3.11 - Chromosomes Flashcards
What chromosomes and chromatids are What homologous chromosomes are The structure of chromosomes after replication The terms haploid and diploid
Where are chromosomes located?
Inside the nucleus of animal and plant cells
What do chromosomes consist of?
DNA tightly coiled around histones
How many chromosomes do humans have in total?
46
How many pairs of chromosomes do humans have?
23
What are the first 22 pairs of chromosomes called?
Autosomes
What is the 23rd pair of chromosomes called?
Sex chromosomes
What sex chromosomes do males have?
XY
What sex chromosomes do females have?
XX
What do each pair of chromosomes consist of?
Two homologous chromosomes
What are homologous chromosomes?
Pairs of chromosomes with one paternal and one maternal chromosome
What is the difference between homologous chromosomes?
They may contain different alleles
How many chromatids can chromosomes contain?
One or two
When does DNA replication occur?
During interphase
What holds sister chromatids together?
Centromere
What are sister chromatids?
Genetically identical chromatids
What type of cells are body cells in most organisms?
Diploid
What type of cells are sex cells (gametes) in most organisms?
Haploid
What do diploid cells contain?
Two copies of each chromosome
What is the total number of chromosomes in diploid cells represented by?
2n
How many chromosomes do human body cells have?
46
What do haploid cells contain?
One copy of each chromosome
What is the total number of chromosomes in haploid cells represented by?
n
How many chromosomes do human sex cells have?
23
