DNA, Genes and Chromosomes

Which organelle contains chromosomes that are made of DNA?

• Nucleus

• Mitochondria

• Cell membrane

• Cytoplasm

What are histones?

• Proteins that DNA wraps around to help form a chromosome.

• A type of nitrogenous base.

• A DNA sub-unit comprising a phosphate, sugar and nitrogenous base.

• The opposite of herstones.

What is the main structural component that forms the backbone of a DNA molecule?

• Sugar-phosphate backbone

• Nitrogenous base

• Protein chain

• Lipid bilayer

In the molecule pictured, name the components labelled A, B and C in the correct order.

• Phosphate, Base, Sugar

• Phosphate, Sugar, Base

• Adenine, Base, Cytosine

• Adenine, Thymine, Cytosine

What is the name given to each section of a DNA molecule that consists of a phosphate/sugar backbone and a base?

• Nucleotide

• Chromosome

• Ribosome

• Polymerase

Why is the covalent bond important in the structure of a DNA strand?

• It allows DNA strands to separate easily.

• It provides strong connections between nucleotides, forming a stable DNA strand.

• It makes DNA soluble in water.

• It helps DNA interact with proteins.

What are the four nitrogenous bases present in DNA?

• Adenine, Thymine, Guanine, Cytosine

• Adenine, Thymine, Guanine, Uracil

• Adenine, Thymine, Guanine, Ribose

• Adenine, Thymine, Guanine, Glucose

Which type of bond is formed between complementary bases in DNA?

• Strong covalent bonds

• Ionic bonds

• Weak hydrogen bonds

• Metallic bonds

Which base always pairs with Adenine in DNA?

• Guanine

• Cytosine

• Thymine

• Uracil

Which base always pairs with Guanine in DNA?

• Thymine

• Cytosine

• Adenine

• Uracil