TRU Biol 2131 Questions and Correct
Answers
What are the 3 tenets of the cell theory? Ans: 1) All organisms are
composed of one or more cells
2) The cell is the structural unit of life
3) Cells can arise only by division from a pre-existing cell
Fundamental properties that are shared by all cells (9)? Ans: -
Cells are highly complex and organized
- Possess a genetic program
- Can reproduce
- Acquire and use energy
- Carry out chemical reactions
- Engage in mechanical activities
- Respond to stimuli
- Capable of self-regulation
How is energy passed from one organism to the next? Ans: Light
energy is converted by photosynthesis into chemical energy that is
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stored in energy-rich carbohydrates. These carbs are source of
energy for animal cells.
Common features between PROK and EUK (9) Ans: PM, genetic
info (DNA), similar mechanisms for transcription/translation,
shared metabolic pathways (glycolysis, TCA), ATP, photosynthesis
mechanisms, protein synthesis, proteasomes, cytoskeletal
filaments built of proteins similar to actin and tubulin
EUK only features Ans: nucleus, complex chromosomes (DNA +
histones), cytoplasmic organelles, complex cytoskeletal
system/flagella/cilia, phagocytosis, diploidy, sexual reproduction,
mitotic spindles
two domains of PROK cells Ans: archae and bacteria
(archae are more closely related to EUK)
EUK specialized cells are formed by Ans: differentiation
As cell size increases, surface area/volume ratio ___ Ans:
decreases
Surface area/volume ratio importance in cell size. Ans: Larger the
cell (cytoplasmic volume) = longer it takes to move things in/out,
generate messages required by cell
- Too big = SA not sufficient to support cell activities
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viruses - obligatory intracellular parasites Ans: means they cannot
produce unless present within a host cell
are viruses considered living organisms? Ans: no; inability to
reproduce/metabolize without host cells
Evolutionary importance of common properties between PROK and
EUK? Ans: The similarities reflect the fact that EUK cells have
evolved almost certainly from PROK ancestors. Due to their
common ancestry, the two types of cells share an identical genetic
code that uses DNA and RNA, a common set of metabolic
pathways, and many common structural features.
Lytic infections Ans: - Use host cell machinery to make new
virions
- Will lyse host to release progeny to infect other cells
lysogenic infections Ans: - Virus integrates DNA into host cell
(provirus)
- No lysing of host
- Effects depend on type of virus
viroid Ans: infectious agent consisting of a small circular RNA
molecule that lacks a protein coat. Thought to cause disease by
interfering with the cell's normal path of gene expression
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Can viruses be treated with antibiotics? Ans: No
Most sugars have the general formula Ans: Ch2O
carbs can be joined together by covalent ___bonds Ans: glycosidic
oligosaccharides - role? Ans: small chains often found covalently
attached to lipids and proteins, converting them into glycolipids
and glycoproteins.
- 15 glucose or fewer per chain
- Role in mediating the interactions of a cell with its environment
and sorting of membrane proteins to different cellular
compartments
glycogen Ans: - highly branched, energy storages.
- Glucose polymer
- animal cells
starch Ans: helical arrangement, energy storage.
Glucose polymer
- Amylose (unbranched) vs amylopectin (branched)
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