Topic 3 - Genetics Flashcards
DNA
A molecule in the shape of a double helix that contains your genetic code. (T,A,G,C)
Double Helix
Two strands of DNA joined and twisted together, like a spiral staircase.
Nucleotide Base (in
DNA)
Four bases help make up DNA, often shown by the letters A, C, G and T.
Sugar– phosphate
backbone
Main strand of DNA where nucleotide bases attach. It is made of sugar and phosphate
Adenine (A)
One of four bases found in DNA. Often written as A.
Thymine (T)
One of four bases found in DNA. Often written as T.
Guanine (G)
One of four bases found in DNA. Often written as G.
Cytosine (C)
One of four bases found in DNA. Often written as C.
Hydrogen Bonds
The bonds that connect base pairs together
Complementary base pair
Two DNA bases that link by hydrogen bonds.
(A-T) (C-G)
Chromosome
A structure found in the nuclei of cells. Each chromosome contains one enormously long DNA molecule surrounded by proteins.
Gene
Secton of the long strand of DNA, which contains instructions to code for a protein.
Genome
All the genes found in one cell of an organism.
Replicate
When DNA replicates it makes a copy of itself.
Daughter Cell
The cells produced by a cell when it divides
Diploid
A cell or nucleus that has two sets of chromosomes. In humans, almost all cells except the sperm and egg cells are diploid (46).
Haploid
A cell or nucleus that has one set of chromosomes. Gametes are haploid. (23)
Meiosis
A form of cell division in which one parent cell produces four haploid daughter cells.
Asexual reproduction
Producing a clone of the parent by mitotic cell division.
Gamete
A haploid cell used for sexual reproduction. (Sperm from males, egg from females)
Fertlisiation
Fusing of a male gamete (sperm) with a female gamete (egg).
Zygote
Fertilized egg cell ‐ When sperm and egg fuse together this is a zygote.
