1. Adipose tissue is a form of _______ tissue. A. epithelial B. muscle C. nerve D. connective

(a) Identify the most likely mode of transport across the membrane for substance L. Explain how information provided helps deter

Viefleur [7K]

Active transport occurs against the electrochemical gradient. It needs energy to move molecules from the lower concentration side to the higher concentration side. The mode of transport is active transport. 

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There are three main different types of transport across the membrane

Simple diffusion ⇒ Does not need energy to occur
Facilitated transport ⇒ Does not need energy to occur
Active transport ⇒ Needs energy to occur

Active transport is the transport of molecules that move against the electrochemical gradient, so it does need energy to happen.

Molecules move from the lower concentration side to the higher concentration side of the membrane.

Carrier proteins are in charge of active transport. The needed energy might proceed from the ATP molecules or the membrane's electric potential.

In the exposed example, a scientist wants to determine how substance L enters a cells in a culture.

The cells maintain a 120 mM intracellular concentration of substance L.

Varying external concentrations of substance L (10 to 100 mM) in culture medium (Table 1).

Table 1. Rate of entry of substance L into mammalian cells in culture

External concentration of substance(mM) Rate of entry of substance L

10 5%

20 25%

30 45%

40 65%

50 80%

60 90%

70 95%

80 100%

90 100%

100 100%

Now, we need to identify the most likely mode of transport across the membrane for substance L, and explain how information provided helps determine the most likely mode of transport.

We know that the intracellular concentration is 120mM.

As we can see, this concentration exceeds all of the culture media concentrations. Yet, the substance keep moving into the cell.

As the concentration inside the cell is always higher than the concentration outside, we can assume that this is not passive transport because the molecule transport is going against its concentration gradient.

Hence, the remaining option is active transport. And as said before, we can see it because the substance keeps crossing the membrane toward the cell interior despite its concentration being higher in the interior of the cell than in the exterior.

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6 0

3 years ago

Molecular phylogenies show all land plants are a monophyletic group. This suggests ________.

guapka [62]

Answer:

D. There was a single transition from aquatic to terrestrial habitats

Explanation:

Based on the molecular differences at the level of DNA sequence and inheritance, the molecular phylogenies show that all land plants are a monophyletic group. This is why it suggests a single transition from aquatic to terrestrial habitats occur.

5 0

4 years ago

A white-flowered rhododendron is crossed with a red-flowered rhododendron. The alleles are codominant. What color flowers will t

slega [8]

White and red spotted

3 0

3 years ago

Thermococcus and thermoplasma what do they have in common?

pickupchik [31]

Explanation:

Both Thermococcus and Thermoplasma are unicellular organisms that can live in extreme environments. Based on the concept of domains, what do they have in common? They both belong to domain Archaea. ... They both belong to domain Eukarya.

3 0

3 years ago

Determine whether each of the following is a characteristic of the life cycle of a seed plant, a seedless plant, or both. Sporop

kumpel [21]

Sporophyte generation - It is found in both seed and seedless plant. Dominant phase of the life cycle of the seedless plants is diploid sporophyte while in seed plant male and female gametes fuses to produces a diploid zygote which develops into a sporophyte.

Pollination - It occurs in seed plants only

Sporophyte contains male and female reproductive structures - It is found in both seed and seedless plant.

Single fertilization - It occurs in both seed and seedless plant

Sperm cells transported by water to egg cells - seedless plant only

8 0

3 years ago

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