1. What is a species? A group of organisms so similar to one another that they can breed and produce fertile offspring.

2. In plants, the pollen must be able to “match perfectly” shape-wise to the stigma of the female part of the flower. If the match occurs, then the pollen digests a tube to the eggs below. Fertilization can take place. Pansy pollen doesn’t match yucca stigmas. Sunflower pollen doesn’t match rose stigmas.

3. In animals, the tip of the sperm must match (shape-wise) to the egg’s covering. One protein on the tip of the sperm One protein on the covering of the egg.

4. If the shape of the proteins don’t match, then no baby is made. red protein If the sperm (red protein) from a sea turtle is brown put on the egg (brown protein protein) of a snapping turtle, fertilization doesn’t take place. Snapping turtles are a different species than sea turtles.

5. Sometimes the proteins of two species gametes are very close in shape and size. Cow protein on egg Buffalo protein on egg 30 chromosomes Male bull 30 chromosomes Female buffalo 30 chromosomes Beefalo fertility, milking ability, and ease of handling hardiness, foraging ability, calving ease, and meat quality

6. The egg’s protein of a horse matches the sperm’s protein of a donkey. Mule

7. Donkeys have 62 chromosomes Horses have 64 chromosomes Mules have 63 chromosomes that are a mixture of one from each parent. The chromosomes don’t pair up properly during meiosis, so sex cells are rarely made in mules. Though very uncommon, some fertile mules do exist. Mule

8. Are Ligers a species? Only if they can breed to produce fertile offspring.

9. Dogs, wolves and foxes are similar. Can they mate and produce fertile offspring?

10. Breeds of dogs can interbreed. Dogs are one species. Sometimes, dogs and wolves interbreed though they are not the same species.

11. How dogs in cold places may have all end up with long hair. Die from being cold.