Biology Free Essays

Biology: 1. Living Things Please remember to photocopy 4 pages onto one sheet by going A3A4 and using back to back on the photocopier Syllabus OB38 Understand how to use a simple key to identify plants and animals, including vertebrates and invertebrates OB39 Investigate the variety of living things by direct observation of animals and plants in their environment; classify living organisms as plants or animals, and animals as vertebrates or invertebrates OB40 Identify the basic life processes and characteristics common to all living organisms: nutrition, respiration, excretion, growth, reproduction, movement and response OB41 Recall that living things are composed of cells, tissues, organs and systems, and understand that growth results from cell division Biology is the study of living things (called organisms) Biology is the study of living things (called organisms) Student Notes The living things which we are most familiar with are plants and animals. Plants| Animals| Make their own food| Do not make their own food| Do not move from place to place| Move from place to place| Have cell walls| Do not have cell walls| Animals can then be sorted into two groups: 1. We will write a custom essay sample on Biology or any similar topic only for you Order Now Vertebrates = Animals that have a backbone. Mammal, fish, bird, reptile, amphibian). 2. Invertebrates = Animals that do not have a backbone. (Spiders, worms, jellyfish, anemones, etc). Biology Keys A key in Biology is a set of instructions which help us to identify or classify an organism. The key on the right helps us to identify classify different types of vertebrates. Can you identify where humans fit into this map? Basic life processes and characteristics common to all living organisms All living things have 7 life processes or characteristics in common. These are: 1. Growth All living things can grow/increase in size. This happens through cell division where cells have the ability to make copies of themselves. 2. Movement All living things can move. Animals can walk, fly etc, plants move their parts. 3. Nutrition All living things must be able to take in material from their environment such as food, which is needed to produce energy. 4. Respiration All organisms must extract energy from the food that they consume. Aerobic respiration uses oxygen to obtain energy from food. 5. Excretion Getting rid of waste products from chemical reactions in the body. 6. Response Reacting to a stimuli or changes in the environment. 7. Reproduction The formation of new individuals. Organisms must be able to reproduce themselves or their species will become extinct. Cells, Tissues, Organs and Systems All organisms are composed of cells which form tissues which form organs which in turn form systems. All organisms are composed of cells which form tissues which form organs which in turn form systems. CellsTissuesOrgansSystems Cells Cells are the main building blocks of life, e. g. blood cells and skin cells. (We will look at them in detail in the next chapter). Tissues A tissue is made up of a group of similar cells which carry out the same function, e. . skin tissue and muscle tissue. Organs An organ is made up of different types of tissue working together, e. g. the heart and the lung. Systems A system is formed by a group of organs working together, e. g. the reproductive system and the digestive system. â€Å"It’s extraordinary that so much time is spent educating people about birth and sex, but so little about this equally profound thing [death] that happens to everyone. Paul Murray (Irish Hospice Foundation) Exam Questions 1. [2011][2009 OL][2007 OL] Name one invertebrate animal and one vertebrate animal 2. [2009 OL] 36 – 370 C86 – 870 C| i) Choose the correct temperature range of human body temperature from the list on the right. (ii) Give one reason for a change in body temperature. 3. [2008 OL] Letter| Key feature of organism| A| Four pairs of legs| B| Segmented body, no legs| C| Three pairs of legs| D| Eight to ten pairs of legs| The table shows a simple key used to identify some common organisms found in a habitat. In the case of any two of the organisms shown on the right, write the letter corresponding to a key feature given in the table above beside the organism which that best describes. 4. [2008 OL] Muscle| | Digestive system| | Heart| (i) Write the letter T opposite the name of a body tissue in the table on the right. (ii) Write the letter O beside the name of a body organ in the table on the right. Exam Solutions 1. Invertebrate: slug/ snail/ mussel/ bee/ wasp/ fly/ spider/ starfish/ prawn†¦ Vertebrate: fish/ lizard/ snake/ dog/ cat/ bird/ frog/ newt/ toad/ bat/ whale†¦ 2. (i) 36 – 370 C (ii) Illness / stress / pain / exercise 3. (i) A: Spider (ii) C: Wasp (iii) D: Caterpillar 4. (i) T: Muscle (ii) O: Heart Other Test Questions 1. List six characteristics of living things. . What is an organ made up of? 3. Define (i) sensitivity, (ii) reproduction, (iii) respiration and (iv) excretion. 4. Explain the term tissue. 5. What process do cells undergo to allow growth in organisms? 6. When discussing ‘Living Things’, why are so few people prepared to discuss ‘Death’? Is death natural or unnatural? How do most animals in ‘nature’ die? If another animal attacked a koala bear who would like to see win the fight? Why? Every single one of us will die someday – have you ever discussed your death with anyone? Has anyone else ever discussed their death with you? How to cite Biology, Papers Biology Free Essays Negative and positive feedback processes both occurs in the enzyme pathways. The difference between positive and negative feedback is that in negative feedback, the protein being produced by the enzyme or the protein produced as a result of a chain of proteins becomes very much concentrated. Consequently, the protein then inhibits the enzyme through placing themselves at the start of the chain. We will write a custom essay sample on Biology or any similar topic only for you Order Now The protein attachment places itself in an allotter site thereby changing the shape of the enzyme instead of changing the functional site where the protein would prevent the enzyme from including some other proteins (Werner, 1999). In the positive feedback, instead of inhibiting the reactions, it accelerates them. Positive feedback occurs when a certain enzyme is created and this particular enzyme signals the body to continue producing lots of that enzyme. Through this signals, the enzyme becomes its own catalyst in the process. When the loop begins, it moves with an accelerating speed until a larger feedback stops it. The greatest difference between the two is that, negative feedback manages to inhibit a reaction after the creation of a lot of products while positive feedback accelerates the process which produces the product (Werner, 1999). (b) Biological definition of a flower A flower is also referred to as bloom (blossom). This is the reproductive part located in the flowering plants. It can also be defined as a modified stem with reduced internodes and bearings. At the nodes, it has parts which may be highly modified leaves. Actually, the flower forms at the axis with an apical meristem that has its growth determinate. There are some biological means by which flowers attach themselves to the plants. The sessile flower is a term referred to those types of flowers that form at the axil of the leaf, but they do not have stems. The penduncle is the stem that holds one flower when it is produced. Incase of groups of flowers held by the penduncle, each stem holding the different flowers is referred to as the pedicel. The flowering stem forms the receptacle (torus). This is the terminal end of the stem (Stewart, 2004). The flower parts are arranged in four main parts or whorls. These parts are arranged in whorls on the torus. Flowering plants are classified under the division Magnoliophyta also referred as Angiosperms. Flowering plants are heterosporangiate meaning that they can produce both the female and the male reproductive spores. The male reproductive spores are referred as pollen and the female reproductive spores are called ovules. Both of these spores are produced by different organs although a typical flower (bisporangiate strobilus) contains both the organs. The flower performs the function of mediation between the male and female ovum. It allows the union of both ovums which leads to the production of seeds. The process commences with pollination and then fertilization. This processes lead to the formation and dispersal of seeds. Each flower is specifically designed to provide for effective transfer of pollen. For the higher plants, the dispersed seeds are the next generation. They are the primary source by which species of other generation could be dispersed to many different landscapes. Inflorescence refers to the process of grouping flowers. The Crateva religiosa is a very good example of a perfect flower. It has both the outer ring referred to as the stamen and the center referred to as the pistil (Stewart, 2004). How to cite Biology, Papers Biology Free Essays The n Ext par g h contain uses w the ear b king details bout he p o I nab art who t happen tom. Al feather putsches detection weatherboard. Two of the MO RSI Jumped ova rib a d n the ‘rd one, alarm day in chaw s, broke h arm in the strut lee to escape, dying later on. We will write a custom essay sample on Biology or any similar topic only for you Order Now The to r w mothers did NT fare much bet r. One of the m drowned IM d tell from the w gig t of her c anis; d the s condo e, v n though e WA rescue d an brought n board, w LU J pm over a d few says I term. Du to he a ND the conditions hey ad mob r , lots f hem did . Even so, the place w s get in v arc owed because â€Å"the numb r of peel brought n board GE TTYL Exec d those w did † (76). Two we KS later, who n et â€Å"prison c old ho n m re, the s IP a led own t he rive † and to he ocean (76). While at s , he condition s mob art SE m to less n a elite b for s me of the prisoner . Women had t Eire chaw NSA t eek of and were al owed t go n he up r deck, but only whew t weather since. The con Luda g par h lee vs. the r ad with a b err task . The p o I nab art h of â€Å"enough TTS p rot life† (76). A third of the p o I die on the cross Inning. Whew t near go t to his f anal destine o he wasn’t bled o stand up for a we k. Eve n though e ad survive deed the ordeal, despondent havening. Household tavern, defiantly words of histories looking ay:†leave bonfire years†(76). How to cite Biology, Papers