What do you know about life's most essential building block? Take our quiz on human body cells!
How does your body make new cells? Where did the term "cell" originate? What are the different parts of a cell, and what are their jobs? Take the quiz to see how much you know about these tiny yet vital components.start quiz
Question 1 of 20
Who coined the term "cell"?
... Robert Hooke first observed cork cells in 1665. The numerous small squares reminded him of monastery rooms or "cells."
Question 2 of 20
Which of the following is NOT a basic component of cell theory?
... Most, but not all, cells have nuclei. For instance, red blood cells do not.
Question 3 of 20
What is the difference between the two basic categories of cells: prokaryotes and eukaryotes?
... Prokaryotes, such as bacteria, are single-celled organisms that have no nuclear membrane. They were the first form of life on earth.
Question 4 of 20
Stem cells are important because they ________.
... Stem cells are central to regenerative medicine because they can change into other cells, such as for bone or muscle. Consequently, stem cells are vital to research into and treatment of diseases such as Parkinson's and cancer.
Question 5 of 20
Within a cell, the primary responsibility of mitochondria is _______.
... Mitochondria represent the "power house" of the cell, producing ATP, the cell's chemical energy.
Question 6 of 20
What is one reason viruses are not classified as cells?
... Unlike cells, viruses cannot reproduce on their own; they must have a host.
Question 7 of 20
Cell replication occurs during the process of _________, resulting in identical cells.
... During mitosis, a cell divides and creates two daughter cells.
Question 8 of 20
Red blood cells are produced in the _____.
... Red blood cells, which help carry oxygen throughout the body, are produced in bone marrow. It takes about seven days for a red blood cell to develop.
Question 9 of 20
About 100 _____ cells are in an adult human body.
... An adult has about 100 trillion cells, including somatic (body), germ (egg or sperm) and stem cells.
Question 10 of 20
The primary difference between animal and plant cells is that _______.
... A plant cell has a cell wall that provides additional structure and protection for the organism.
Question 11 of 20
Communication among nerve cells requires _______.
... Chemicals called neurotransmitters complete the pathways among neurons (nerve cells). There are about one hundred different neurotransmitters, including dopamine, histamine and melatonin.
Question 12 of 20
A cell must have _______ that allow(s) chemical reactions to occur.
... Enzymes are essential within a cell, speeding up the chemical reactions that occur. Enzymes include lactase and tryptophan.
Question 13 of 20
The antibiotic penicillin attacks the _______ of bacteria.
... Penicillin interferes with bacteria's ability to properly make cell walls. The walls are fragile and burst easily, killing the bacteria.
Question 14 of 20
The study of the structure and function of cells is called _______.
... Cytologists use microscopes and stains to study cells and tissues of organisms.
Question 15 of 20
Water, carbon dioxide and oxygen all commonly move in and out of cells through _______.
... Several types of molecules use simple diffusion to move from areas of higher concentration to areas of lower concentration.
Question 16 of 20
Egg and sperm cells are produced by the process of ________.
... After the process of meiosis, each sperm or egg has half the usual number of chromosomes. That facilitates the combination of chromosomes that takes place during fertilization, so the resulting zygote has obtained half of its genetic material from each parent.
Question 17 of 20
The first synthetic cell was based on the genome of a _______.
... In 2010, a lab-created bacterial genome was placed inside a cell and took over that cell.
Question 18 of 20
New skin cells are made in the bottom layer of skin, taking about _____ to move to the top layer.
... Your skin completely replaces itself about once a month.
Question 19 of 20
An elevated number of white blood cells can indicate _________.
... White blood cells are part of the immune system, so they increase in the presence of infection. Their numbers can also be affected by drugs designed to stimulate their production. In addition, since they are produced in the bone marrow, an exceptionally high quantity may indicate a marrow disease.
Question 20 of 20
About how many different kinds of cells are there in the human body?
... There are about 200 different types of cells in our bodies, varying from rather general (e.g., muscle cells) to highly specific (e.g., tooth enamel-making cells).
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