DNA & RNA (chpt. 15) Flashcards
Classification
Placing organisms into similar groups
Taxonomy
The study of classification
Species
A species is a group of organisms capable of interbreeding naturally to produce fertile offspring
Variation
Members of a species show different characteristics
Heredity
Is the passing on of features from parents to offspring by means of genes
Gene expression
The way in which genetic information in a gene is decoded in the cell and used to make a protein
Chromosomes
Thread like structures made up of DNA and protein, found in the nucleus of the cell
What are chromosomes made up of
DNA + protein
The DNA is wrapped around proteins which are called histones
What are genes made up of
DNA
Exons
Coding structures of genes
Junk DNA
Non coding lengths of DNA
Introns
Non coding lengths of DNA
What does DNA stand for
Deoxyribonucleic acid
4 nitrogenous bases
Guanine G
Cytosine C
Adenine A
Thymine T
What does guanine pair with
Cytosine
What does cytosine pair with
Guanine
What does adenine pair with
Thymine
What does thymine pair with
Adenine
What makes up a nucleotide
Phosphate group
Sugar group (deoxyribose sugar)
One of four nitrogenous bases (guanine, cytosine, adenine, thymine)
Genetic code
A sequence of bases in DNA that provide instructions for a cell to form a protein
Codon / triplet
DNA codes for each amino acid by a sequence of 3 consecutive bases
Pyrimidine bases
Thymine
Cytosine
Purine bases
Adenine
Guanine
Who discovered the structure of DNA
Watson & crick
What did Watson and crick discover
The structure of DNA
Protein synthesis - initiation
The DNA double helix unwinds at the site of the gene that is going to produce a protein
Enzymes break the bonds between the bases
Takes place in nucleus
RNA
Ribonucleic acid
DNA vs RNA
Double helix Vs Single strand
Deoxyribose sugar Vs Ribose sugar
Thymine base Vs Uracil base
Nucleus Vs Nucleus and cytoplasm
Long Vs Short
Self replicating Vs Replicated from DNA
How is RNA different from DNA
Base uracil instead of thymine
Ribose sugar instead of deoxyribose
Has a single strand not a double strand
What is DNA profiling
The unique pattern of a persons DNA
Steps in DNA profiling
- Cell wall/membrane is broken down to release DNA
- DNA is cut into fragments by restriction enzymes
- DNA fragments are separated by gel electrophoresis
- Unique DNA profiles are compared
Uses of DNA profiling
Medical
Forensics
Genetic screening
Testing DNA for the presence or absence of a particular gene or an altered gene
Steps in transcription
DNA -> RNA
In nucleus
1. RNA bases move across the cytoplasm
2. The exposed DNA bases match with RNA bases to form mRNA
3. The enzyme RNA polymerase connects the bases together to form mRNA
How many of each codons do genes have
One start
Many specifying amino acids
One stop
Ribosome
A special decoding device made of small and large subunits, ensuring that amino acids are assembled in the correct sequence according to the mRNA
Types of RNA
mRNA - messenger RNA
tRNA - transfer RNA
rRNA - ribosomal RNA
