PBL

1. PBL 9N

2. DRIVING QUESTION! What is biological diversity, and by what processes do diverse living things pass on their characteristics to future generations?

3. What does biodiversity mean? • Biodiversity means different kinds of species and ecosystems on earth and the ecological processes they are part of.

4. Explain the 5 components of biodiversity? • Ecosystem Diversity – there are many different types of ecosystems, such as marshes, lakes, streams and forests • Community Diversity – populations of different species living within a community • Species Diversity – there are many variations within a particular species

5. 5 Components of Biodiversity Cont’d • Genetic Diversity – there is a variety of genetic material in all living things. • Species Distribution Diversity – plant and animal species are not evenly distributed throughout the various ecosystems on earth.

6. What area of the Earth do we find the most biodiversity? • We find the most biodiversity in the Tropical Rainforests and around the equator.

7. Why are coral reefs called “the Amazons of the oceans?” • Coral reefs are called the “amazons of the ocean” because, just like the amazon rainforest, coral reefs are extremely rich in species diversity.

8. What does interdependence mean? • Interdependence is when a species is dependent on other species in it’s environment • For example: humans depend on plants to get nutrients and oxygen to survive.

9. What is an important example of interdependence found in nature? • *Food chains and food webs. • *Symbiosis • *When animals depend on plants to survive.

10. What is symbiosis and also explain the three different types of symbiosis, making sure to explain examples for each? • Symbiosis is a type of interdependence. It is a relationship between two or more different species • Types of symbiosis: • # 1: Commensalism – when one organism benefits and the other doesn’t benefit or loses. Ex. bird living in a tree; the bird gets a home, and the tree is not effected.

11. Types of Symbiosis Cont’d • #2: Mutualism – when both organisms benefit. Ex. when humans give carbon dioxide to the plants while the plants gives oxygen to the humans • #3: Parasitism – when one organism benefits and the other is harmed. Ex. tape worm and human; the worm gets nutrients and food, while the human is harmed because his organs are damaged.

12. What is a niche? • A niche describes the role of an organism in the ecosystem: what it eats, habitat, nesting sites etc.

13. Why are niches important? • Niches allow organisms to exist in the same place. If one species in the ecosystem becomes extinct, all other organisms are affected.

14. Give an example of an ecosystem and name some animals that live in that ecosystem and the niches they would fill. • A Canadian Boreal forest is an example of an ecosystem. Some animals: • A honey bee pollinates the flowers. • The worms decompose decaying animal and leaves. • Foxes eat small rodents, insects and berries found in it’s habitat. • A raccoon’s niche is to eat and scavenge through the leftovers from larger carnivores.

15. Explain whether niches stay the same or can change...if they change explain this. • Niches have the ability to change during a species life which can be caused by environmental changes or perhaps the species it inter-relates with for survivability.

16. What are two ways a niche can change…give a couple of examples to explain the two ways niches can change? • A niche can change when there is too much or too less competition, or when the resources are more abundant or less abundant. For example: when a seagull leaves it natural habitat and transfers to a city-like area, it takes on the role of scavenging trash. • --OR-- • When a rodent overpopulates a habitat, then a predator takes the role of decreasing the population of the rodent.

17. What is resource partitioning and give an example to help explain this? • The process of species living in the same ecosystem dividing up resources so that each species develops different resource requirements to avoid competition. Ex: Two species of squirrels--one eats acorns from the branches; one eats acorns that have fallen.

18. What are two reasons that variability is important in an ecosystem? • Variability is important in an ecosystem because if there is an environmental change then it is more likely the species with the most variability will survive. • Also, variability means that the ecosystem is healthy and the species there are stronger.

19. Explain what natural selection is and how it relates to variability. • Natural selection is when nature chooses which organisms will survive to reproduce. It relates to variability because nature will choose the species with the highest survival rate and variation. The variation, or differences are what allow the species to survive, and that is how natural selection relates to variability.

20. Describe why variation is important in the environment? • Variation is important in the environment because it helps species adapt, and survive and adapt. • If all animals were the same, they would all be affected the same way. For example: If a virus were to spread, then all the animals would die because they would be exactly the same. • If there is variation in an environment, then it means that the environment is healthy.

21. Explain the difference between heritable and non-heritable traits and give some examples of each. • Heritable traits are passed on from generation to generation. Some examples are eye color, hair type, and skin color. • Non-heritable traits are acquired, and are not passed on to other generations. Some examples are the ability to play an instrument, or artificial change (such as dyeing hair, painting nails).

22. Explain how environment can play a role in the development of characteristics and give some examples of how environment can affect characteristics. • Environment plays a role in the development of characteristics because it can affect and influence in many ways. It can influence the organism itself. The organism may adapt to specific environmental requirements, either itself, or by natural selection of its descendants. Some examples: • The sun can darken a person’s skin, Nutrition and food can affect height, weight, and size.

23. Explain the difference between discrete and continuous variation and give some examples of each. • Discrete variation refers to differences in characteristics that have a defined form. For example, a person either has black hair or does not, or a lizard either has green eyes or does not. It is an “either/or” form of characteristic. • Continuous variation refers to differences in characteristics that have a range of forms. For example, the length of a person’s hair can range, or a person’s height can range from 1.2 m to 2.1 m.

24. Explain what asexual reproduction means and explain the four types of asexual reproduction with examples: • Asexual reproductions means that there is only one parent, and the offspring are identical to that parent because it makes a carbon copy of itself. The different types are: • #1. Binary Fission: a cell splits exactly in two, producing two identical individuals. For example: bacteria, amoebas and algae reproduce by binary fission.

25. Types of Asexual Reproduction Cont’d • #2. Budding: the parent produces a small bud, or a smaller version of itself; in animals, the bud eventually detaches. For example: yeast, and coral reproduce like this. • #3. Spore Production: spores are produced by the division of cells of the parent, and each spore develops into an individual. • #4. Vegetative Reproduction: the reproduction of a plant that doesn’t involve the formation of a seed. For example: if you take a part of a plant and place it separately, then the part grows roots and develops into an individual plant. Tubers and bulbs are also forms of vegetative reproduction.

26. Give a scientific explanation of sexual reproduction • Sexual reproduction is when two individuals combine genetic material and create a new organism. The two main processes are meiosis and fertilization. • Most species of animals and plants reproduce sexually, and the reproduction also occurs in species that do not any genders. • This kind of reproduction provides more variation, and forms a healthier environment.

27. What special cells are involved in sexual reproduction? • The special cells that are involved in sexual reproduction are called sperms and eggs, and are also known as gametes.

28. In animals, what are the specialized cells called that are involved in sexual reproduction and what do they produce when they combine? What is formed next? • Spermatozoa and ovum are involved in sexual reproduction and they produce zygote when combined. The zygote divides mitotically and differentiates into an embryo.

29. Briefly describe how sexual reproduction works in plants. • Haploid gametes are produced through meiosis; male cells are produced which are encapsulated in a pollen grain, female cells form ovules held within an ovary. Through the process of pollination, male pollen grains are transferred to the stigma of a receptive flower. The pollen grain germinates and a pollen tube grows down the style and into the ovary, where it releases the male gamete - this then fuses with the ovule forming a diploid zygote. Then after further mitosis develops into an embryo. The embryo is encapsulated within a testa and forms a seed as the ovary ripens to form the fruit.

30. Briefly explain the three types of sexual reproduction in plants. • a) Cross pollination occurs when pollen from one plant combines with the ovule of another plant. The resulting plants are not identical to either parent. • b) If plants self-pollinate, pollen from same plant unites with ovule of same plant, then the resulting plants are identical to the parents. • c) In artificial pollination, flowers are pollinated by man.

31. Give one major advantage and disadvantage of both sexual and asexual reproduction. • *Asexual reproduction: Advantage - Can produce many organisms very quickly which is an advantage in an environment that doesn’t change very much. • Disadvantage - All the individual organisms are the same and if the environment changes, all the organisms will die because there is not variation to allow some to adapt and survive • *Sexual reproduction: Advantage - Provides lots of variation helping it to survive when the environment changes. • Disadvantage - The process of sexual reproduction takes lots of energy, so populations tend to be smaller.

32. What are some examples of organisms that can reproduce both asexually and sexually? • Many plants, sponges and yeasts can produce both sexually and asexually. Aphids are non-plant species that can reproduce both ways.

33. The Answer to the Driving Question: Biodiversity is the variety of species and ecosystems on earth, and the ecological processes of which they are a part. Diverse living things pass on their characteristics to future generations by reproducing sexually and asexually.

34. Aiman Dhruva Tatianna Vidhi