Inheritance Flashcards
What occurs in the G1 phase?
Cell content replication
List the 4 stages of the cell cycle
G1, S, G2, M
What occurs during the S phase?
DNA replication
What occurs in the G2 phase?
Double checking and repair
What are the main stages of DNA replication?
Initiation, elongation, termination
Which enzyme joins together Okazaki fragments?
DNA ligase
List the 6 phases of mitosis
Prophase, prometaphase, metaphase, anaphase, telophase, cytokinesis
What happens in prophase?
Spindle fibres appear
Chromosomes condense
What happens in prometaphase?
Spindle fibres attach to chromosomes
What happens in metaphase?
Chromosomes align at the metaphase plate
What happens during anaphase?
Centromeres separate
Sister chromatids move to separate poles
What happens in telophase?
Nuclear membrane reforms
Chromosomes decondense
Spindle fibres disappear
What happens in cytokinesis?
Cytoplasm divides to form two daughter cells
What are two genes on the same chromosome said to be?
Linked
Define genotype
The genetic make-up of an individual
Define phenotype
The observable characteristics of an individual. The expressed traits of a specific genetic locus
List environmental factors that can have an effect on genotype and phenotype
Radiation Diet Mutagens Chemicals that can affect cell growth Lifestyle
What is a gene?
A unit of hereditary. A length of DNA on a chromosome that contains the code for a protein.
What is an allele?
An alternative form of a gene. Each individual has two alleles for the same gene, which can either be the same or different.
Give an example of co-dominant alleles
Blood type AB
What is complementation?
When more than one gene is responsible for the phenotype. Therefore a child of two recessive parents can be unaffected if parents have different defective genes and inherits healthy genes. Eg albinism
In a pedigree diagram, how would you draw an affected male?
Shaded in square
In a pedigree diagram, how would you draw a carrier female?
A circle either half shaded in or with a dot in the centre
