yearly: Adjective for something that happens every year. (in botany) A plant that only lives one year, therefore usually has a showy flower and produces many seeds.

Arctic: A region that falls within the Arctic Circle. The edge of this circle is defined as the northernmost point where the sun can be seen on the northern winter solstice and the southernmost point where the midnight sun can be seen on the northern summer solstice. The high Arctic is the northernmost third of this region. It is a region that is dominated by snow cover for most of the year.

calorie: The amount of energy needed to raise the temperature of 1 gram of water by 1 degree Celsius. It is typically used as a measure of the energy contained in a given amount of food. The exception: when referring to the energy in food, one kilocalorie or 1,000 of those calories is referred to as a “calorie”. Here, a food calorie is the amount of energy needed to increase 1 kilogram of water by 1 degree C.

canine: Members of the biological family of canids. These are carnivores and omnivores. The family includes dogs, wolves, foxes, jackals, and coyotes.

carbohydrates: A large group of compounds found in food and living tissues, including sugar, starch, and cellulose. They contain hydrogen and oxygen in the same ratio as water (2: 1) and can typically be broken down in an animal’s body to release energy.

colleague: Someone who works with someone else; an employee or a team member.

diet: (n.) The foods and liquids that are ingested by an animal to provide the nourishment it needs to grow and maintain good health. (v.) Adopt a specific feeding schedule. For religious or ethical reasons, people may follow a certain diet to fight food allergies, control their body weight, or control a disease like high blood pressure or diabetes.

docile: An adjective that means calm, cooperative, submissive, or deferential.

Domestication: A process of making a tame version of an animal from a wild animal that can take thousands of years to complete. One domesticated animal was bred in captivity.

edible: Something that is safe to eat.

Eurasia: The part of the world that is covered by Europe and Asia.

fat: A natural oily or greasy substance found in plants and animal bodies, especially when deposited as a layer under the skin or around certain organs. The main job of fat is the energy reserve. Fat is also a vital nutrient, although it can be harmful if consumed in excessive amounts.

generation: A group of individuals (in any species) who were born at about the same time or are considered a single group. For example, your parents are from one generation of your family and your grandparents are from another. Similarly, you and everyone around the world within a few years of your age will be referred to as belonging to a specific generation of people. The term is sometimes extended to include annual classes of other animals or types of inanimate objects (such as electronics or automobiles).

Hunters and collectors: A cultural group that feeds on hunting, fishing and collecting wild products (such as nuts, seeds, fruits, leaves, roots and other edible parts of plants). They can be a little nomadic and don’t rely on agriculture for their food.

Ice age: Earth has experienced at least five major ice ages, which are extended periods of unusually cold weather experienced by much of the planet. During this time, which can last hundreds to thousands of years, glaciers and ice sheets expand in size and depth. The most recent ice age peaked 21,500 years ago, but lasted until about 13,000 years ago.

diary: (in science) A publication where scientists share their research with experts (and sometimes even the public). Some magazines publish articles from all areas of science, technology, engineering, and math, while others focus on a single subject. The best journals are reviewed by experts: They send all submitted articles to external experts to read and criticize. The goal here is to prevent posting of bugs, scams, or sloppy work.

liver: An organ of the animal body with a backbone that fulfills a number of important functions. It can store fat and sugar for energy, break down harmful substances for elimination by the body, and secrete bile, a greenish liquid that is released into the intestines, where it helps digest fats and neutralize acids.

mark: (in Physiology and Medicine) Spongy tissue that develops within the bones. Most red blood cells, infection-fighting white blood cells, and platelets are made in the marrow.

prey: (n.) Species that are eaten by others. (v.) Attack and eat another species.

protein: A compound of one or more long chains of amino acids. Proteins are an essential part of all living organisms. They form the basis of living cells, muscles and tissues; They also do the work inside cells. The more well-known independent proteins include hemoglobin (in the blood) and the antibodies (also in the blood) that try to fight infections. Drugs often work by attaching to proteins.

Puppy: A term given to the young of many animals, from dogs and mice to seals.

scenario: A possible (or probable) sequence of events and how they might play out.