Genetics Flashcards
What does DNA stand for?
Deoxyribonucleic acid
Where is DNA found?
In the nucleus of cells
What is DNA composed of?
DNA is composed of billions of nucleotides.
-A double strand of nucleotides linked together by a phosphate and sugar molecules and ultimately fporms a double helix shape.
Genetics: Chromosome
A condensed form of DNA
-Humans have 46 chromosomes (23 from mother and 23 from father)
What does DNA do?
DNA codes or provides instructions for the cell to produce proteins.
DNA is composed of 4 types of Nucleotides
1) Adenine (pairs with Thymine)
2) Guanine (Pairs with Cytosine)
3) Thymine
4) Cytosine
What is the strand part (Backbone) of DNA composed of
Phosphate and sugar molecules.
DNA: Gene
The specific sequence of nucleotides
DNA mutation
Change in a particular gene’s nucleotide sequence.
DNA Replication: When is DNA replicated?
During the synthesis phase of interphase of the cell cycle
Protein Synthesis: What does genome refer to?
Refers to all of the DNA within an organism.
What two main processes occur for the creation of protein?
1) Transcription
2) Translation
Protein Synthesis: Transcription
-Occurs in the Nucleus
Creates a copy of the gene - called mRNA
Protein Synthesis: Translation
Occurs in the cytoplasm
-mRNA strand is “read” by ribosomes which creates protein (a specific sequence of amino acids bonded together determined by the sequence of nucleotides within the gene.)
Cell Cycle and Cell Reproduction: Why must cells reproduce
Cells must synthesize proteins to be able to perform ints functions and divide into two new cells to replace worn out, injured or dead cells.
Which cells cannot reproduce?
Myocytes (Heart muscle cells) and Neurons (Nerve cells)
Cell Cycle: What is it?
The cell cycle represents the events that occur int he cell from when it forms to when it completes a cellular division
-Different cells have different cell cycle rates
Cell Cycle: What is the broad categories?
- Interphase
- Mitosis
Cell Cycle: Mitosis
The category of the cell cycle where the cell prepares to divide into two new cells.
Cell Cycle: Mitosis Phases
1) Prophase
2) Metaphase
3) Anaphase
4) Telophase
What is cytokinesis?
When a cell actually divides into two new cells.
Mitosis - Prophase
- Chromatin begins to coil and condense to form chromosomes
- Each duplicated chromosome consists of two strands and each strand contains a single molecule of DNA
- The two chromatids join together in the middle at a spot called the centromere
- Centrioles move to opposite poles of the cell, and spindle fibers appear
- The nuclear envelope dissolves and spindle fibers form in the cytoplasm
Mitosis: Metaphase
- Some of the spindle fibers attach to one side of the chromosomes at the centromere
- The chromosomes line up along the center of the cell
Mitosis: Anaphase
- The centromeres divide, forming two chromosomes instead of a pair of attached chromatids
- The spindle fibers pull the newly formed chromosomes to opposite poles of the cell.
Mitosis: Telophase
- A new nuclear envelope develops around each set of daughter chromosomes
- The spindle fibers disappear, and the cytoplasm divides to produce two identical daughter cells.
Mitosis vs. Meiosis
Sperm cells and egg cells go through meiosis process
Mitosis: Cells end up with full genome
Meiosis: Cells end up with half genome
What is interphase?
The time between mitotic phases (G1, S and G2)
What is G1?
First gap phase: Synthesis of components needed for DNA
What is S?
Synthesis phase: DNA replication
What is G2?
Second gap phase: Preparation for mitosis
