CELL STRUCTURES AND FUNCTION
CELL DIVISION
|
Question
[CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
|
|
|
genes
|
|
|
chromosomes
|
|
|
genomes
|
|
|
phenotype
|
Detailed explanation-1: -A single chromosome can have hundreds or even thousands of genes. Most sexually reproducing organisms, like people and pigeons, have two copies of each chromosome, called homologous chromosomes. Humans have 23 chromosome pairs, or 46 chromosomes in all.
Detailed explanation-2: -Chromosomes are also different sizes. The human X chromosome is about three times larger than the human Y chromosome, containing about 900 genes, while the Y chromosome has about 55 genes. The unique structure of chromosomes keeps DNA tightly wound around spool-like proteins, called histones.
Detailed explanation-3: -One chromosome is made of two chromatids and each chromatid is a DNA molecule. Each DNA molecule is a double helix. So two DNA molecules per chromosome.
Detailed explanation-4: -Genes are made up of DNA. Each chromosome contains many genes.