The diagram shows the results of meiosis. The parent cell has one pair of chromosomes. The locations of three genes are shown
on each chromosome.
Parent Cell
Sex Cells
(
Why are the chromosomes in two of the sex cells different from the chromosomes in the parent cell?
some of the genes were damaged during replication
an insertion mutation occurred during replication
crossing over occurred in the chromosome
the chromosomes from another parent cell were introduced

which

what is a measurement of the earth’s history divided into time periods?

> fossil record <

sedimentary rock

> geologic time scale <

radioactive elements

d. planting trees

the trees take in carbon to make oxygen.

in a chemical reaction, the atoms and molecules produced by the reaction are called products. no new atoms are created, and no atoms are destroyed. in a chemical reaction, reactants contact each other, bonds between atoms in the reactants are broken, and atoms rearrange and form new bonds to make the products.