Chromosome Structure and Gene Location

Which structure holds genetic information inside the nucleus?

• Ribosome

• Chromosome

• Centriole

• Golgi apparatus

Answer explanation

The chromosome is the structure that holds genetic information inside the nucleus. It is composed of DNA and proteins, making it essential for storing and transmitting genetic material during cell division.

What are chromosomes primarily made of?

• Proteins and DNA

• Lipids and proteins

• Sugars and fats

• RNA and proteins

Answer explanation

Chromosomes are primarily made of proteins and DNA. The DNA carries genetic information, while proteins help in packaging and organizing the DNA into a compact structure, making this the correct choice.

What is the location on a chromosome where a gene is found called?

• Codon

• Locus

• Nucleolus

• Centriole

Answer explanation

The location on a chromosome where a gene is found is called a locus. This term specifically refers to the fixed position of a gene or genetic marker on a chromosome.

What structure joins two sister chromatids together?

• Telomere

• Centromere

• Histone

• Ribosome

Answer explanation

The centromere is the structure that joins two sister chromatids together, ensuring proper separation during cell division. It plays a crucial role in the movement of chromatids to opposite poles of the cell.

Which part of the chromosome protects the ends from deterioration?

• Centromere

• Telomere

• Chromatid

• Histone

Answer explanation

The telomere is the part of the chromosome that protects the ends from deterioration. It prevents the loss of important genetic information during cell division, unlike the centromere, chromatid, or histone.

Where are genes specifically located in a chromosome?

• In the cytoplasm

• On specific loci along the DNA strand

• Only at the telomeres

• Only on ribosomes

Answer explanation

Genes are located on specific loci along the DNA strand of a chromosome, which allows them to be organized and expressed properly. The other options do not accurately describe the location of genes.

How many chromatids does a duplicated chromosome have?

• One

• Two

• Three

• Four

Answer explanation

A duplicated chromosome consists of two identical sister chromatids, which are joined at the centromere. Therefore, the correct answer is two.

What is the function of histone proteins in chromosomes?

• To replicate DNA

• To package and organize DNA

• To synthesize RNA

• To repair mutations

Answer explanation

Histone proteins play a crucial role in packaging and organizing DNA within chromosomes, allowing for efficient storage and regulation of genetic material. This makes 'To package and organize DNA' the correct choice.

The arms of a chromosome extend from:

• The nucleolus

• The centromere

• The spindle fibers

• The ribosomes

Answer explanation

The arms of a chromosome extend from the centromere, which is the region where the two sister chromatids are joined. This structure is crucial for proper chromosome movement during cell division.

What term describes the thread‑like form of DNA and proteins seen in a non‑dividing cell?

• Chromatin

• Chromosome

• Centromere

• Codon

Answer explanation

The term 'chromatin' refers to the thread-like structure of DNA and proteins in a non-dividing cell, allowing for the organization and regulation of genetic material. 'Chromosome' refers to condensed chromatin during cell division.