PRMS 8th Grade Science - DNA Flashcards

Questions and Answers

What are chromosomes made out of?

DNA and proteins

What are nucleotides?

Nucleotides are the building blocks of DNA, each consisting of a sugar, a phosphate, and a nitrogen base.

What are purines?

Adenine and Guanine

What are pyrimidines?

Thymine and Cytosine Signup and view all the answers

What kind of information is contained in DNA?

The blueprint of the body Signup and view all the answers

What is a double helix?

A twisted ladder structure of DNA Signup and view all the answers

Which two scientists built a model that showed how the double helix structured DNA?

James Watson and Francis Crick Signup and view all the answers

What makes up a nucleotide?

A nitrogen base, a sugar, and a phosphate group Signup and view all the answers

Which nitrogen bases always bond together?

Adenine and Thymine Signup and view all the answers

Who was the first scientist to discover nucleic acids?

Friedrich Miescher Signup and view all the answers

What are the two types of nucleic acid?

DNA and RNA Signup and view all the answers

Where is RNA found?

In the nucleus Signup and view all the answers

What is the function of DNA?

Controls the production of proteins within the cell Signup and view all the answers

What are the three parts of a nucleotide?

A nitrogen base, a sugar, and a phosphate group Signup and view all the answers

What is the spiral shape of DNA referred to as?

Double helix Signup and view all the answers

What two things make up the backbone of a DNA molecule?

Phosphate and deoxyribose sugar Signup and view all the answers

What are the steps or rungs of the DNA molecule?

Pairs of nitrogen bases Signup and view all the answers

What are the four nitrogenous bases that make up the rungs or 'the teeth' of the DNA double helix?

Adenine, Cytosine, Thymine, and Guanine Signup and view all the answers

Name the two scientists who discovered the structure of DNA.

Rosalind Franklin and Maurice Wilkins Signup and view all the answers

What is the 'Base-Pair Rule'?

Adenine pairs with Thymine and Guanine pairs with Cytosine Signup and view all the answers

What holds the nitrogen bases together in a real DNA molecule?

Sugar molecules Signup and view all the answers

Describe the shape of a DNA model.

It looks like a ladder. Signup and view all the answers

Why do you think Adenine always pairs with Thymine and Guanine always pairs with Cytosine?

They are chemically attracted to each other. Signup and view all the answers

If you were to make a model of RNA, how would it compare to your DNA model?

RNA would look like a half DNA model but single stranded and with Uracil instead of Thymine. Signup and view all the answers

How does DNA replicate itself during Interphase?

By making an exact copy. Signup and view all the answers

What is the full name of DNA?

Deoxyribonucleic Acid Signup and view all the answers

What is a gene?

A segment of DNA Signup and view all the answers

Where in the cell are chromosomes located?

In the nucleus Signup and view all the answers

DNA can be found in what two organelles?

Mitochondria and chloroplasts Signup and view all the answers

What is the shape of DNA?

Shaped like a twisted ladder Signup and view all the answers

What are the sides of the DNA ladder made of?

Alternating sugar and phosphate molecules Signup and view all the answers

What sugar is found in DNA?

Deoxyribose Signup and view all the answers

What sugar is found in RNA?

Ribose Signup and view all the answers

How do the bases bond together?

A bonds with T and G bonds with C Signup and view all the answers

What are the two purines in DNA?

Adenine and Guanine Signup and view all the answers

What is DNA made of?

Repeating units called nucleotides Signup and view all the answers

Why is RNA necessary to act as a messenger?

Because the code cannot be taken directly from the DNA. Signup and view all the answers

Where in the cell are proteins made?

In the ribosomes Signup and view all the answers

How do some cells become brain cells and others become skin cells when the DNA in all cells is exactly the same?

Cells can block out other directions. Signup and view all the answers

What is the nucleus?

The control center of the cell Signup and view all the answers

What are chromosomes?

Microscopic, threadlike strands composed of DNA Signup and view all the answers

What is DNA?

The chemical that genes and chromosomes are made of Signup and view all the answers

What are proteins?

The building blocks for an organism Signup and view all the answers

What are genes?

Segments of DNA that code for a particular protein Signup and view all the answers

Where is DNA found?

In the nucleus and organelles like mitochondria and chloroplasts Signup and view all the answers

How are the two sides of the DNA ladder held together?

Loosely by hydrogen bonds Signup and view all the answers

What happens when DNA replicates?

DNA makes a copy of itself for cell division. Signup and view all the answers

The nucleus is the control center of the cell. What does it do?

Controls cell activities through DNA. Signup and view all the answers

What is messenger RNA?

A chemical that reads DNA in the nucleus. Signup and view all the answers

How does messenger RNA compare to DNA?

It is a single strand and has Uracil instead of Thymine. Signup and view all the answers

What does RNA stand for?

Ribonucleic Acid Signup and view all the answers

Why is DNA called the 'Blueprint of Life'?

Because it tells the cell how to build the organism. Signup and view all the answers

What are introns or junk DNA?

Regions of DNA that do not code for proteins. Signup and view all the answers

What are exons?

Sections of DNA that actually code for proteins. Signup and view all the answers

Study Notes

Chromosomes and DNA Structure

Chromosomes consist of DNA and proteins, forming the genetic material within cells.
The full name of DNA is Deoxyribonucleic Acid; its structure resembles a twisted ladder or double helix.
DNA is made from repeating units called nucleotides, which include a nitrogen base, a sugar (deoxyribose), and a phosphate group.
The "backbone" of a DNA molecule is composed of alternating sugar and phosphate units.
There are four nitrogen bases in DNA: Adenine (A), Thymine (T), Cytosine (C), and Guanine (G).

Nucleotide Information

A nucleotide includes three components: a nitrogen base, a sugar, and a phosphate group.
Nitrogen bases bond in specific pairs: Adenine pairs with Thymine, and Guanine pairs with Cytosine, following the "Base-Pair Rule."
The sequence of nitrogen bases in DNA encodes genetic information necessary for building proteins.

RNA Characteristics

RNA, or Ribonucleic Acid, differs from DNA by being single-stranded and containing Uracil (U) instead of Thymine (T).
RNA is found mainly in the nucleus and acts as a messenger, relaying instructions from DNA to ribosomes for protein synthesis.

Key Scientists and Discoveries

The double helix structure of DNA was identified by James Watson and Francis Crick, with contributions from Rosalind Franklin and Maurice Wilkins.
Friedrich Miescher was the first to discover nucleic acids, laying groundwork for DNA research.

Genes and Proteins

A gene is a specific segment of DNA that codes for a particular protein, influencing various traits.
Proteins serve as the building blocks of organisms and are produced based on the instructions encoded in DNA.
Some regions of DNA that do not code for proteins are referred to as introns or "junk DNA," while coding segments are called exons.

DNA Replication and Function

DNA replicates during Interphase through a process of making exact copies to ensure new cells inherit accurate genetic information.
The nucleus functions as the control center of the cell, managing activities through the genetic instructions contained in DNA.
Cells can block the expression of certain genes, allowing different cell types (e.g., brain cells, skin cells) to develop despite having identical DNA.

Overall Significance

DNA is described as the "Blueprint of Life" due to its role in defining how organisms develop and function.
Understanding DNA and RNA functionality is crucial for studying genetics, heredity, and biological processes.

Studying That Suits You

Use AI to generate personalized quizzes and flashcards to suit your learning preferences.

Description

Test your knowledge of DNA with these flashcards designed for 8th grade science. Learn the components of chromosomes and nucleotides, and explore their roles in genetics. A great way to reinforce your understanding of the molecular basis of life.