B16 - Inheritance Flashcards
What are chromosomes made of?
Chromosomes are made of DNA
DNA contains genetic information in the form of genes.
Define a gene.
A gene is a length of DNA that codes for a protein.
What is an allele?
An allele is an alternative form of a gene.
How is sex inherited in humans?
Sex is inherited in humans with reference to XX and XY chromosomes.
Describe a haploid nucleus.
A haploid nucleus contains a single set of chromosomes.
Describe a diploid nucleus.
A diploid nucleus contains two sets of chromosomes.
What is the chromosome PAIR count in a human diploid cell?
In a human diploid cell, there are 23 pairs of chromosomes.
Define mitosis.
Mitosis is nuclear division making two genetically identical cells.
What is the role of mitosis? (4)
The role of mitosis includes:
* Growth
* Repair of damaged tissues
* Replacement of cells
* Asexual reproduction.
What happens before mitosis?
The exact replication of chromosomes occurs before mitosis.
What happens during mitosis regarding chromosomes?
During mitosis, the copies of chromosomes separate, maintaining the chromosome number in each daughter cell.
What does meiosis produce?
Meiosis is the production of gametes.
Describe meiosis.
Meiosis is reduction division in which the chromosome number is halved from diploid to haploid, resulting in genetically different cells.
2n=
46 chromosomes
N=
23 chromosomes
What are the 23rd pair of chromosomes called?
Sex chromosomes
What chromosomes determine the gender of an individual?
XY = males
XX = females
Gender ratio
50:50
What is DNA replication
Chromosomes in the nucleus being copied (chromatids)
Where does meiosis occur?
In the testes or ovaries
How many daughter cells does Meiosis and mitosis create?
Meiosis: 4
Mitosis: 2
