Question 1

When the wrong base is inserted during DNA replication,a(n)________ error occurs.

Accepted Answer

The answer of When the wrong base is inserted during...

Question 2

Housekeeping genes

Accepted Answer

Housekeeping genes are essential genes that are expressed in most or all cells of an organism. They are involved in basic cellular functions such as metabolism and cell maintenance.

Note: A, B, and D are incorrect because they do not accurately describe the role of housekeeping genes.

Question 3

During DNA replication,the enzyme ________ builds a new strand of DNA while using the old strand of DNA as a template.

Accepted Answer

The answer of During DNA replication,the enzyme ________ builds a...

Question 4

DNA ________ results in the copying of a DNA molecule.

Accepted Answer

The answer of DNA ________ results in the copying of...

Question 5

Why do chromosomes only reach their highest level of compaction during mitosis and meiosis?

Accepted Answer

During mitosis and meiosis, the chromosomes need to be tightly compacted to ensure they are properly distributed to each daughter cell. If the chromosomes were not compacted, they could become entangled and not properly sorted, leading to potential genetic disorders.

Answer: C 
 The compacting of chromosomes during mitosis and meiosis helps them fit into the nucleus of the daughter cells. This is important, as each daughter cell needs to have the correct number of chromosomes to properly function.

Therefore, both choice B and C are correct.

Question 6

DNA consists of two twisted strands of ________.

Accepted Answer

The answer of DNA consists of two twisted strands of...

Question 7

If their food source changes from lactose to arabinose,bacteria turn off their genes for lactose enzymes and turn on their genes for arabinose enzymes.Why don't bacteria express the genes for both lactose and arabinose enzymes all the time?

Accepted Answer

Bacteria turn off their genes for lactose enzymes and turn on their genes for arabinose enzymes in response to changes in their food source because it is more energy-efficient and resource-efficient to produce only the necessary enzymes. Producing both sets of enzymes all the time would be a waste of energy and resources.

Question 8

The "rungs" in the DNA "ladder" consist of ________ pairs.

Accepted Answer

The answer of The "rungs" in the DNA "ladder" consist...

Question 9

When compared,the nucleotide sequences of different individuals are________.

Accepted Answer

The answer of When compared,the nucleotide sequences of different individuals...

Question 10

Which of the following is NOT true? Organisms turn genes on and off

Accepted Answer

Genes being turned on and off is a complex process that allows organisms to respond to environmental stimuli, undergo developmental changes, and carry out specialized functions in different cell types. However, genes being turned on and off cannot result in switching from prokaryotic to eukaryotic status, as it involves fundamental differences in cell structure and organization.

Question 11

One parent is a carrier for a recessive disease.The other parent is not a carrier and does not have the disease.Is it necessary for the fetus to undergo prenatal genetic screening to determine if she has the disease?

Accepted Answer

If one parent is a carrier for a recessive disease and the other parent is not a carrier, there is a 50% chance that the fetus will be a carrier for the disease and a 50% chance that they will not be a carrier. If the fetus is a carrier, they will not have the disease themselves. Prenatal genetic screening would only identify if the fetus inherited the recessive gene, but it wouldn't tell if the fetus will be affected by the disease or will only be a carrier. Therefore, it is not necessary to undergo prenatal genetic screening for this particular case.

Question 12

How can a cell contain DNA molecules that are much longer than the cell?

Accepted Answer

DNA is packaged in a tightly coiled and compacted form through a process called supercoiling. This allows it to fit within the nucleus of a cell, even though it is much longer than the cell itself.

Question 13

When Francis Collins described the Human Genome Database as a "shop manual," he meant that the human genome contains

Accepted Answer

Collins meant that the human genome contains instructions for making all the RNAs and proteins that make up a human, similar to how a shop manual contains instructions for building and repairing a mechanical object.

Question 14

Which of the following might lead to a genome copy number variant in which the individual has only one copy of a gene instead of the normal two copies?

Accepted Answer

Chromosomal deletion, also known as deletion mutation, can result in the loss of one or more genes due to the absence of a section of the chromosome. This can cause a genome copy number variant in which the individual has only one copy of a gene instead of the normal two copies.

Question 15

The following table shows which of these four genes are on or off in three different cell types.  Why is the expression of the rRNA gene so different from the expression of the other genes in the table?

Accepted Answer

The expression of the rRNA gene is different because it is required for the proper functioning of all cells, while the products of the other genes are only essential to the function of one cell type. This suggests that rRNA is needed in large quantities across all cell types, whereas the other genes are needed in specific cell types or situations.

Question 16

When the breast cancer genes,BRCA1 and BRCA2,are mutated,damaged DNA in the cell is not corrected.Based on this information,the BRCA genes produce ________ proteins.

Accepted Answer

The answer of When the breast cancer genes,BRCA1 and BRCA2,are...

Question 17

To convert genetic information into a phenotype,the process labeled with the letter D in this diagram of the process of gene flow in a cell requires ________.

Accepted Answer

The answer of To convert genetic information into a phenotype,the...

Question 18

One level of DNA packing involves the DNA being wound around

Accepted Answer

One level of DNA packing involves the DNA being wound around histone proteins to form nucleosomes. This helps to condense the DNA and allows for more efficient packing into the nucleus of the cell. RNA molecules, cytoplasmic organelles, and translation enzymes are not involved in this process of DNA packing.

Question 19

Scientists discovered that Otzi,the 5,200-year-old frozen Copper Age man found in the Alps in 1991,had a variable DNA sequence called K.What caused the variations in this DNA sequence?

Accepted Answer

Variations in DNA sequence are caused by mutations, which are changes in the nucleotide sequence of DNA.

Question 20

The enzymes involved in ATP synthesis in the mitochondria are likely to be encoded by ________ genes.

Accepted Answer

The enzymes involved in ATP synthesis are part of the mitochondrial respiratory chain, which is essential for ATP production. These enzymes are likely encoded by housekeeping genes, which are genes that are expressed in all cells and are required for basic cellular functions.

Quiz 11: DNA and Genes