Exam Multiple Questions Flashcards
What did Pasteur prove the theory of spontaneous generation wrong ?
That living organisms can form without an ancestor /ancestors
Which of the following statements about endomembrane system are true ?
Lysosomes degrade membrane proteins
Endosomes form after membrane budding from the plasma membrane
Vesicle traffic occurs between the endoplasmuc reticulum and the Golgi apparatus
Coast proteins, rab proteins and SNARE proteins participate in vesicle trafficking
Regarding ion gradient across membrane , which statement is true ?
Create billion fold concentration difference between compartments
Are maintained by the triggered opening of passive transmembrane channels
May store electrochemical potential energy, some of which may be used drive other processes
Are used to make ATP in mitochondria
Which of the below is a type of stress that cells are facing /can face?
All false
- Starvation ]
- High frequency radiation
Oxidative stress
Hypoxia
High /Low temp
Cell may face nay of above
The genetic code ?
Shows how nucleotide sequence of messenger RNA (mRNA) specifies the amino acid sequence of proteins
Lipid can form structures like micelles and bilayer because ?
Their structure , as the lipid molecules contains parts that interact strongly with water and other parts that do not .
What is defined by generally the first AUG to be found on a mRNA ?
A methionine , which also acts as the start signal for polypeptide synthesis
Which of the following statements is true about a human energy metabolism ?
Electron transport during oxidative phosphorylation generates a proton gradient at the inner mitochondrial membrane that is used for ATP generation .
Which of the following statements apply to the process of meiosis (reduction division to form gametes )?
There are two rounds of cell division , which accomplish different tasks
Which of the following species are suitable used as a Model organism for studying animal development , for the reason given ?
The worn Caenorhabditis elegans , because it has a short life cycle and its limited size allows a detailed understanding of developmental pathways .
What do epithelial cells do ?
They share their plasma membrane with firbolasts
They are embedded in an extracellaur matrix and rarely touch each other
They use haemoglobin to absorb and release oxyegb
They form adherens junctions with other epithelial cells forms sheets
Which of the Following features distinguish neurotransmission from endocrine (hormonal) signalling ?
Hormones signal to any cell they encounter that has a receptor for that hormone whereas neurones only signal to cells with what they have established close synaptic connections .
How can the same messenger molecule have different effects of different cell types ?
Different cells may use the same receptor but differ in the way the signal is processed , and in the receptors of responses that may be provoked by the signal
Which of the following statements best describe an aspect of neuronal signalling ?
The action potential travels on time scales of milliseconds.
How is the cell regulated in normal animal cells ?
DNA damage leads to cell cycle arrest and if the damage is too extensive to be repairs to cell death
