The greatest amount of day-to-day variation is produced by the process of

Question

a. mitosis.

b. meiosis.

c. crossing-over.

d. mutations and the regular cell cycle.

e. meiosis and crossing-over.

Answer 1

all i kw is crossing over produces variations..

hope dats rite..

Answer 2

E. Meiosis and crossing over

During meiosis, the genome of a diploid germ cell, which is composed of long segments of DNA packaged into chromosomes, undergoes DNA replication followed by two rounds of division, resulting in four haploid cells. Each of these cells contain one complete set of chromosomes, or half of the genetic content of the original cell.

Chromosomal crossover (or crossing over) is the process by which two chromosomes pair up and exchange sections of their DNA. This often occurs during prophase 1 of meiosis in a process called synapsis. Synapsis begins before the synaptonemal complex develops, and is not completed until near the end of prophase 1. Crossover usually occurs when matching regions on matching chromosomes break and then reconnect to the other chromosome. The result of this process is an exchange of genes, called genetic recombination.  

Answer 3

During Meiosis Crossing over of adjacent chromatids occurs during Prophase I random assortment of homologous pairs occurs during Metaphase I. Both of these lead to varistion in the gametes formed for sexual reproduction.

BUT

On a day to day basis random mutations occur in somatic cells and these are replicated during mitosis for growth and repair.