Question

Prokaryotes contain a ________chromosome, and eukaryotes contain ________ chromosomes. a. single-stranded circular; single-stranded linear b. single-stranded linear; single-stranded circular c. double-stranded circular; double-stranded linear d. double-stranded linear; double-stranded circular

Short answer

Answer: Prokaryotes contain a double-stranded circular chromosome, while eukaryotes contain multiple double-stranded linear chromosomes.

Step-by-step solution

Understand the types of cells

Prokaryotes are unicellular organisms that lack a nucleus and membrane-bound organelles, while eukaryotes can be unicellular or multicellular and have a nucleus and membrane-bound organelles.

Identify the genetic material in prokaryotes

Prokaryotes have a single large, circular DNA molecule called a chromosome. This chromosome is double-stranded, meaning it has two complementary strands of DNA.

Identify the genetic material in eukaryotes

Eukaryotes have multiple linear chromosomes, which are also double-stranded, contained within the nucleus.

Match statements with the options and select the correct answer

By matching our statements: - Prokaryotes contain a double-stranded circular chromosome - Eukaryotes contain multiple double-stranded linear chromosomes Option (c) aligns with these statements, so the correct answer is: c. double-stranded circular; double-stranded linear

Key concepts

Prokaryotic Cells

Prokaryotic cells are the simplest form of life. They are mainly characterized by their lack of a true nucleus and membrane-bound organelles. Instead, prokaryotic cells have a nucleoid region where genetic material is found. This makes them quite different from more complex cells like eukaryotic cells.
Prokaryotes are generally unicellular and include organisms like bacteria and archaea. They have a simple cell structure, which is suitable for their roles in various ecosystems. Prokaryotic cells reproduce mostly through binary fission, a process where a single cell divides into two identical cells.
A key aspect of prokaryotes is their single circular chromosome. This chromosome is a double-stranded DNA molecule, and it floats freely in the cell's cytoplasm, unlike the DNA in eukaryotes, which is enclosed within a nucleus. The circular structure of their chromosome is efficient for their replication needs and supports their simple but effective lifestyle.

Eukaryotic Cells

Eukaryotic cells are more complex than prokaryotic cells, featuring a nucleus that houses their DNA in the form of multiple linear chromosomes. These cells are found in a wide range of organisms, including animals, plants, fungi, and protists.
The defining feature of eukaryotic cells is their membrane-bound organelles, such as the mitochondria, endoplasmic reticulum, and the Golgi apparatus. These organelles play specific roles that contribute to the overall functioning of the cell, allowing for more specialized tasks in multicellular organisms.
Eukaryotic cells can reproduce either sexually through meiosis or asexually through mitosis. Both processes ensure the accurate replication and distribution of chromosomes, maintaining genetic stability in the resulting cells. Their linear chromosomes are organized into chromatin and are neatly packed within the nucleus, which is crucial for the intricate processes of gene expression and regulation.

Chromosomes

Chromosomes are structures that hold the genetic blueprint of life. They consist of DNA and proteins and are critical for cell division, determining the genetic makeup of organisms.
Prokaryotic Chromosomes:
Prokaryotic cells have a single circular chromosome, which is relatively simple in structure. This circular chromosome is essential for the survival and reproduction of the cell, as it carries all the genetic information needed for the organism's life processes. It's not just a matter of shape — the circular nature simplifies the replication process, ensuring rapid and efficient cell division.
Eukaryotic Chromosomes:
In eukaryotic cells, chromosomes are linear and much more numerous, varying from a few to hundreds. These chromosomes contain more sophisticated DNA organization, involving histones and other proteins that help package and regulate the DNA. These complex structures assist in managing the vast amounts of genetic material, coordinating gene expression, and facilitating the precise segregation of chromosomes during cell division.