Help me, please
ONLY ANSWER IF YOUR PLAN ON DOING ALL 4 QUESTIONS

Explanation:

1. Organism-ecosystem

2. Ecosystem

3.A

4. oxygen we inhale

sorry it took a bit-

Explanation:

1) b because a book is in a library as a organism is in a ecosystem - they both flow

2) a, ecosystem because the description describes living and nonliving things together, which makes it a ecosystem since a community is just the living things. Also population doesnt make sense because aain its nonliving and living things and has no numbers or anything to indicate a population. Also cant be organism since its several things not just one living thing.

3) C, because it says aibiotic, which is nonliving, making a, b and d wrong.

4)a, because the food we eat is biotic, the rest aren't

fertilization, pictured in figure 24.23a is the process in which gametes (an egg and sperm) fuse to form a zygote. the egg and sperm each contain one set of chromosomes. to ensure that the offspring has only one complete diploid set of chromosomes, only one sperm must fuse with one egg. in mammals, the egg is protected by a layer of extracellular matrix consisting mainly of glycoproteins called the zona pellucida. when a sperm binds to the zona pellucida, a series of biochemical events, called the acrosomal reactions, take place. in placental mammals, the acrosome contains digestive enzymes that initiate the degradation of the glycoprotein matrix protecting the egg and allowing the sperm plasma membrane to fuse with the egg plasma membrane, as illustrated in figure 24.23b. the fusion of these two membranes creates an opening through which the sperm nucleus is transferred into the ovum. the nuclear membranes of the egg and sperm break down and the two haploid genomes condense to form a diploid genome.

explanation: