Questions and Answers
What stores information in a cell?
DNA
In what way is DNA like a book?
DNA has stored information that can be copied and passed on
Which of the following is a nucleotide found in DNA?
deoxyribose + phosphate group + cytosine
Because of base pairing in DNA, the percentage of what is about equal to the percentage of pyrimidine?
Signup and view all the answers
How did Rosalind Franklin contribute to the understanding of DNA?
Signup and view all the answers
Which scientist(s) figured out that the shape of a DNA molecule was a double helix?
Signup and view all the answers
What is the chronological order of the important discoveries in the structure of DNA?
Signup and view all the answers
Which base forms a pair with thymine?
Signup and view all the answers
What did Rosalind Franklin contribute to the effort to identify the structure of DNA?
Signup and view all the answers
DNA replication results in how many DNA molecules?
Signup and view all the answers
During DNA replication, a DNA strand that has the bases CTAGGT produces a strand with what bases?
Signup and view all the answers
In eukaryotes, DNA is located where?
Signup and view all the answers
In both prokaryotes and eukaryotes, DNA replication happens when?
Signup and view all the answers
RNA contains what type of sugar?
Signup and view all the answers
These are found in both DNA and RNA.
Signup and view all the answers
RNA is usually single stranded.
Signup and view all the answers
This type of RNA brings the information in the genetic code from the nucleus to other parts of the cell.
Signup and view all the answers
This is true of eukaryotic DNA.
Signup and view all the answers
These molecules are involved in protein synthesis.
Signup and view all the answers
From which molecules are mRNA molecules transcribed?
Signup and view all the answers
What is produced during transcription?
Signup and view all the answers
During eukaryotic transcription, an RNA molecule is formed that is what?
Signup and view all the answers
How many nucleotides are needed to specify three amino acids?
Signup and view all the answers
There are 64 codons and 20 amino acids. Which is true?
Signup and view all the answers
What happens during translation?
Signup and view all the answers
During translation, the type of amino acid that is added to the growing polypeptide depends on what?
Signup and view all the answers
A protein is being assembled when what occurs?
Signup and view all the answers
Genes contain instructions for assembling what?
Signup and view all the answers
What is the correct sequence of the transfer of information in most organisms?
Signup and view all the answers
What is a mutation that involves one or a few nucleotides called?
Signup and view all the answers
Give an example of a chromosomal mutation.
Signup and view all the answers
When a chromosome undergoes a deletion mutation, information is what?
Signup and view all the answers
Most mutations have no effect on an organism.
Signup and view all the answers
DNA is a nucleic acid made up of nucleosomes joined into long strands or chains by covalent bonds.
Signup and view all the answers
The nucleotides within a DNA strand may have different nitrogenous bases but all have identical sugar molecules.
Signup and view all the answers
Chargaff contributed to the understanding of DNA by figuring out that the percentages of adenine and thymine were almost equal in any sample of DNA.
Signup and view all the answers
Watson and Crick used the image of DNA taken by Franklin in their work to figure out the structure of DNA.
Signup and view all the answers
What are the three types of RNA?
Signup and view all the answers
During DNA replication, only one strand of DNA serves as a template.
Signup and view all the answers
How many nucleotides does a codon consist of?
Signup and view all the answers
The anticodon AGA is complementary to the mRNA codon TCT.
Signup and view all the answers
Study Notes
DNA and its Function
- DNA stores genetic information in cells, essential for heredity and biological functions.
- Functions like a book by storing, copying, and passing on information through generations.
Nucleotides and Base Pairing
- A nucleotide in DNA consists of deoxyribose sugar, a phosphate group, and a nitrogenous base (e.g., cytosine).
- Purines (adenine and guanine) are present in equal amounts to pyrimidines (cytosine and thymine) due to base pairing rules.
Key Discoveries in DNA Structure
- Rosalind Franklin utilized X-ray diffraction to produce images that helped inform the structure of DNA.
- James Watson and Francis Crick identified the DNA structure as a double helix.
- Discovery sequence: Chargaff's nucleotide ratios → Franklin's X-ray photos → Watson and Crick's double helix model.
DNA Replication
- Results in two DNA molecules, each containing one original and one newly synthesized strand.
- Occurs before cell division in both prokaryotic and eukaryotic cells.
- Example: A DNA strand with bases CTAGGT produces a complementary strand GATCCA.
RNA Basics
- RNA differs from DNA, containing ribose sugar instead of deoxyribose.
- Types of RNA: Messenger RNA (mRNA), Transfer RNA (tRNA), and Ribosomal RNA (rRNA) play roles in protein synthesis.
- mRNA carries genetic information from DNA to the rest of the cell.
Transcription and Translation
- Transcription produces RNA molecules that are complementary to DNA strands.
- During translation, the mRNA code is used to synthesize proteins, guided by codons linked to specific amino acids determined by tRNA anticodons.
Genetic Code
- 9 nucleotides are required to specify three amino acids, highlighting the relationship between codons and amino acids.
- There are 64 possible codons but only 20 amino acids, meaning multiple codons can correspond to a single amino acid.
Mutations
- A point mutation is a change involving a single nucleotide.
- Chromosomal mutations include deletions (loss of information) and inversions (reordering of segments).
- Most mutations have no noticeable effects on organisms' functioning.
Miscellaneous
- The three types of RNA have distinct roles in protein synthesis and genetic expression.
- Codons are groups of three nucleotides, fundamental to the genetic coding system.
- The anticodon of tRNA must match the codon of mRNA for correct protein assembly, noting that RNA uses uracil instead of thymine.
Studying That Suits You
Use AI to generate personalized quizzes and flashcards to suit your learning preferences.
Description
Test your knowledge of key concepts in Biology Chapter 12 with these flashcards. This quiz covers essential topics such as DNA structure, its functions, and the importance of nucleotide pairing. Strengthen your understanding and prepare for assessments with targeted questions.
