B16 - Inheritance Flashcards
What are chromosomes made of, and what do they contain?
Chromosomes are made of DNA, which contains genetic information in the form of genes
Gene definition
A (short) length of DNA that codes for a protein
Allele definition
An alternative form of a gene
How is sex inherited in humans with reference to XX and XY chromosomes?
In humans, females have two X chromosomes (XX), and males have one X and one Y chromosome (XY). The inheritance of sex is determined by the X or Y chromosome contributed by the father
What is a haploid nucleus?
A nucleus which contains a single set of chromosomes.
What is a diploid nucleus
A nucleus containing two sets of chromosomes
What is the chromosome structure in a diploid cell, and how many pairs are there in a human diploid cell?
In a diploid cell there is a pair of each type of chromosome
In a human diploid cell there are 23 pairs
Mitosis definition
Nuclear division giving rise to (resulting in) genetically identical cells
What is the role of mitosis?
Mitosis is responsible for growth, repair of damaged tissues, replacement of cells, and asexual reproduction
When does the exact replication of chromosomes occur in relation to mitosis?
The exact replication of chromosomes occurs before mitosis
What happens to the copies of chromosomes during mitosis?
During mitosis, the copies of chromosomes separate, maintaining the chromosome number in each daughter cell
What is the role of meiosis?
Meiosis is involved in the production of gametes
Meiosis definition
Reduction division in which the chromosome number is halved from diploid to haploid resulting in genetically different cells
