Genetics Flashcards
Each human has how many pairs of chromosomes?
23 pairs in total
22 autosomal pairs, 1 sex-linked pair
G0 phase of the cell cycle
Most cells are resting, carrying out their normal function
G1 phase of the cell cycle
1st growth phase as chromosomes become ready to be replicated
S phase of the cell cycle
DNA replication occurs
G2 phase of the cell cycle
2nd growth phase involving proteins etc.
M phase of the cell cycle
Mitosis - mechanical separation of cell into two daughter cells
Two daughter cells are identical, diploid cells
Variation occurs during meiosis by two main methods, which are?
Crossing over
Independent segregation of homologous chromosomes
In meiosis, one diploid cell becomes…
Four haploid daughter cells
Examples of sequence variations between genes?
Single nucleotide polymorphisms (SNPs)
Deletions/duplications
A polymorphism is…
A change in the genome that does not cause disease in its own right, but can predispose to a common disease
Chromosome 22 looks like a…
Teddy bear
A chromosome consists of…
Telomeres at each end
Short arm (p)
Centromere
Long arm (q)
A chromosome is metacentric if…
Both arms are roughly the same length
A chromosome is acrocentric if…
The p (short) arm is so short it is hard to observe
A chromosome is telocentric if…
The centromere is located at the terminal end of the chromosome