Characteristics of Living things
Which characteristic of living things is shown when a plant grows toward sunlight?
Sensitivity (response to stimuli)
What is the basic unit of life?
Cell
Which organelle controls the activities of the cell?
Nucleus
Which specialized cell carries oxygen around the body and has no nucleus?
Red Blood Cell
What is the process by which plants make their own food?
Photosynthesis
Name two characteristics that all living things share.
growth, reproduction, respiration, excretion, nutrition, movement, sensitivity.
Which scientist first observed and named cells while studying cork?
Robert Hooke
Which organelle is known as the powerhouse of the cell?
Mitochondria
Which specialized cell carries electric messages throughout the body?
Nerve Cell
Name the two raw materials needed for photosynthesis
water and CO2
Why is a plastic toy moved by the wind not considered a living thing?
It does not carry out life processes.
State one principle of Cell Theory.
All living things are made of cells / Cells are the basic unit of life / All cells come from pre-existing cells.
Which plant cell structure provides support and protection?
Cell wall
What adaptation helps sperm cells move toward the egg?
A tail (flagellum)
What gas is released during photosynthesis?
O2
Which characteristic of life allows organisms to produce offspring?
reproduction
What is the main difference between unicellular and multicellular organisms?
Unicellular organisms have one cell that carries all live processes; multicellular organisms have many cells.
What is the function of the vacuole?
Stores water, nutrients, and waste materials.
Why are root hair cells long and thin and contain a lot of mitochondria?
Root hair cells are long and thin to provide a large surface area for absorbing water and mineral salts from the soil. They contain many mitochondria to release energy through respiration, which is needed for the active transport of mineral ions from the soil into the root hair cell.
What is the role of chlorophyll in the process of photosynthesis?
Chlorophyll is a green pigment found in chloroplasts that absorbs light energy from the Sun. This light energy is used to drive the process of photosynthesis, allowing the plant to produce glucose (food) from carbon dioxide and water.
Explain why a seed is considered living even when it appears inactive.
It can germinate, grow, and carry out life processes.
Explain why a unicellular organism can survive on its own.
A unicellular organism can survive on its own because it is made up of a single cell that carries out all the life processes necessary for survival. This one cell can obtain nutrients, remove waste, grow, respond to its environment, reproduce, and carry out other functions needed to maintain life without the help of other cells.
Name the organelle that contains chlorophyll and carries out photosynthesis.
Chloroplast
Explain why palisade mesophyll cells contain a large number of chloroplasts.
Palisade mesophyll cells contain many chloroplasts because they are the main site of photosynthesis in the leaf. The large number of chloroplasts allows the cells to absorb more sunlight, which is needed to make food (glucose) for the plant through photosynthesis. This helps the plant produce enough energy and nutrients for growth and survival.
Explain what happens to a plant if it is kept in complete darkness for several days.
If a plant is kept in complete darkness for several days, it cannot carry out photosynthesis because there is no light energy available. As a result, the plant stops producing glucose, which is its source of food. The plant must use up its stored food reserves to survive, and over time it becomes weak, loses its healthy green color, and may eventually die if light is not restored.