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Dat Biology Questions and Answers 2024/2025( A+ GRADED 100% VERIFIED).
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Dat Biology QuestionsWhat are the seven components of modern day cell theory? - ANS 1. All known living things
are made up of one or more cells
2. All living cells arise from pre-existing cells by division.
3. The cell is the fundamental unit of structure and function in all living organisms.
4. The activity of an organism depends on the total activity of independent cells.
5. Energy flow (metabolism and biochemistry) occurs within cells.
6. Cells contain DNA which is found specifically in the chromosome and RNA found in the cell
nucleus and cytoplasm.
7. All cells are basically the same in chemical composition in organisms of similar species
A scientist wants to detach a peripheral membrane protein from the exterior of a cell membrane.
Which is the best method to do so?
A. change salt concentrations
B. Perform a light centrifuge
C. Add a detergent
D. Change the temperature of a solution
E. Run a small current through the solution - ANS A. change salt concentrations
Peripheral membrane proteins are held in place by electrostatic interactions and hydrogen
bonding. They are generally hydrophilic. Changing the salt concentration (a "salt wash") or the
pH would disrupt both of these types of bonds and release the peripheral membrane protein
from the cell membrane. A light centrifuge will precipitate cells and nuclei at most, only heavy
centrifuges extract small soluble proteins.
All of the following were observed by Miller-Urey in their classic experiment to check the
hypothesis of the "chemical origins of life" EXCEPT for one. Which one is the EXCEPTION?
A. Methane
B. Amino acids
C. Ammonia
D. Organic compounds
, E. Nucleic acids - ANS Nucleic acids
What was the Miller-Urey experiment - ANS The Miller-Urey experiment used ammonia,
methane, water and hydrogen sealed in a sterile arrangement of tubes and flasks with
connecting loops. One flask was half-filled with liquid water and the other with 2 electrodes (to
simulate lighting in early earth). The flask with water was heated to simulate the temperature of
early Earth, and sparks were fired from the electrodes to simulate lightning. After 2 weeks, they
observed several organic compounds, amino acids (11 out of 20) and their base starting
materials. However, no complete nucleic acids were observed.
A toxin is released into the body that promotes the degeneration of microfilaments. Which of
these structures is most likely to be directly affected?
A. spindle fibers radiate from centrioles
B. Lysosomes
C. The extracellular matrix
D. Chromosomes
E. Muscles cells - ANS E. muscle cells
Our muscles are made of long chains of cytoskeleton composed of two filaments - actin and
myosin. Of these, actin is a microfilament, while myosin is a motor protein. If actin degenerates,
then our muscles would not contract, thus, our answer is E. The spindle fibers radiating from the
centrioles are microtubules. A lysosome is an organelle that is involved in phagocytosis. The
extracellular matrix consists of protein fibers and glycosaminoglycans. Chromosomes are made
of nucleic acids
What are Pili - ANS Pili are small short "hairs" called fimbriae on the surface of bacteria that
can be used in the exchange of genetic material between bacteria and in cell adhesion.
Glycolysis is best described as what type of process?
A. Exergonic
B. Endergonic
C. Isotonic
D. Hypertonic
E. Hypotonic - ANS A. Exergonic
Glycolysis requires the use of energy when the glucose molecule is broken into two pyruvates.
The two steps in which ATP is used can be considered endergonic, however, overall glycolysis
produces energy to be consumed by the cells. If energy is released, then the reaction is
exergonic. The concentration terms, isotonic, hypertonic, and hypotonic refer to the relative
concentrations of different environments and this is not related to cell thermodynamics or a cell's
use or production of energy.
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