Unit 05 The Biosphere: Life on Earth and Cell Characteristics

Unit 05 The Biosphere

Doña Macarena Arechavaleta Janini Biology 2º PAIUnit 5 The Biosphere

1. Life on Earth
2. Living and non- Living things
3. Life processes

   a) Nutrition b) Respiration. c) Excretion. d) Growth e) Sensivity and movement f) Reproduction

4. Cell Characteristics
5. Prokaryotic Cells
6. Eukaryotic Cells
7. The Five kingdoms: Monera, Protist, Fungi, Plant and Animal

Life on Earth

• Earth's distance from the Sun (150 million kilometres) is ideal for life. The temperature and amount of light are optimal.
• Earth's atmosphere filters out harmful ultraviolet radiation from the Sun. It also helps to regulate Earth's temperature.
• Thanks to the average temperature almost all the water on Earth is in liquid state. This is essential for all life on the planet.
• Earth's atmosphere contains oxygen, which living beings needs for respiration.
• Also, carbon dioxide, which along with water and sunlight, is vital for photosynthesis in algae, plants and some bacteria that produce oxygen during this process.
• Earth is home to diverse living organisms. Some are small and simple, while others are large and complex. Coral reefs and rainforests have a huge variety of species.

Living and Non-Living Things

• Both living and non-living things are made up of matter, they are made up of tiny units called atoms. Atoms join together to form molecules. In living things are called biomolecules.
• There are two types of biomolecules:
  • Inorganic biomolecules, water and mineral salts, are found in both living and non-living things.
  • Organic biomolecules, such as carbohydrates, lipids, proteins and nucleic acids (DNA/RNA) are only found in living things.
• All living things:
  • have similar chemical composition.
  • are composed of tiny individual cells.
  • perform seven life processes: nutrition, respiration, excretion, growth, movement, sensitivity and reproduction.

Inorganic and Organic Biomolecules

Sales minerales Agua Es la biomolécula más abundante en todos los seres vivos. Regulan procesos vitales y componen algunas estructuras del organismo. Agua Lípidos Glúcidos Proteínas Ácidos nucleicos Ácidos nucleicos 70% 3 % 4,5 % 8 % 7% 7,5 % Lípidos Glúcidos Proteínas Aportan energía para las actividades vitales y proporcionan aislamiento térmico. Desempeñan numerosas funciones, como participar en la contracción muscular. a Minerales Contienen la información para el funcionamiento de los organismos.

Life Processes

a) Nutrition is how living things obtain energy. They break down or decompose substances from the environment. b) Respiration c) Excretion d) Growth e) Sensivity and movement f) Reproduction

Nutrition Types

There are two types of nutrition

• Autotrophic nutrition: autotrophs organisms change inorganic matter into organic matter by means of photosynthesis.
• Plants are autotrophs. They use the Sun's energy to perform photosynthesis.
• Heterotrophic nutrition: heterotrophs organisms feed on other living things, they obtain both inorganic and organic nutrients from their environment.
• They include herbivores, carnivores, omnivores and saprotrophs, such as fungi.

Life Processes: Respiration, Excretion, Growth

b) Respiration is how living things release energy from food. c) Excretion is how living things eliminate waste materials. d) Growth: the size and shape of a newly born living organism change dramatically over time.

• They grow: Their size and weight increase.
• They develop: they experience changes in their body structure and function over the course of life.
• The abrupt change that some organisms-such as butterflies and frogs- undergo during their development is called metamorphosis Some organisms, such as trees, continue to grow throughout their entire life. Most animals, however, reach certain dimensions and stop growing.

Life Processes: Sensitivity and Movement

• e) Sensitivity: all living things are sensitive to changes, such as:
  • temperature, when it gets warmer or colder.
  • humidity, when the air becomes wetter or drier.
  • hunger, when a living thing needs food.

  These changes are called stimuli. Living things respond to stimuli by reacting and adapting to the changes.

• f) Movement: all living things can move in response to stimuli.
  • Plants can move in response to light, gravity and chemicals.
  • Animals can use their muscles to move in response to stimuli.

Reproduction

• Asexual reproduction: a single organism creates new individuals. The new organisms are identical to the parent. Many microoganisms reproduce by fission. They divide to form two new daughter cells.

3.6. Reproduction is the life process that creates new organisms.

• Sexual reproduction: two organisms of different sexes create new individuals. The parent organisms produce sex cells called gametes. Male and female sex cells join to produce offspring with traits from both parents.

3.6. Reproduction is the life process that creates new organisms.

Cell Characteristics

• Unicellular organisms, such as protozoans and bacteria, are made up of one cell.
• Multicellular organisms, such as plants and animals, have many cells.
• All cells have three basic parts:
  • The cell membrane protects the cell and lets some substances pass through.
  • The cytoplasm is a viscous liquid inside the cell. Chemical reactions take place here. It contains different types of organelles which perform specific tasks within the cell.
  • Genetic material called DNA (deoxyribonucleic acid) contains information that controls the cell. It passes to the cell's offspring.

Prokaryotic Cells

• These are the simplest type of cell. They do not have a defined nucleus. In fact, the word 'prokaryotic' means 'before a nucleus'.
• The genetic material (DNA) is not located in one place. It is dispersed in the cytoplasm.
• They have a rigid cell wall. It protects the cell and gives it shape. Inside the cell wall, there is a plasma membrane.
• Bacteria are prokaryotic organisms. They are also unicellular.
• Some bacteria have a long tail called a flagellum. They use the flagellum to move around.

Prokaryotic Cell (Bacteria) Diagram

Cell Wall Plasma membrane Pilli Capsule Genetic material 2 Ribosomes Cytoplasm Flagellum

Eukaryotic Cells

• Eukaryotic cells have a true nucleus. In fact, the word 'eukaryotic' means 'with a true nucleus'.
• The genetic material (DNA) is located inside the nucleus, which has a double membrane.
• There are two types of eukaryotic cells: plant cells and animal cells.
• Plant and animal cells have a cell membrane and cytoplasm. Plant cells also have a cell wall.
• Plant and animal cells have some organelles in common, such as vacuoles and mitochondrion. Animal cells also have centrosomes. Plant cells have chloroplasts, which contain chlorophyll.

Animal Cell Diagram

Nucleus Cell membrane Small vacuole Golgi Body Ribosomes (produce proteins) Mitochondrion (Produce the energy required by the cell through cellular respiration) Centrosome (involved in cell division) Endoplasmic reticulum Ribosomes Cytoplasm

Plant Cell Diagram

Nucleus Cell membrane Cell wall (protective covering that gives the cell its shape) Ribosomes Endoplasmic reticulum Vacuole (stores food, minerals and water) Mitochondrion (Produce the energy required by the cell through cellular respiration) Golgi Body C Chloroplast (responsable for carrying out photosynthesis) Cytoplasm Plant cells are polygonal in shape

Animal and Plant Cell Comparison

Animal Cell plasma membrane cytoplasm nucleus Plant Cell nucleus cell wall plasma membrane chloroplasts cytoplasm vacuole

Identifying Organelles in Plant Cells

Identify the organelles of the plant cell in the diagram. V ¥ A V V V V VI

Identifying Organelles in Animal Cells

Identify the organelles of the animal cell the diagram. ¥ V V V V V

The Five Kingdoms Characteristics

• We can divide living things into five kingdoms: monera, protist, fungi, plant and animal.
• Monera kingdom:
  • They are prokaryotic and unicellular. They are usually bacteria.
  • They can be autotrophs or heterotrophs.
  • They mainly reproduce asexually. Some are mobile.
• Protist kingdom:
  • They are eukaryotes and they can be unicellular or multicellular.
  • They can be autotrophs (algae) or heterotrophs (protozoans).
  • They can reproduce asexually or sexually. Some are mobile.

The Five Kingdoms: Fungi, Plant, Animal

• Fungi kingdom:
  • They are eukaryotic, heterotrophic and unicellular or multicellular.
  • They reproduce sexually and asexually. They are not mobile.
• Plant kingdom:
  • They are eukaryotic, multicellular and autotrophic.
  • They reproduce sexually and asexually. Some produce flowers.
  • They can move but they are not mobile.
• Animal kingdom:
  • They are eukaryotic, multicellular and heterotrophic.
  • Most reproduce sexually. Some reproduce asexually.
  • They have sense organs and they are mobile.

Kingdom Classification Summary

Prokaryotic Eukaryotic Unicellular Multicellular Autotroph Heterotroph Reproduce sexually Reproduce asexually Monera Protist Fungi Plant Animal

• Monerans can exchange genetic material through conjugation. Some animal species, such as flatworms, can reproduce asexually.

7. The five kingdoms The 5 Kingdoms in Classification | Evolution | Biology | FuseSchool - YouTube

Physiological Criteria for Life Forms

Classify each of the following life forms as an autotroph or a heterotroph.

1. Mold
2. Water lily
3. Human being
4. Acacia
5. Mushroom
6. Kelp
7. Anabaena
8. Rat
9. Yeast
10. Elodea
11. Tomato plant
12. Snail

Talking about Prokaryotes

Select a suitable option to complete the state- ments below.

I. As a rule, prokaryotic cells are eukaryotic cells. smaller than equal in size to larger than

Il. Prokaryotic cells do not form organisms. one-celled many-celled one-celled nor many-celled

III. Prokaryotic cells have a bacterial wall the plasma membrane. around inside replacing

IV. Contrary to eukaryotic cells, prokaryotic cells have no membrane cytoplasm nucleus

V. are prokaryotic cells. Protozoa One-celled algae Bacteria

Talking about Eukaryotes

Select a suitable option to complete the state- ments below.

I. Eukaryotic cells form organisms. many-celled and one-celled many-celled one-celled

Il. In contrast with prokaryotes, eukaryotic cells have a nucleus bacterial wall cell membrane

III. The cytoplasm of eukaryotic cells contains substances dissolved in water and organelles I substances dissolved in water organelles

IV. Eukaryotic cells are ................... prokaryotic cells. smaller than equal in size to larger than

V. Animals and plants are organisms. eukaryotic and many-celled I eukaryotic and one-celled prokaryotic