Cells Most Missed

According to the diagram, which statement best describes the general direction of diffusion across the membrane of this cell? The cell membrane is permeable to all materials.

• Glucose would diffuse into the cell

• Protein would diffuse out of the cell

• Carbon dioxide would diffuse out of the cell

• Oxygen would diffuse into the cell

Answer explanation

Diffusion is the passive movement of particles from a region of high concentration to a region of low concentration. In this case, since the cell membrane is permeable to all materials, carbon dioxide, a byproduct of cellular respiration, will diffuse out of the cell, given its higher concentration inside the cell than outside. This aligns with the principle of diffusion and the concept of homeostasis.

While cleaning a saltwater tank, students placed a fish in a bowl filled with pure water. What effect will this have on the fish?

• The cells of the fish will swell.

• The cells of the fish will disintegrate.

• The cells of the fish will shrink and shrivel.

• The cells of the fish will be in balance.

Answer explanation

Placing a saltwater fish into a bowl of pure water will cause the cells of the fish to swell. This is due to osmosis, where water will move from an area of lower salt concentration (the pure water) to an area of higher salt concentration (the fish's cells). This influx of water causes the cells to swell.

Tags

NGSS.MS-LS1-2

Which type of transport moves particles from a higher concentration to a lower concentration without the use of a protein?

• Simple Diffusion

• Osmosis

• Facilitated Diffusion

• Active transport

Answer explanation

Simple diffusion refers to the process where particles move from an area of higher concentration to one of lower concentration, without the use of a transport protein. This process is driven by the concentration gradient, moving substances down their gradient until equilibrium is reached. Thus, it is the correct answer to the question.

The first test tube in the picture contains a sugar solution. The scientist is adding a solution that contains a number of living yeast cells. Later, he notices that the balloon on the test tube is inflated. Based on your knowledge of bioenergetic reactions, which of the following is a valid conclusion that the scientist could draw from his observations?

• The yeast cells are using the sugar provided to produce O₂ through the process of aerobic respiration.

• The yeast cells are using the water in the test tube to produce CO₂ through the process of photosynthesis.

• The yeast cells are using the oxygen provided to produce CO₂ through the process of anaerobic respiration.

• The yeast cells are using the sugar provided to produce CO₂ through the process of anaerobic respiration.

Answer explanation

The correct answer is that yeast cells use the sugar provided to produce CO2 through the process of anaerobic respiration. Yeast, in the absence of oxygen, undergoes anaerobic respiration, or fermentation, which results in the production of CO2. This CO2 is what causes the balloon on the test tube to inflate.

Tags

NGSS.HS-LS1-7

NGSS.HS-LS2-3

Which structure in the leaf controls the opening and closing of the stoma?

• Spongy mesophyll

• Guard cells

• Epidermis

• Cuticle

Answer explanation

The structure in the leaf that controls the opening and closing of the stoma, as mentioned in the given question, is the Guard cells. These cells help regulate the rate of transpiration by opening and closing the stomata, thereby controlling the gas exchange and water vapor loss from the plant's leaves.

Which best explains why muscle cells are different from blood cells?

• A mutation occurs during the development of muscle cells but not in blood cells

• Different genes are activated in muscle cells than in blood cells

• Muscle cells experience different environmental influences than blood cells

• Muscle cells are produced by the brain, but blood cells are produced by the heart

Answer explanation

The reason why muscle cells are different from blood cells is because different genes are activated in both. During cell differentiation, certain genes become active in muscle cells to provide characteristics necessary for muscle function while different genes become active in blood cells for their specific functions. Hence, the characteristics of muscle cells are different from those of blood cells.

Tags

NGSS.HS-LS1-4

The respiratory system includes a layer of cells in the air passages that clean the air before it gets to the lungs. This layer of cells is best classified as:

• An organ

• An organelle

• A tissue

• An organ system

Answer explanation

The layer of cells in the respiratory system that clean the air before it reaches the lungs is best classified as a tissue. A tissue is a group of similar cells that work together to carry out a specific function. In this case, the function is filtering air. Therefore, the correct answer is 'a tissue'.

What is the lowest possible total magnification of the specimen under this microscope?

• 10x

• 200x

• 20x

• 400x

Answer explanation

The total magnification of a microscope is calculated by multiplying the power of the ocular lens (usually 10x) by the power of the objective lens. The question asks for the lowest possible total magnification. Given the options, the correct answer is 200x, which suggests the microscope in question has an objective lens with 20x magnification along with a 10x ocular lens.

This diagram shows a plant cell. Which structure is found in a plant cell but is absent in an animal cell?

• 1

• 2

• 3

• 4

Answer explanation

The question asks about a structure that is found in a plant cell but is absent in an animal cell. Based on the given options, the correct choice corresponds to option 1. This is likely referring to a structure such as a cell wall or chloroplasts, which are present in plant cells but not in animal cells.

Tags

NGSS.MS-LS1-2

A diagram of a cell is shown below. In which structure is protein synthesized?

• 1

• 2

• 3

• 4

Answer explanation

The question asks about the cell structure where protein synthesis occurs. The correct choice suggests protein synthesis occurs in the structure labeled as 2. This pertains to the ribosome, the cellular component that synthesizes proteins.

Tags

NGSS.MS-LS1-2