Unit 3A review

What is the main difference between mitosis and meiosis?

• The main difference between mitosis and meiosis is that mitosis results in two identical daughter cells, while meiosis results in four genetically diverse daughter cells.

• Mitosis results in four genetically diverse daughter cells, while meiosis results in two identical daughter cells.

• Mitosis and meiosis are the same process.

• Mitosis and meiosis both result in two identical daughter cells.

Answer explanation

The main difference between mitosis and meiosis is the number of daughter cells produced. Mitosis results in two identical daughter cells, while meiosis results in four genetically diverse daughter cells.

Which process involves the replication of DNA?

• DNA synthesis

• DNA transcription

• DNA translation

• DNA replication

Answer explanation

DNA replication is the process of copying DNA to produce an identical copy. It is essential for cell division and inheritance of genetic information.

What is a genetic mutation?

• A genetic mutation is a change in the RNA sequence.

• A genetic mutation is a change in the cell structure.

• A genetic mutation is a change in the protein sequence.

• A genetic mutation is a change in the DNA sequence.

Answer explanation

A genetic mutation is a change in the DNA sequence. It is a alteration in the genetic code that can lead to variations in traits and diseases.

Which of the following is an example of a genetic disease?

• Malaria

• Influenza

• Tuberculosis

• Cystic fibrosis

Answer explanation

Cystic fibrosis is a genetic disease.

What is gene linkage?

• The process of creating new genes through genetic recombination

• The tendency of certain genes to be inherited together because they are located near each other on the same chromosome.

• The process of copying genes from one chromosome to another

• The tendency of certain genes to be inherited separately because they are located far apart on different chromosomes

Answer explanation

Gene linkage refers to the tendency of certain genes to be inherited together because they are located near each other on the same chromosome.

What is the pattern of inheritance for hemophilia?

• Y-linked

• Autosomal recessive

• X-linked recessive

• Autosomal dominant

Answer explanation

Hemophilia follows an X-linked recessive pattern of inheritance, where the gene responsible for the condition is located on the X chromosome. This means that the condition is more commonly seen in males, who have one X chromosome, while females are usually carriers.

During which phase of the cell cycle does DNA replication occur?

• S phase

• G2 phase

• G1 phase

• M phase

Answer explanation

DNA replication occurs during the S phase of the cell cycle.

What is the purpose of meiosis?

• The purpose of meiosis is to produce gametes with double the number of chromosomes for sexual reproduction.

• The purpose of meiosis is to produce gametes with half the number of chromosomes for sexual reproduction.

• The purpose of meiosis is to produce gametes with the same number of chromosomes for sexual reproduction.

• The purpose of meiosis is to produce somatic cells with half the number of chromosomes for asexual reproduction.

Answer explanation

Meiosis produces gametes with half the number of chromosomes for sexual reproduction.

Which of the following is an example of a recessive genetic disorder?

• Cystic fibrosis

• Sickle cell anemia

• Down syndrome

• Huntington's disease

Answer explanation

Cystic fibrosis is an example of a recessive genetic disorder. It is caused by mutations in the CFTR gene and affects the lungs, pancreas, and other organs. The inheritance pattern is autosomal recessive, meaning both parents must carry a mutated gene for the child to be affected.

What is the probability of a carrier mother and a carrier father having a child with hemophilia?

• 50% or 1 in 2

• 10% or 1 in 10

• 75% or 3 in 4

• 25% or 1 in 4

Answer explanation

The probability of a carrier mother and a carrier father having a child with hemophilia is 25% or 1 in 4. This is because both parents must pass on the recessive gene for hemophilia to their child.