Cells Flashcards
What is the definition of cells?
Cells are the smallest unit of an organism.
How can you see cells?
Cells can be seen through a microscope.
Describe the shape of an animal cell and name four of the components found in an animal cell.
Animal cells have an irregular shape. The four components that can be found in an animal cell are Nucleus, A Cell Membrane, Cytoplasm and Mitochondria (many)
What is the function of a Nucleus?
Nucleus controls the cell and contain genetic materials for new cells.
What is the function of Cytoplasm?
Cytoplasm is a ‘jelly like’ substance where the chemical reactions in a cell happens.
What is the function of a Cell Membrane?
Cell membrane is a barrier that controls the in and out movement of the cell.
What is the function of Mitochondria?
Mitochondria is where respiration occurs.
What is respiration?
Respiration is a chemical reaction that transfers energy.
Describe the shape of plant cells and name the 7 components of a plant cell.
Plant cells have a more regular structure. The 7 components of a plant cell are Nucleus, a Cell Membrane, Mitochondria, Cytoplasm, a Vacuole, a Cell Wall and Chloroplasts.
Name the cell components that can only be found in a plant cell.
Vacuole, a Cell wall, and Chloroplasts
State the function of a cell wall and what it is made of.
Cell wall strengthens the cell and provide support. It is made of a tough fibre called cellulose, which makes the wall rigid.
State the function of a vacuole and what it contains.
Vacuole contains a watery liquid called cell sap. It keeps the cell firm.
State the function of chloroplasts and what it contains.
Chloroplasts is where photosynthesis happens. It contains green substance called chlorophyll which traps energy from the sun.
What are specialised cells?
Specialised cells are cells that changed their shape and structure that are suitable to carry out a particular job.
Give 5 different types of specialised cells.
Nerve cell, Red blood cells, Sperm cells, Leaf cells and Root hair cells.
State the function of nerve cells and describe the structure.
Nerve cells carry electrical impulses around the body. Its long and thin structure have connections at the end which allows them to transmit messages around the body.
State the function of red blood cells and describe its structure. What component does any other cells have but red blood cells doesn’t?
Red blood cells transport oxygen around the body. they contain haemoglobin; a red pigment that binds to oxygen. They have a disc-like shape which increase their surface area to carry oxygen. Red blood cells have no nucleus.
State the function of a sperm cell and describe its structure.
Sperm cells carry male genetic material. They have a streamlined head and a long tail to swim and move through a liquid.
State the function of leaf cells and describe its structure. What is its scientific name?
Leaf cells are known as palisade cells. They are found near the top of a leaf to carry out photosynthesis. The cells are long, thin and packed with chloroplasts. They have a large surface area for absorbing solar energy.
State the function of root hair cells and describe its structure.
Root hair cells absorb water and nutrients from soil. The root hair creates a large surface area for easier absorption. The cells have no chloroplasts since there’s no sunlight underground to carry out photosynthesis.
How did diffusion happen in plant cells?
Water diffuses into the plant through the root hair cells. Water molecules move from the soil into the root hair cells and travels from the root hair cells into other cells in the plant.
What happens to the vacuole if the plant doesn’t receive sufficient supply of water?
The vacuole shrinks and the plant will wilt. (This is because water fills up tue vacuole and pushes the cell wall to make the cell rigid. This helps the plant to stay upright)
What is a unicellular organism?
An organism that only contains one cell.
Name 2 types of a unicellular organism.
Amoeba and Euglena
Describe the structure of Amoeba and where it can be found.
Amoeba has no fixed shape and move by changing the shape of their body. They are found in fresh water, salt water, wet soil and sometimes inside animals.
How and what does Amoeba eat?
Amoebas eat algae, bacteria, and plant cells. They eat by surrounding tiny particles of food and forming a food vacuole; known as engulfing.
How does Amoebas reproduce?
Amoebas divide by binary fission (splits itself into two cells). The nucleus in the cell divides first, followed by the cytoplasm.
Describe the structures of euglena and where it can be found.
Euglena has an oval shape body with a flagellum (tail) that spins to move towards light. It has an eye spot which detects light. Euglenas can be found in fresh water.
What is the difference between Amoebas and Euglenas?
Euglena has chloroplasts which causes them to look green. They can trap solar energy to make food by photosynthesis.
How and what does Euglenas eat?
When a euglena doesn’t have enough sunlight to make food, they engulf microorganisms such as bacteria and algae.
How does Euglenas reproduce?
Euglenas reproduce by binary fission (splits itself into 2 cells)
What is a multicellular organism and how does it work?
Multicellular organism is an organism that made up of many cells. It contain organ systems to perform life processes.
State the levels of organisation in a multicellular organism.
Cells, Tissues, Organs, Organ system, Organism
Give examples of cells.
Nerve, muscle, red blood cells, root hair and leaf cells.
What is the function of a tissue?
Tissue is a group of similar cells that work together to perform a certain function.
Give an example of animal tissue.
Muscle cells : they contract together to make the body move.
or
Nerve cells: they work together to transmit messages around the body
Give an example of a plant tissue.
Xylem : tubes that carry water around the plant
What is an organ?
An organ is made up of different tissues that work together to perform a certain function.
State 3 examples of an organ.
Brain, liver, heart, lungs, stomach, kidney, bladder, intestine
Stem, leaf, root
What is an organ system?
Organ system is a group of different organs that work together to perform a certain function.
State and explain one example of an organ system.
Circulatory system : transport materials around the body in the blood.
Respiratory system : Takes in oxygen and removes carbon dioxide.
Reproductive system : Produces new organisms.
Does plants classified as an organ system?
Plant structure is mainly organised into organs or tissues but flowers are an organ system. They contain both male and female sex organs, which form the reproductive system.
State one example of a multicellular organism.
Humans, animals (dogs, cows, cats), trees
