Скачать с ютуб Science Grade 6 First Term Concept 1 1 Lesson 3 в хорошем качестве

Science Grade 6 First Term Concept 1 1 Lesson 3

• Living organisms are classified according to number of cells into Unicellular organisms Multicellular organisms - They are living organisms that their bodies consist of only one cell. - Example: bacteria - They are living organisms that their bodies consist of many cell. - Example: Humans, plants & animals. G.R Bacteria are unicellular organisms. o Because their bodies consist of one cell only. A horse is one of the multicellular organisms. o Because its body consists of many cells. The structure multicellular organisms Level Definition Examples Cell The basic unit of life Stomach cell Tissue a group of similar cells that do the same function Stomach tissue Organ A group of different tissues to do its own function. Stomach System A group of different organs to do a certain function Digestive system Entire organism The human body is composed of a group of different systems. Human Cell parts The main parts of most animal and plant cell: • Cell membrane • Cytoplasm • Nucleus • Organelles ❶Cell Membrane Location It surrounds the cell from outside (especially the animal cell) Function 1. It protects the cell. 2. It controls the substances that can enter or leave the cell through the "selective permeability" feature ❷Nucleus Location At the center of the cell Function It controls all the cell activities such as : 1) Formation of proteins. 2) Cell division to form new cells. ❸Mitochondria 1) They are known as the "powerhouses" of the cell 2) They provide the cell the energy by converting sugar into energy by (Cellular respiration ) process ❹Cytoplasm It is the gelatinous liquid (thick liquid) inside the cell in which all other cell parts float. ❺Endoplasmic reticulum It helps in assembling (collecting) and transporting proteins inside the cell to build and repair the cell. ❻Golgi apparatus It helps in packing and transporting different materials: - between the cells. - out of the cell Notes ①The plant cell is surrounded by a cell wall from outside. ②The cell wall is made up of a substance called cellulose. ④A special type of plant cell has the ability to make the photosynthesis process as it contains special called chloroplasts. ⑤The human body contains about 40 trillion cells 1. The human body is composed of ………………cells. a. 40 hundred b. 40 thousand c. 40 million d. 40 trillion 2. All the following are from the cells found in the animal body, except the ………………. a. blood cells b. xylem cells c. bone cellS. d. muscle cells 3. The tissue is a set of similar……………………. a. systems b. cells b. organs c. cells d.organells 4. All the following are considered organs, except the…………… a. lung b. heart c. stomach d. muscle tissue 5. All the following organisms are examples of multicellular organisms, except………………. a. human b. horse c. bacteria d. apple tree 6. The systems that keep a multicellular organism alive are divided into levels. a. one b. four c. three d. five 7. All the following parts are from the main parts of animal cell, except……………. a. cell membrane b. cell wall b. cell wall d. nucleus 8. The gelatinous liquid which is found inside the cell is known as……………….. a. nucleus. b. cytoplasm c. cell membrane d. cell wall 9. Plant cell has the ability to make the photosynthesis process due to the presence of…………….. inside it a. mitochondria b. chloroplasts c. nucleus d. cytoplasm 10. The organelles which provide the cell with the needed energy are called………………. a. endoplasmic reticulum b. mitochondria c. Golgi apparatus d. cell membrane