PBL Assignment

1. PBL Assignment By: Amna Ben Khaled, Sameera Hassan, and RabiaIkram

2. WHAT IS BIODIVERSITY? Biodiversity is all the different species, ecosystems and the ecological processes they’re part of.

3. Explain The 5 Components of Biodiversity? 1. Ecosystem diversity--there are many different types of ecosystems (streams, marshes etc) 2. Community diversity--populations of different species living within a community 3. Species Diversity--there are many variation within a particular species 4. Genetic Diversity--there is a variety of genetic material in all living things. 5. Species Distribution Diversity--plant and animal species are not evenly distributed throughout the various ecosystems on Earth

4. What area of the Earth do we find the most biodiversity? Areas closer to the equator (tropical rainforests) Why are coral reefs called “the Amazons of the oceans?” In the ocean, coral reefs are the most diverse areas (just like the Amazon rainforest on earth).

5. What does interdependence mean? Interdependence is when a species is dependent on other species in its environment. What is an important example of interdependence found in nature? Food webs and food chains (predator/prey) are examples of interdependence.

6. 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's an association between members of different species. 1. Commensalism-- one organism benefits and the other isn’t affected (bird’s nest and tree, whale and barnacles).

7. 2. Mutualism—this is where both organisms benefit (bee and flower, clown fish and anemones). 3. Parasitism--one organism benefits and the other is harmed (mosquitoes and humans). Mmm, syrup!

8. What is a niche and why are they important? A niche describes the role of an organism in the ecosystem. An organism's niche includes: • What it eats • What eats it • Its habitat • Nesting site, range and habits • What effect it has on the other populations • What effect it has on the environment Niches allow many species to exist in the same location.

9. Name an ecosystems, the animals that live in it and the niches they would fill. Arctic Tundra Can Niches Change? Niches may change depending on the environment in which it lives as well as the organisms a species inter-relates with.

10. What is resource partitioning? Resource partitioning happens when two or more species need the same thing to survive. Since they have different niches, they can get that material from different places and split up the resources so there’s no competition. For example, there might be three birds that live in the same tree and eat the same thing. But since they have different niches, they get their food from different parts of the tree. That way they can each divide the resource amongst themselves and there’s no competition.

11. What is Variability? Variability is the variation of different species in an environment. What is Natural Selection? Natural selection is when the environment selects which individuals will survive and reproduce.

12. How Does Natural Selection Relate to Variability?  Variability allows animals in the same environment to have different characteristics. Natural selection may kill some of the animals, but because of variability others will still continue to live and reproduce, and their offspring will have certain characteristics.

13. Describe why variation is important in helping organisms deal with change in the environment? Variation is when all organisms are different. If there's a change in the environment some species will die while most will live. If they were all the same, whenever there was a shift in the environment they all could die since they’re made up of the exact same genes and will be affected in the exact same way by a disaster.

14. Explain the difference between heritable and non-heritable traits and give some examples of each. Heritable characteristics are passed on from generation to generation. Examples are eye colour, hair colour and skin type.  Non-heritable are learned; they are not necessarily passed on from generation to generation. Examples are ability to play instruments and artistic abilities.

15. How Can The Environment Change Some of Your Characteristics? The colour of your skin changes due to sun exposure. Your height and weight are influenced by your diet.

16. Explain the difference between discrete and continuous variation and give some examples of each. Discrete variation is a defined form. It's "either" this form "or" that form. Examples are being albino (you can “either” have pigmentation in your skin “or” you cant) and having earlobes that “either” are attached “or” not. Continuous variation is when there are many different variations in characteristics. Examples are shoe size and height.

17. Explain what asexual reproduction means and explain the four types of asexual reproduction with examples.  Asexual reproduction involves one parent and the offspring is an exact copy of that parent. The four types are: • Binary Fission--happens in single celled organism (the cell splits into 2 identical cells). eg bacteria, amoeba and algae. 2. Budding--Parent organism produces a bud which detaches from the parent and becomes a self sufficient individual. eg hydra, yeast and coral.

18. 3. Spore production—spores are similar to seeds and are produced by the division of cells in a parent. Each spore turns into an individual. eg fungi, molds and ferns.  4. Vegetative reproduction--is the reproduction of a plant not involving a seed. This includes cuttings, runners, suckers and tubers. eg. potatoes strawberries, and aspen trees.

19. Give a scientific explanation of sexual reproduction. It involves two individual organisms. The offspring has a mix of characteristics, half of one parent and half of the other. It doesn’t always involves female and male parents.

20. What special cells are involved in sexual reproduction?  Gametes (reproductive cells that join with other gametes during reproduction).

21. In animals, what are the specialized cells called that are involved in sexual reproduction and what do they produce? Male gametes called sperm cells and female gametes called egg cells. They form a fertilized combo of cells called a zygote. The zygote begins to divide into two and that keeps happening until it eventually becomes an embryo. The embryo becomes a multicellular organism in a female or an egg in other animals.

22. Briefly describe how sexual reproduction works in plants. Use the proper names of the parts please. It involves gametes that turn into a zygote that forms an embryo. Pollination happens when the male gametes (pollen) moves from the anther to the stigma. The pollen (male gamete) then travels down the stigma to the ovule (female gamete). They then combine to form a zygote and then finally an embryo. Pollen is the male gamete. Ovule is the female gamete.

23. Briefly explain the three types of sexual reproduction in plants. • Cross pollination--when the pollen from one plant combines with the ovule of another. The plants are NOT identical to the parent. 2. Self pollination—the pollen from one plant moves to the ovule in the same plant. Plants are identical to parents. 3. Artificial pollination—flowers are pollinated by man.

24. Give one major advantage and disadvantage of both sexual and asexual reproduction. ASEXUAL Advantage—it can produce many organisms at once. Disadvantage: the organisms will be exactly the same (no variation. SEXUAL Advantage—lots of variation, if there’s a change in the environment some will die but others will still live Disadvantage—takes lots of time and energy

25. What are some examples of organisms that can reproduce both asexually and sexually? Many plants, sponges and yeasts can reproduce both ways. Aphids, slime molds, sea anemones and some species of starfish can reproduce both ways.

26. Now can you answer this question? • What is biological diversity, and by what processes do diverse living things pass on their characteristics to future generations? Biological diversity consists of all the different species and ecosystems, and the ecological processes they’re part of. Living things pass on their characteristics to future generations through sexual and asexual reproduction.