Unit A Biological Diversity: Section 3.0 Flashcards
What are the blueprints for an organism?
DNA
What does DNA stand for?
Deoxyribonucleic acid
What is DNA found in?
The nucleus of a cell
What did Watson and Frick find?
By unraveling the structure of DNA, Watson and Crick revealed how the same chemical building blocks could carry such a wide range of instructions needed for the diversity we observe in the living world.
What does a DNA molecule look like?
A ladder twisted into a spiral
What are the four different chemicals in the DNA?
Thymine
Adenine
Guanine
Cytosine
What is the genetic code?
The way that the chemicals in DNA are arranged. GC and AT are pairs
What are chromosomes?
The way that DNA arranges itself in a cell.
How many chromosomes does each human cell contain?
46 chromosomes, or 23 chromosome pairs
In what way do chromosomes organize themselves?
In pairs
What is a gene?
An uninterrupted segment of
DNA, which contains coded instructions
Where are genes located?
Genes are located on the chromosomes
Where are genes located?
Each chromosome contains numerous gene locations.
How are genes found?
In pairs, both genes in a pair carry DNA instructions for
the same thing. The genes occupy
matching locations on the two chromosomes.
What are alleles?
The possible forms that genes come in. E.g. Red Hair, Blue Hair etc
What is mitosis responsible for?
Mitosis occurs in the body cells of multicellular organisms and is responsible for the growth and cellular repair of a multicellular organism.
What is meiosis?
Meiosis is a type of cell division that produces cells with only half the DNA of a normal cell. Because each gamete has only half the DNA of a normal cell, when the male and female gametes unite, the zygote has a complete set of DNA
What is mitosis to do with?
Binary fission, and growth and cellular repair in a multicellular organism
What is the difference between meiosis and mitosis?
Meiosis is two cell divisions that only produces half the DNA of a cell. Mitosis is one cell division that produces cells with identical information
Explain how mitosis works?
1: The chromosomes duplicate
2: Then the nucleus disintegrates
3: The cell is split in half taking half the chromosomes and now there are 2 cells
Explain hoe meiosis works?
1: the chromosomes duplicate
2: they swap information
3: and then the cell splits in half and then split in half again making 4 cells with half the information
What are traits?
Characteristics
What are purebred organisms?
An organism which has ancestors with all the same traits
What are hybrid organisms?
Organisms with ancestors with different traits
What are dominant traits?
Traits that will take over when presented against a recessive traits
What is a recessive trait?
A trait that does not dominate
What is incomplete dominance?
When neither trait is completley dominant
What is the inherited material responsible for variation?
DNA
What did Oswald Avery discover?
DNA
