Year 11 Week 4 Quiz - Meiosis And The Digestive System

1.

A crossover in meiosis is an exchange of genetic material between:
- A.
  
  Sister chromatids of homologous chromosomes
- B.
  
  Non-sister chromatids of homologous chromosomes
- C.
  
  Sister chromatids of non-homologous chromosomes
- D.
  
  Non-sister chromatids of non-homologous chromosomes
Correct Answer
B. Non-sister chromatids of homologous chromosomes

Explanation
During meiosis, a crossover occurs when genetic material is exchanged between non-sister chromatids of homologous chromosomes. This exchange of genetic material leads to genetic recombination, which increases genetic diversity in offspring. The exchange occurs at specific points called chiasmata, where the non-sister chromatids break and rejoin, resulting in the swapping of genetic material between homologous chromosomes. This process is essential for proper segregation of chromosomes during meiosis and the creation of genetically unique gametes.

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2.

Random orientation of homologous chromosomes occurs in ________ of meiosis.
- A.
  
  Prophase I
- B.
  
  Metaphase I
- C.
  
  Prophase II
- D.
  
  Anaphase II
Correct Answer
B. Metaphase I

Explanation
During metaphase I of meiosis, homologous chromosomes line up at the equatorial plate of the cell. The orientation of the chromosomes is random, meaning that each pair of homologous chromosomes can align in different ways. This random orientation is important for genetic diversity as it allows for different combinations of chromosomes to be passed on to the daughter cells during the subsequent stages of meiosis.

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3.

Why do homologous chromosomes pair in prophase I and not in prophase II?
- A.
  
  Pairing of chromosomes requires precision and it would take too much metabolic energy to pair them twice.
- B.
  
  The kinetochores have been used up after separating the sister chromatids during meiosis I.
- C.
  
  The cells are haploid during prophase II and therefore can't pair.
- D.
  
  Meiosis I is more like mitosis than meiosis II is, and so the chromosomes pair up similarly in meiosis I and mitosis
Correct Answer
C. The cells are haploid during prophase II and therefore can't pair.

Explanation
During prophase I of meiosis, homologous chromosomes pair up to undergo crossing over, which is essential for genetic recombination. This pairing allows for the exchange of genetic material between the homologous chromosomes. However, in prophase II, the cells are already haploid because they have undergone chromosome separation during meiosis I. Since there are no homologous chromosomes left to pair with, they cannot pair in prophase II. Therefore, the correct answer is that the cells are haploid during prophase II and therefore can't pair.

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4.

The number of chromosomes in daughter cells produced by meiosis is ________ the number of chromosomes in daughter cells produced by mitosis.
- A.
  
  Diploid
- B.
  
  Triploid
- C.
  
  Half
- D.
  
  Double
Correct Answer
C. Half

Explanation
During meiosis, the number of chromosomes in daughter cells is halved compared to the number of chromosomes in the parent cell. This is because meiosis involves two rounds of cell division, resulting in the formation of four haploid daughter cells. In contrast, mitosis produces two diploid daughter cells that have the same number of chromosomes as the parent cell. Therefore, the correct answer is "half."

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5.

At the end of meiosis I, each daughter cell is:
- A.
  
  Diploid, and each chromosome consists of a single chromatid.
- B.
  
  Haploid, and each chromosome consists of a single chromatid.
- C.
  
  Haploid, and each chromosome consists of a single chromatid.
- D.
  
  Haploid, and each chromosome consists of two chromatids.
Correct Answer
D. Haploid, and each chromosome consists of two chromatids.

Explanation
At the end of meiosis I, each daughter cell is haploid, meaning it contains half the number of chromosomes compared to the parent cell. Additionally, each chromosome consists of two chromatids, which are identical copies of the DNA molecule. This is because during meiosis I, homologous chromosomes separate, resulting in the distribution of one chromosome from each pair to each daughter cell. Each of these chromosomes consists of two chromatids, which will eventually separate during meiosis II.

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6.

Which one of the following is absorbed in the gastrointestinal tract without being digested?
- A.
  
  Starch
- B.
  
  Proteins
- C.
  
  Triglycerides
- D.
  
  Vitamins
Correct Answer
D. Vitamins

Explanation
Vitamins are absorbed in the gastrointestinal tract without being digested because they are already in a form that can be easily absorbed by the body. Unlike starch, proteins, and triglycerides, which need to be broken down into smaller molecules before they can be absorbed, vitamins can be directly absorbed into the bloodstream and transported to the cells where they are needed.

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7.

If you suck on a plain piece of bread, it will begin to taste sweet after a few moments. Saliva contains the digestive enzyme ________________, which breaks down starch into ________________.
- A.
  
  Amylase; glucose
- B.
  
  Pepsin; maltose
- C.
  
  Amylase, maltose
- D.
  
  Maltase, glucose
Correct Answer
C. Amylase, maltose

Explanation
Saliva contains the digestive enzyme amylase, which breaks down starch into maltose. When you suck on a plain piece of bread, the amylase in saliva starts breaking down the starch in the bread into maltose. Maltose is a disaccharide that has a sweet taste, which is why the bread begins to taste sweet after a few moments.

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8.

If you were able to collect the chyme from the small intestine and isolate its various enzymes, most of the enzymes would have been produced by the:
- A.
  
  Gall bladder
- B.
  
  Small intestine
- C.
  
  Pancreas
- D.
  
  Stomach
Correct Answer
C. Pancreas

Explanation
The correct answer is the pancreas. The pancreas is responsible for producing and releasing many enzymes that aid in the digestion of food in the small intestine. These enzymes include amylase, lipase, and proteases, which break down carbohydrates, fats, and proteins respectively. The gall bladder stores and releases bile, which helps in the digestion of fats, but it does not produce enzymes. The small intestine does produce some enzymes, but the majority of the enzymes in the chyme would be produced by the pancreas. The stomach produces gastric juice, which contains hydrochloric acid and pepsin, but these are not the main enzymes involved in the digestion of chyme in the small intestine.

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9.

Arrange these events in the order in which they occur during fat digestion, absorption, and transport:1. chylomicrons enter lacteals2. triglycerides, phospholipids and cholesterol coated with protein3. fatty acids and glycerol packaged into micelles4. bile salts emulsify fats5. lipase digests fat
- A.
  
  1,2,4,5,3
- B.
  
  4,5,3,2,1
- C.
  
  2,5,4,3,1
- D.
  
  5,3,4,1,2
Correct Answer
B. 4,5,3,2,1

Explanation
The correct order of events during fat digestion, absorption, and transport is as follows: 4. bile salts emulsify fats, 5. lipase digests fat, 3. fatty acids and glycerol packaged into micelles, 2. triglycerides, phospholipids, and cholesterol coated with protein, and 1. chylomicrons enter lacteals. Bile salts emulsify fats to increase their surface area for lipase to act on. Lipase then breaks down the fats into fatty acids and glycerol, which are then packaged into micelles. Triglycerides, phospholipids, and cholesterol are then coated with proteins to form chylomicrons, which enter lacteals for transport.

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10.

Which of the following parts of the digestive system would contain a fluid that lacks digestive enzymes?
- A.
  
  Stomach
- B.
  
  Duodenum
- C.
  
  Gall bladder
- D.
  
  Pancreas
Correct Answer
C. Gall bladder

Explanation
The gall bladder would contain a fluid that lacks digestive enzymes. The gall bladder stores bile, which is produced by the liver and aids in the digestion and absorption of fats. Bile does not contain digestive enzymes, but it helps in the emulsification and breakdown of fats into smaller droplets, making it easier for enzymes to act upon them.

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Year 11 Week 4 Quiz - Meiosis And The Digestive System

A crossover in meiosis is an exchange of genetic material between:

Random orientation of homologous chromosomes occurs in ________ of meiosis.

Why do homologous chromosomes pair in prophase I and not in prophase II?

The number of chromosomes in daughter cells produced by meiosis is ________ the number of chromosomes in daughter cells produced by mitosis.

At the end of meiosis I, each daughter cell is:

Which one of the following is absorbed in the gastrointestinal tract without being digested?

If you suck on a plain piece of bread, it will begin to taste sweet after a few moments. Saliva contains the digestive enzyme ________________, which breaks down starch into ________________.

If you were able to collect the chyme from the small intestine and isolate its various enzymes, most of the enzymes would have been produced by the:

Arrange these events in the order in which they occur during fat digestion, absorption, and transport:1. chylomicrons enter lacteals2. triglycerides, phospholipids and cholesterol coated with protein3. fatty acids and glycerol packaged into micelles4. bile salts emulsify fats5. lipase digests fat

Which of the following parts of the digestive system would contain a fluid that lacks digestive enzymes?

If you suck on a plain piece of bread, it will begin to taste sweet after a few moments. Saliva contains the digestive enzyme , which breaks down starch into .