Answer:
50
Explanation:
egg cells and sperm cells contain half of the chromosomes of a regular cell in an organism, so the number of chromosomes in a heart cell must be double of the chromosomes in a egg cell.
D. living things as a reservoir
Answer:
The highest level of organization for living things is the biosphere; it encompasses all other levels. The biological levels of organization of living things arranged from the simplest to most complex are: organelle, cells, tissues, organs, organ systems, organisms, populations, communities, ecosystem, and biosphere.
Explanation: