10.3 Chromosomes Flashcards
Why is DNA wrapped and packaged?
To protect it from damage since it is very long and fragile.
What are chromosomes and where are they located?
Chromosomes are bundles of tightly coiled DNA located in the nucleus of most living cells.
How is a chromosome formed?
- DNA is wrapped around proteins called histones
- It is then further coiled and wrapped to form a chromosome
When is the only time that DNA forms visible (XX) chromosomes in cells?
When the DNA condenses during cell division
Name the 4 types of eukaryotic chromosomes:
- Telocentric
- Acrocentric
- Submetacentric
- Metacentric
What is the place where genes are located known as?
A locus
What are the sections between genes called?
Spaces, intragenic regions, or junk DNA
What is the ploidy level?
The number of chromosomes in a celll.
What are organisms with more than 2 sets of chromosomes classed as?
Polyploid
What are gametes classed as?
Haploid (N)
How many copies of chromosomes do somatic cells have?
2, because they are diploid (2N)
What are autosomes?
- All the chromosomes other than sex chromosomes
- Do not determine gender
What are sex chromosomes?
- All the chromosomes other than autosomes
- Determine gender
What is the purpose of karyotyping?
To look at the total number of chromosomes in a cell, and to identify any abnormalities.
What is a karyotype?
An image or picture of all the chromosomes in a cell
