaryotes: tend to be pretty large, have several membrane bound organelles
What is the Law of Dominance?
An organism with alternate forms of a gene will express the form that is dominant
What does hemotoxin stain?
The cell nucleus, DNA/RNA, acidic structures
Where are large biomolecules broken down into components to be recycled and reused?
Lysosomes, peroxisomes
What is the bond that links polypeptide monomers (amino acids) together?
Peptide bond
Name a type of mutation – define it and provide an example.
Insertion – type of mutation in which one or more nucleotide base pairs are added into a DNA sequence. For example, our normal DNA sequence is ‘CTGG’; following an insertion mutation (2 base pair addition), the mutated DNA sequence becomes ‘CTACGG’.
>> Other possibilities…
Deletion – involves the loss of one or more nucleotides from a segment of DNA. For example, normal DNA sequence: CTGGA >> mutated: CGA;
Substitution – when a single nucleotide is substituted with another. For example, normal DNA sequence: CTGG >> mutated: CAGG;
> Frameshift – an insertion or deletion of nucleotide bases has occurred that are not in multiples of three *Recall the triplet nature of gene expression by codons*. For example, normal DNA sequence: ACG AGG > results in the production of Thr, Arg during translation; +1 frameshift mutation: A CGA > only Arg is produced (‘AGG’, ‘CGA’ yield the same amino acid in this case)
How does someone get cancer? Give three sources.
Old age, occupational factors (exposure to harmful chemicals), genetics
>> Other possibilities…
Lifestyle – smoking, diet (high consumption of processed foods, low intake of plant-based ingredients), substance abuse (high consumption of drugs, alcohol), low activity level (high body fat, obesity); environment – sunlight, contaminated water/food sources; infection – viruses
Name a mammalian cell that has no nucleus and one that contains many.
1) Red blood cell; 2) Megakaryocyte
*(1) Red blood cells have a process of maturation, during which they eliminate their nucleus, many organelles (mitochondria, Golgi, ER) to accommodate maximum space for hemoglobin – early stages (precursors/high abundance in neonates) or in the case of certain diseases (megaloblastic anemia), nucleated cells can be present
*(2) These are hematopoietic cells responsible for the production of blood platelets
After translation of an mRNA sequence into an amino acid sequence on the ribosome, the process for forming a protein has been completed. Is this a true or false statement? Justify answer.
False – the polypeptide needs to undergo additional folding into its proper 3D confirmation to become functional
What is a genetic model? Provide an example and what it is used for.
Genetic models are biological systems which allow the study of genetic phenomena. For example, certain pure-bred dog varieties may serve as a model for investigating genetic bottlenecks.
>> Other models…
Mice – used to study disease and biological processes in humans; Water flea – used to study epigenetics; Nematode – used to study human disease (e.g., metabolic disorders, obesity, diabetes) *Recall Dr Pamela Padilla’s research
Why is cancer referred to as a ‘disease of age’?
The percentage of incidence is much higher after 60 years of age – simply put, mutations accumulate in our tissues throughout life and overall damage to cell populations also increases over time. The longer we live, the more common it is for certain types of cancer to develop.