What chromosomes are homologous pairs?
Homologous chromosomes are made up of chromosome pairs of approximately the same length, centromere position, and staining pattern, for genes with the same corresponding loci. One homologous chromosome is inherited from the organism’s mother; the other is inherited from the organism’s father.
Is the 23rd pair of chromosomes homologous?
The collection of all 23 human chromosome pairs (called a karyotype) is shown below for an adult male; the 23rd pair are the X and Y sex chromosomes, which are not homologous; in contrast, two female X chromosomes are usually considered homologous.
What is a homologous chromosome in biology?
1. A pair of chromosomes made up of two homologs. Homologous chromosomes have corresponding DNA sequences and come from separate parents; one homolog comes from the mother and the other comes from the father. Homologous chromosomes line up and synapse during meiosis.
What are the 4 stages of the cell cycle?
In eukaryotes, the cell cycle consists of four discrete phases: G1, S, G2, and M. The S or synthesis phase is when DNA replication occurs, and the M or mitosis phase is when the cell actually divides. The other two phases — G1 and G2, the so-called gap phases — are less dramatic but equally important.
Are all chromosomes fully homologous?
All body cells contain pairs of homologous chromosomes. … The exception to the diploid number are eggs and sperm cells.
Is zygote homologous chromosome pair?
When an egg and sperm are united during fertilization, the resulting zygote has 23 pairs of homologous chromosomes, one in each pair from the egg and one from the sperm.
What are homologous pairs in meiosis?
Somatic cells are sometimes referred to as “body” cells. Homologous chromosomes are matched pairs containing the same genes in identical locations along their length. Diploid organisms inherit one copy of each homologous chromosome from each parent; all together, they are considered a full set of chromosomes.