The correct options are B and C.
Within a eukaryotic cell, DNA is packaged around proteins (histones) within the nucleus. The phosphate groups in the DNA molecule do indeed carry a negative charge, contributing to the overall structure and function of DNA.
However, DNA is not surrounded by two separate phospholipid membranes; instead, it is enclosed by the nuclear envelope, which separates the nucleus from the cytoplasm.
DNA, or deoxyribonucleic acid, is a fundamental molecule that carries genetic information in eukaryotic cells, among others.
To describe the structure and location of DNA within a eukaryotic cell, let's analyze each statement:
A. DNA is surrounded by two separate phospholipid membranes within the cell.
This statement is not accurate. In a eukaryotic cell, DNA is primarily located within the nucleus, which is enclosed by a double membrane called the nuclear envelope.
However, this double membrane does not directly surround the DNA itself. The DNA is found within the nucleus, while the nuclear envelope separates the nucleus from the cytoplasm. The structure that surrounds DNA directly is a complex of proteins called chromatin.
B. DNA is packaged around proteins within the nucleus.
This statement is correct. DNA is not a loose, linear strand within the nucleus; instead, it is highly organized and tightly packaged around proteins called histones to form a structure known as chromatin.
This packaging is essential to fit the long DNA molecules into the small nucleus and regulate gene expression. The DNA-histone complex makes up the basic unit of chromatin, known as the nucleosome.
C. The phosphate group of the nucleotides within DNA has a negative charge.
This statement is accurate. The phosphate group (PO4-) in the DNA molecule carries a negative charge due to its structure. The backbone of DNA consists of alternating sugar (deoxyribose) and phosphate groups, forming a negatively charged, hydrophilic backbone.
The negative charge of the phosphate groups plays a crucial role in the structure and function of DNA, as it helps to repel the negatively charged backbones of adjacent DNA strands, allowing them to twist into the characteristic double helix shape.
The correct options based on the provided statements are:
B. DNA is packaged around proteins within the nucleus.
C. The phosphate group of the nucleotides within DNA has a negative charge.
The complete question is here:
DNA structural description Which of the following describes DNA within a eukaryotic cell? (Select all that apply) Check All That Apply
A. DNA is surrounded by two separate phospholipid membranes within the cell.
B. DNA is packaged around proteins within the nucleus.
C. The phosphate group of the nucleotides within DNA have a negative charge.