Keystone Biology Module 2 Review

A student looking through a microscope records observations about a cell. Which stage of the cell cycle has the student described?

• prophase

• anaphase

• interphase

• telophase

Answer explanation

The events listed occur during prophase of the cell cycle.

Tags

NGSS.HS-LS1-4

Before cellular division, the cell must duplicate its DNA so that daughter cells will contain complete copies of the DNA. Which characteristic of DNA makes it most suitable as a molecule for this role?

• DNA is located in the nucleus.

• DNA is a large macromolecule.

• DNA is made of repeating sugar-phosphate subunits.

• DNA is made of two strands of complementary nucleotides.

Answer explanation

The complementary nature of the two strands allows each strand to serve as a template during replication.

Tags

NGSS.HS-LS1-4

Which statement best explains how organisms accomplish passing on traits to their offspring?

• Traits are acquired when parents care for their offspring.

• Offspring inherit traits when DNA is replicated during mitosis.

• Traits are inherited by the transfer of genetic material from parent to offspring.

• Offspring acquire traits when cells become specialized for certain functions.

Answer explanation

DNA is the genetic material transferred from parent to offspring, and it codes for an organism's inherited traits.

Tags

NGSS.HS-LS3-1

During the cell division cycle, chromosome segments from two homologous chromosomes exchange places. Which result is most likely to occur following this cycle?

• Genetic material will be lost.

• The number of chromosomes will increase.

• The total number of genes in the cell will decrease.

• A change in gene location will occur on both chromosomes.

Answer explanation

Translocation is an exchange of pieces of homologous chromosomes.

Tags

NGSS.HS-LS3-2

Which statement best describes how organisms use DNA and amino acids to synthesize a protein?

• DNA is transcribed into mRNA, which is translated by the ribosome to produce an amino acid chain.

• DNA is translated into mRNA, which is transcribed by the ribosomes to produce an amino acid chain.

• Amino acids are transcribed into mRNA, which is translated in the nucleus to produce a molecule of DNA.

• Amino acids are translated into mRNA, which is transcribed in the nucleus to produce a molecule of DNA.

Answer explanation

The two key stages of protein synthesis are DNA being transcribed into mRNA (transcription), which is then translated by the ribosome to produce an amino acid chain (translation).

Tags

NGSS.HS-LS1-1

Original RNA Sequence of Organism

AUG--GCU--UGU

Which mutation would most likely affect the organism's phenotype?

• AUG--GCC--UGU

• AUG--GCG--UGU

• AUG--GCU--UGA

• AUG--GCU--UGC

Answer explanation

The original sequence codes for Cys, while the mutated sequence codes for a stop. This could result in a change in the organism's phenotype.

Tags

NGSS.HS-LS3-2

Two closely related shrimp species have habitats and niches that partially overlap. Which factor most likely caused the divergence of the shrimp into separate species?

• reproductive isolation

• reduction of food supply

• a series of rapid mutations

• large initial population size

Answer explanation

Shrimp that occupy separate habitats and niches are more likely to reproduce with nearby shrimp, eventually leading to speciation.

Tags

NGSS.HS-LS4-2

NGSS.HS-LS4-4

At a point in the cell cycle, chromosomes have aligned near the middle of a cell. Which sequence of events will the cell need to complete to produce two identical daughter cells.

• anaphase→telophase→cytokinesis

• anaphase II→telophase II→cytokinesis II

• prophase→metaphase→anaphase

• metaphase II→anaphase II→telophase II

Answer explanation

Chromosomes align during metaphase, which is followed by anaphase, telophase, and cytokinesis.

Tags

NGSS.HS-LS1-4

Which student correctly compared the outcomes of meiosis and mitosis?

• student 1

• student 2

• student 3

• student 4

Answer explanation

Meiosis produces four haploid daughter cells, and mitosis produces two diploid daughter cells.

Tags

NGSS.HS-LS1-4

The genetic event shown in the diagram can occur during meiosis. Which statement best describes this type of event?

• Gene sequences that are identical are replicated and added to the homologous chromosomes.

• Sections of DNA between homologous chromosomes are exchanged, decreasing genetic diversity.

• Segments of homologous chromosomes are exchanged, resulting in cells that will be genetically different.

• The traits from two sections of the same DNA strand are altered, resulting in the production of a new species.

Answer explanation

The chromosomes exchange segments during crossing-over, which results in recombinant chromosomes. This process increases genetic diversity.

Tags

NGSS.HS-LS3-2