Which mutation causes either the inclusion of an extra chromosome in offspring or the deletion of an entire chromosome?
a) deletion
b) insertion
c) crossing-over
d) non-disjunction

D)non-disjunction

Explanation:

Our cells have 46 chromosomes (23 pairs). When a cell divides (mitosis or meiosis) and there is no separation of homologous chromosomes (equal to each other or forming a pair) a disjunction creates a cell or gamete (eggs and sperm) with more or less genetic material. A classic example of non-disjunction is the selection of chromosomes 21 in meiosis, producing fertilized gametes resulting in Down Syndrome or free chromosome 21 trisomy.

the growth of the plants is affected by the heat of the light. what is the student doing?