Which of the following structures in the ileum transports fatty acid and glycerol?

Here are the solutions for the questions from the image:

18. Which of the following structures in the ileum transports fatty acid and glycerol?
In the ileum (part of the small intestine), digested fats (fatty acids and glycerol) are absorbed into the lacteals. Lacteals are lymphatic capillaries located in the villi of the small intestine.

The correct option is B. Lacteal.

19. Where in the mammalian skin is sebum produced?
Sebum is an oily substance that lubricates the skin and hair. It is produced by the sebaceous glands, which are exocrine glands found in the dermis of the skin, usually associated with hair follicles.

The correct option is B. Sebaceous gland.

20. Carbon dioxide concentration in an industrial zone can be kept constant by:
Afforestation refers to the planting of trees in areas where there were no trees previously. Trees absorb carbon dioxide during photosynthesis, thus helping to reduce its concentration in the atmosphere. Combustion of fuel and deforestation increase CO2, while grazing has a less direct impact on atmospheric CO2 levels.

The correct option is C. Afforestation.

SECTION III (QUESTIONS 21-25)
Directions: For each of the questions below, ONE or MORE of the responses is (are) correct. Decide which of the responses is (are) correct. Then choose:
A. If 1, 2 and 3 are all correct
B. If 1 and 2 only are correct
C. If 2 and 3 only are correct
D. If 1 only is correct

21. A food chain:

1. Is a complex network of feeding relationships. (Incorrect, this describes a food web)
2. Has a producer at the base. (Correct, food chains start with producers)
3. Is a linear sequence of feeding. (Correct, food chains show a single pathway of energy flow)

Therefore, statements 2 and 3 are correct.

The correct option is C. 2 and 3 only.

22. The following features maximize absorption of sunlight in leaves:

1. Thin epidermis. (Incorrect, the epidermis is usually transparent to allow light through, but its thickness isn't the primary factor for maximizing absorption; rather, the internal structure like palisade cells are key).
2. Large surface area. (Correct, a large surface area allows the leaf to capture more sunlight).

Therefore, only statement 2 is correct.

The correct option is D. 1 only. (Note: The options provided in the table for D is "1 only", which corresponds to statement 2 being correct in this context, assuming the question meant "2 only" for option D. Given the options, if only 2 is correct, and D is "1 only", there might be a mismatch in the question's options or numbering. However, based on the biological fact, only "Large surface area" is a correct feature for maximizing sunlight absorption among the given choices. If we strictly follow the options, and assuming "1 only" refers to the first correct statement, which is not the case here. Let's re-evaluate the options based on the table: A=1,2,3; B=1,2; C=2,3; D=1. If only statement 2 is correct, none of the options A, B, C, D directly represent "2 only". However, if we assume there's a typo in the options and D should be "2 only", then D would be the answer. If we must choose from the given options, and only 2 is correct, there is an issue. Let's assume the question meant to list "2 only" as an option. If not, the question is flawed in its options for this specific problem. Given the common structure of these questions, it's highly probable that 'D' is intended to represent '2 only' in this context, or there's a mislabeling. For the purpose of providing the best possible answer based on biological accuracy, 'Large surface area' is the correct feature. If we are forced to pick from the given options, and assuming 'D' is meant to represent the single correct statement, then there's an error in the question's options. Let's assume the option D means "only the statement that is correct". In this case, only statement 2 is correct. If the options are strictly 1,2,3 / 1,2 / 2,3 / 1, then there is no correct option for "2 only". I will proceed by stating that only statement 2 is correct, and acknowledge the potential issue with the provided options.)

Let's re-examine the options for Q22.

1. Thin epidermis. (This is generally true for maximizing light penetration, but not absorption itself. The epidermis is transparent.)
2. Large surface area. (This is definitely true for maximizing absorption of sunlight.)

If both 1 and 2 are considered correct, then B would be the answer. However, "thin epidermis" is more about light penetration than absorption. The primary structures for absorption are the chloroplasts in the palisade and spongy mesophyll. A large surface area directly increases the amount of light intercepted.

Let's consider the possibility that "Thin epidermis" is also considered a feature that maximizes the overall process of sunlight absorption by allowing more light to reach the photosynthetic cells. In many contexts, a thin, transparent epidermis is indeed listed as an adaptation for efficient photosynthesis.

If both 1 and 2 are considered correct, then the answer would be B. 1 and 2 only.

23. When a complete ring of bark of a tree is peeled off:

1. Active transport of minerals occur. (Incorrect, mineral transport primarily occurs in the xylem, which is internal to the bark and not removed by ringing.)
2. Phloem is destroyed. (Correct, the phloem is located in the bark, so removing a ring of bark destroys the phloem.)
3. No translocation of food occurs. (Correct, phloem is responsible for translocating food (sugars) from leaves to other parts of the plant. If phloem is destroyed, food translocation stops.)

Therefore, statements 2 and 3 are correct.

The correct option is C. 2 and 3 only.

24. Decomposers in an ecosystem:

1. Feed saprophytically. (Correct, decomposers like fungi and bacteria obtain nutrients by breaking down dead organic matter.)
2. Breakdown dead bodies. (Correct, this is their primary role.)
3. Release nutrients. (Correct, by breaking down dead bodies, they return essential nutrients to the soil, making them available for producers.)

Therefore, statements 1, 2, and 3 are all correct.

The correct option is A. 1, 2 and 3 are all correct.

25. In a human being, in the face of danger:

1. Much ADH is secreted. (Incorrect, ADH (Antidiuretic Hormone) is involved in water balance, not directly in the "fight or flight" response to danger. Adrenaline/epinephrine is the primary hormone.)
2. Heart beats faster. (Correct, part of the "fight or flight" response, mediated by the sympathetic nervous system and adrenaline.)
3. Pupil opens wider. (Correct, also part of the "fight or flight" response, allowing more light to enter the eye for better vision.)

Therefore, statements 2 and 3 are correct.

The correct option is C. 2 and 3 only.