Question

Which of the following conditions is required for diffusion to occur?

Group of answer choices

available energy in the form of ATP

a concentration difference

a selectively permeable membrane

a living cell

Materials can be limited from entering the cell by

Group of answer choices

limiting the amount of energy available to the cell

controlling which transporter proteins are available on the cell surface

controlling the movement of water across the cell surface

controlling access to the Golgi apparatus

For cells in which oxygen gas (O₂) crosses the membrane by simple diffusion, what determines the rate at which oxygen enters the cell?

Group of answer choices

the amount of ATP produced by the cell

the concentration of carbon dioxide molecules on either side of the membrane

the number of carrier proteins in the membrane

the concentration of O₂ on either side of the membrane

The following statement is TRUE: when a cell is deprived of oxygen its lysosomes tend to burst and release their contents into the cell. Predict which of the following events would be the most likely END RESULT in a cell deprived of oxygen.

Group of answer choices

undergo cell division

undergo self digestion and die

recycle damaged organelles

produce additional endoplasmic reticulum

produce replacement lysosome

Exercise capacity depends on various factors. It is well known that trainability and exercise capacity differs from one person to another, and this individual difference can be determined by both life-style and genetic factors. What organelle in the muscle cells is most likely to be responsible for very high or very low exercise capacity?

Group of answer choices

plasma membrane

chloroplast

rough endoplasmic reticulum

lysosome

mitochondria

A young toddler is taken to the doctor because he has abnormally greasy bowel movements. The doctor determines that fats are not being digested in the diet due to a deficiency of an enzyme called pancreatic lipase, which is necessary to break down dietary fats in the small intestine. Which organelle in the pancreas cell could be responsible for this disorder?

Group of answer choices

free ribosomes

flagella

mitochondria

Golgi apparatus

Chloroplast

If one strand of a DNA molecule has the sequence 5' ACGTTA 3' the other strand will have the sequence:

Group of answer choices

3'ATTGCA5'

3' TAACGT 5'

3'TGCAAT 5'

3'UAACGU5'

Even though sickle cell anemia is usually fatal to individuals who have 2 copies of the sickle cell gene, the disease persists because:

Group of answer choices

there is no way of knowing which individuals carry the sickle cell gene

individuals with sickle cell anemia don't get adequate health care

none of the answers are correct

gene therapy has alleviated the condition

individuals with one copy of the sickle cell gene are resistant to malaria

The principal defect that leads to the development of sickle hemoglobin involves the substitution of the correct amino acid _______ for_________, an incorrect amino acid in the polypeptide chain.

Group of answer choices

glutamic acid....valine

valine....glycine

phenylalanine....lysine

glutamine....lysine

glutamic acid....phenylalanine

Answer 1

Which of the following condition is required for diffusion to occur?

Diffusion is a process through which molecules move from higher concentration to lower concentration. The difference in concentration is known as the concentration gradient. It involves gases as well as liquids. It only requires a concentration difference for diffusion to occur is the right answer. Diffusion is a passive process it does not require energy in the form of ATP. The transport of molecules that require selectively permeable membrane is called osmosis. Diffusion does not require membrane to occur. It’s not necessary for diffusion to occur in a living cell. It can occur in glass eg sugar cube in a glass of water dissolve and sweeten the whole water as a result of diffusion. Scented stick fragrance disperse in the whole room as a result of diffusion.

Materials can be limited from entering the cell by:

Limiting the amount of energy available to cells is not right because energy is required to perform the different metabolic activities of cell which is required for proper cell function. Limiting available energy will affect cell function. Transporter proteins which are present on the cell surface are involved in the transport of molecule across the cell. These transporter proteins are highly specific for the molecules they transport. By limiting their availability (control at gene expression) on the cell surface entry of materials can be limited. So, controlling which transporter proteins are available on the cell surface is the right answer. Water transport across the membrane occurs either through diffusion or osmosis. There are water selective pores (aquaporins) which are specific for water molecule ana some times small solutes. So, controlling the movement of water across the cell surface is no right answer. Golgi apparatus is a cell organelle that is involved in modification, packaging, and secretion of proteins. Controlling access to the Golgi apparatus is no right answer because it is not involved in the transport of materials in the cell.

For cells in which oxygen gas (O2) crosses the membrane by simple diffusion, what determines the rate at which oxygen enters the cell?

The amount of ATP produced by the cells shows the energy status of a cell. It is not the right answer because oxygen crosses the membrane by simple diffusion which does not require energy. The CO2 also crosses the membrane by simple diffusion process (means from higher to lower concentration). Cells generate CO2 by oxidation of metabolite, therefore, have higher concentration inside the cell that results in outside movement of CO2 across the cell. Therefore, the concentration of carbon dioxide molecules on either side of the membrane is not the right answer. The number of carrier proteins in the membrane is not the right answer because oxygen transport across the cell membrane occurs via a simple diffusion process which does not require any proteins. The concentration of oxygen on either side of the membrane is the right answer because oxygen diffuses across the membrane by diffusion process means from the area of higher concentration ( which is in the blood) to the lower concentration ( inside the cell).

The following statement is True: when a cell is deprived of oxygen its lysosome tend to burst and release their contents into the cell. Predict which of the following events would be most likely end in a cell deprived of oxygen:

Cell division occurs under favorable conditions when cells tend to grow their number or cell repair or gametes formation. So, undergo cell division is not the right answer under the mentioned conditions. Cells will undergo self-digestion and die is the right answer because lysosome contains digestive enzymes and bursting of lysosome results in the release of these enzymes in the cell which starts degradation and kills the cell organelles and cell will eventually die. Recycle damaged organelles are not the right answer because digestive enzymes of lysosomes will eat all organelle so there will be no recycle. Endoplasmic reticulum (ER) and lysosome is also a cell organelle it also can not produce so the production of ER and replacement of lysosome is not the right answer because once cells committed to cell death it will go only for that process.

Exercise capacity depends on various factors. It is well known that trainability and exercise capacity differs from person to another and this individual difference can be determined by both lifestyle and genetic factors. What organelle in the muscle cell is most likely to be responsible for high or low exercise capacity?

Plasma membrane primary functions are: it provides a barrier between the intracellular and extracellular environment and control the transports of different molecules across the membrane. So, the plasma membrane is not the right answer. The chloroplast is a cell organelle which is the site of photosynthesis in plants therefore it is also not the right answer. The rough endoplasmic reticulum is involved in protein trafficking and modification so this is also not the right answer. The lysosome is membrane-bound cell organelle which contain digestive enzymes and are involve in the removal of waste products therefore lysosomes are not the right answer. Mitochondria also are known as a powerhouse of the cell is the right answer because it is the mitochondria that produce energy in the form of ATP which is used by the cell to perform its function. Mitochondria generate this energy by complete oxidation of glucose ( cellular respiration) through a series of enzyme-catalyzed reactions (Kreb’s cycle, electron transport chain and oxidative phosphorylation).