Chromosomes, Genes & DNA Flashcards
Which cells do not have pairs of chromosomes?
Sex cells-gametes HAPLOID (23 chromosomes)
Do bacterial cells contain chromosomes?
No!
What are genes?
Short lengths of DNA which code for a particular characteristic.
What is the genome?
All the DNA in an individual.
What are chromosomes?
Genetic structures occurring in functional pairs in the nucleus of cells, EXCEPT GAMETES and BACTERIA!
DNA consists of three sub-units that are repeated regularly along the length of a molecule, what are their names?
A deoxyribose sugar, bases and phosphate.
What are the name of the four bases?
Adenine, Guanine, Cytosine and Thymine (ALL CAN BE ABBREVIATED!)
What term is used to describe the three-dimensional shape of a DNA molecule?
Double helix.
Each repeating unit of DNA, consisting of a base, a deoxyribose sugar and phosphate is called a what?
A nucleotide.
What base always links together with Adenine?
Thymine (or vice verse)
What base always links together with cytosine?
Guanine (or vice verse).
How does the DNA of individuals differ?
No two individuals will have the same sequence of bases along the length of the DNA molecule. Their DNA will be unique to them (the only exception to this are identical twins).
The bases along one side of the DNA molecule (the forming strand) form what?
The genetic code.
How many bases need to be in one sequence?
Three (a triplet).
The sequence of bases that codes for an amino acid is called a what?
A base triplet.
How do you know if two amino acids will be the same?
If they have the same sequence of bases.
How do sperm cells differ from germ cells with respect to the sex chromosomes?
Each sperm cell has ONE sex chromosome (x OR y). Germ cells have TWO sex chromosomes (x AND y).
