It s Alive!!! Or is it??? Book A, Chapter 1 Mrs. Armstrong

Transcription

1 It s Alive!!! Or is it??? Book A, Chapter 1 Mrs. Armstrong

2 It s Alive!! Or Is It? Table of Contents Section 1 Characteristics of Living Things Section 2 The Necessities of Life

3 Section 1 Characteristics of Living Things Bellringer What are four living and nonliving things that you interact with every day? How do you know whether each is living or nonliving? Do you know what the word inanimate means? If so, write out a definition. Does nonliving mean the same thing as dead? Explain your answer. Write your answers in your science journal.

4 Section 1 Characteristics of Living Things Objectives Describe the six characteristics of of living things. Describe how organisms maintain stable internal conditions. Explain how asexual reproduction differs from sexual reproduction.

5 Section 1 Characteristics of Living Things Living Things Have Cells All living things are composed of one or more cells. A cell is a membrane-covered structure that contains all of the materials necessary for life. Some organisms are made up of only one cell and some are made up of trillions of cells. In an organism with many cells, different kinds of cells perform specialized functions.

6 Section 1 Characteristics of Living Things Living Things Sense and Respond to Change A stimulus is anything that causes a reaction or change in an organism or any part of an organism. Homeostasis is the maintenance of a stable internal environment. Responding to External Change Organisms must respond to change in the external environment in order to maintain their homeostasis.

7 Section 1 Characteristics of Living Things Living Things Reproduce Organisms make other organisms similar to themselves. In sexual reproduction, two parents produce offspring that will share characteristics of both parents. In asexual reproduction, a single parent produces offspring that are identical to the parent.

8 Section 1 Characteristics of Living Things Living Things Have DNA The cells of all living things contain the molecule deoxyribonucleic acid, or DNA. DNA controls the structure and function of cells. The passing of traits through DNA is called heredity.

9 Section 1 Characteristics of Living Things Living Things Use Energy Organisms use energy to carry out the activities of life. An organism s metabolism is the total of all of the chemical activities that the organism performs.

10 Section 1 Characteristics of Living Things Living Things Grow and Develop All living things, whether they are made of one cell or many cells, grow during periods of their lives. Living things may develop and change as they grow.

11 Section 2 The Necessities of Life Bellringer What do you think your mass would be if there were no water in your body? What else besides water is your body composed of? Where do you think you get the minerals that make up your body mass? Record your answers in your science journal.

12 Section 2 The Necessities of Life Objectives Explain why organisms need food, water, air, and living space. Describe the chemical building blocks of cells.

13 Section 2 The Necessities of Life Water Your cells and the cells of almost all living organisms are approximately 70% water. Most of the chemical reactions involved in metabolism require water. Air Air is a mixture of several different gases, including oxygen and carbon dioxide. Most living things use oxygen in the chemical process that releases energy from food.

14 Section 2 The Necessities of Life A Place to Live All organisms need a place to live that contains all of the things they need to survive. Space on Earth is limited, so organisms are often in competition with each other. Food All living things need food. Food gives organism energy and the raw material needed to carry on life processes. Making Food Some organisms, such as plants, are called producers. Producers can make their own food by using energy from their surroundings. Taking Food Other organisms are called consumers because they must eat (consume) other organisms to get food. Decomposers are consumers that get their food by breaking down the nutrients in dead organisms or animal wastes.

15 Section 2 The Necessities of Life Putting It All Together All organisms need to break down that food in order to use the nutrients in it. Nutrients are made up of molecules. Molecules found in living things are usually made up of six elements: carbon, hydrogen, nitrogen, oxygen, phosphorus, and sulfur.

16 Section 2 The Necessities of Life Proteins Proteins are large molecules made up of amino acids. Making Proteins Organisms break down the proteins in food to supply their cells with amino acids that are then linked together to form new proteins. Proteins in Action Some proteins form structures that are easy to see. Other proteins help cells do their jobs. Proteins called enzymes start or speed up chemical reactions in cells.

17 Section 2 The Necessities of Life Carbohydrates Molecules made of sugars are called carbohydrates. Simple Carbohydrates Simple carbohydrates are made up of one sugar molecule or a few sugar molecules linked together. Complex Carbohydrates Complex carbohydrates are made of hundreds of sugar molecules linked together. Organisms store extra sugar as complex carbohydrates.

18 Section 2 The Necessities of Life Lipids Lipids are compounds that cannot mix with water. Phospholipids are the molecules that form much of the cell membrane. Fats and Oils Fats and oils are lipids that store energy. When an organism has used up most of its carbohydrates, it can get energy from these lipids.

19 Section 2 The Necessities of Life

20 Section 2 The Necessities of Life ATP Adenosine triphosphate, or ATP, is the major energycarrying molecule in cells. The energy in carbohydrates and lipids must first be transferred to ATP, which then provides fuel for cellular activities.

21 Section 2 The Necessities of Life Nucleic Acids Nucleic acids are large molecules made up of subunits called nucleotides. Nucleic acids are sometimes called the blueprints of life because they have all the information needed for a cell to make proteins. DNA is a nucleic acid.

22 Concept Map

23 Concept Map - Answers

24 It s Alive!!! Or is it?? The End

25 Standardized Test Preparation Reading Read each of the passages. Then, answer the questions that follow each passage. Passage 1 Organisms make other organisms similar to themselves. They do so in one of two ways: by sexual reproduction or by asexual reproduction. In sexual reproduction, two parents produce offspring that will share characteristics of both parents. Most animals and plants reproduce in this way. In asexual reproduction, a single parent produces offspring that are identical to the parent. Most singlecelled organisms reproduce in this way.

26 Standardized Test Preparation 1. In the passage, what does the term asexual reproduction mean? A A single parent produces offspring. B Two parents make identical offspring. C Plants make offspring. D Animals make offspring.

27 Standardized Test Preparation 2. What is characteristic of offspring produced by sexual reproduction? F They are identical to both parents. G They share the traits of both parents. H They are identical to one parent. I They are identical to each other.

28 Standardized Test Preparation 3. What is characteristic of offspring produced by asexual reproduction? A They are identical to both parents. B They share the traits of both parents. C They are identical to one parent. D They are usually plants.

29 Standardized Test Preparation 4. What is the difference between sexual and asexual reproduction? F the number of offspring produced G the number of parents needed to produce offspring H the number of traits produced I the number of offspring that survive

30 Standardized Test Preparation Passage 2 In 1996, a group of researchers led by NASA scientists studied a 3.8-billionyear-old meteorite named ALH These scientists agree that ALH84001 is a potatosized piece of the planet Mars. They also agree that it fell to Earth about 13,000 years ago. It was discovered in Antarctica in According to the NASA team, ALH84001 brought with it evidence that life once existed on Mars. Scientists found certain kinds of organic molecules (molecules containing carbon) on the surface of ALH These molecules are similar to those left behind when living things break down substances for food. When these scientists examined the interior of the meteorite, they found the same organic molecules throughout. Because these molecules were spread throughout the meteorite, scientists concluded that the molecules were not contamination from Earth. The NASA team believes that these organic compounds are strong evidence that tiny organisms similar to bacteria lived, ate, and died on Mars millions of years ago.

31 Standardized Test Preparation 1. How old is the meteorite named ALH84001? A 13,000 years old B millions of years old C 3.8 billion years old D 3.8 trillion years old 2. Which of the following would best support a claim that life might have existed on Mars? F remains of organisms G water H meteorite temperatures similar to Earth temperatures I oxygen

32 Standardized Test Preparation Interpreting Graphics The graph below shows an ill person s body temperature. Use the graph below to answer the questions that follow. 1. A fever is a spike in temperature. On which day does this person have a fever? A Sunday B Monday C Wednesday D Saturday

33 Standardized Test Preparation 2. A body with a fever is often fighting an infection. Fevers help eliminate the pathogens that cause the infection. According to the chart, when does this person probably have the highest fever? F Sunday G Monday H Wednesday I Saturday

34 Standardized Test Preparation 3. What is the highest temperature that this fever reaches? A 37 C B 38 C C 39 C D 40 C

35 Standardized Test Preparation 4. What is probably this person s normal body temperature? F 37 C G 38 C H 39 C I 40 C

36 Standardized Test Preparation Math Read each question, and choose the best answer. 1. An aquarium is a place where fish can live. What is the volume of the aquarium shown below? A 0.25 m B 0.25 m 2 C 0.25 m 3 D 0.52 m 3

37 Standardized Test Preparation 2. The cost of admission to a natural history museum is $7 per adult. What is the total cost of admission for a group of five adults? F $25 G $35 H $45 I $55

38 Standardized Test Preparation 3. Lee biked 25.3 km on Monday, 20.7 km on Tuesday, and 15.6 km on Wednesday. How many kilometers did Lee bike during those three days? A 66.1 km B 61.6 km C 51.6 km D 16.6 km

39 Standardized Test Preparation 4. Laura collected 24 leaves. One-third of the leaves were oak leaves. How many oak leaves did Laura collect? F 6 G 8 H 12 I 24