Science 7 Grade: Cells And Heredity (Chapter 2, Sect. 1 & 2)

Front 1

What is photosynthesis?

Back 1

The process by which a cell captures energy in sunlight and uses it to make food.

Front 2

How do living things obtain energy?

Back 2

Either directly or indirectly from the energy of sunlight captured during photosynthesis.

Front 3

How does grass obtain energy?

Back 3

Grass obtains energy directly fron sunlight because it makes its own food during photosynthesis.

Front 4

How does a zebra obtain energy?

Back 4

A zebra obtains energy indirectly by eating the grass. Energy has beeen stored in the grass.

Front 5

What is autotroph?

Back 5

An organisim that makes its own food.

Plants make their own food through the process of photosynthesis.

Front 6

What is heterotroph?

Back 6

An organism that cannnot make its own food.

Animals (zebra) cannot make its own food.
Fungi absorb their food from other organisms.

Front 7

How do autotrophs get their food?

Back 7

They make their own food using sunlight and photosynthesis.

Front 8

How does the sun supply heterotrophs with energy?

Back 8

Heterotrophs get energy by eating plants or other animals that eat plants.
Plants gether theri energy from sunlight, so heterotrophs get their energy from sunlight indirectly.

Front 9

Where are houseplants usually placed?

Back 9

Near a window or under plant lights.

Front 10

What happens if a houseplant doesn't get enough light?

Back 10

They lose their leaves, turn yellow and may die.

Front 11

Why do plants need light?

Back 11

Plants use light energy to make food.

Front 12

What happens during photosynthesis?

Back 12

There are two stages:
--capturing the sun's energy;
--producing sugars.

Front 13

What is the energy captured in the first stage used for?

Back 13

To produce sugars in the second stage.

Front 14

What pigment in chloroplasts absorbs light?

Back 14

Both chlorophyll and solar cells absorb light energy and use it to power a process.

Front 15

What happens in the second stage of photosynthesis?

Back 15

Water and carbon dioxide combine chemically to form sugars, and oxygen is released.

Front 16

How is chlorophyll like a solar cell?

Back 16

Both chlorophyll and solar cells absorb light energy and use it to power a process.

Front 17

How are roots and stomata important for photosynthesis?

Back 17

Roots take up water, and stomata take in carbon dioxide, both of which are needed for photosynthesis.

Front 18

What role do you think the guard cells play?

Back 18

They regulate what enters the stomata.

Front 19

When do you think the stomata are usually open?

Back 19

During the day when light energy is available for photosynthesis.

Front 20

What make plants green?

Back 20

Chloroplasts contain the green pigment chlorophyll.

Front 21

What happens during photosynthesis?

Back 21

Plants and some other organisms use energy from the sun to convert carbon dioxide and water into oxygen and sugars.

Front 22

Photosynthesis takes place in how many stages? What is the first stage?

Back 22

Two stages.
Capturing the sun's energy.
In plants, this energy-capturing process occurs mostly in its leaves.

Front 23

How does the green color in plants occur?

Back 23

The green color comes from pigments, colored chemical compounds that absorb light.The main photosynthetic pigment in chloroplasts is chlorophyll.

Front 24

How does chlorophyll in plants functions?

Back 24

Similar to the solar "cells" in a solar powered calculator.
Chlorophyll captures light energy and uses it to power the second stage of photosynthesis.

Front 25

What is the second stage in photosynthesis?

Back 25

Using energy to make food.
The cell uses the captured energy to produce sugars.
The cell needs two raw material for this stage: water (H2O) and carbon dioxide (CO2)

Front 26

How does the second stage work?

Back 26

In plants, the roots absorb water from the soil
Water moves up through the plant's stem to the leaves.
Carbon dioxide is one of the gases in the air and it enters the plant through the stomata.

Front 27

What is the stomata?

Back 27

Small openings on the undersides of leaves

Front 28

What is the photosynthesis equation?

Back 28

6 CO2 + 6 H2O yields C6 H12 O6 + 6 O2 or
carbon dioxide + water (light energy) yields a sugar + oxygen

Front 29

Explain the photosynthesis equation.

Back 29

raw materials are: six molecules of carbon dioxide and six molecules of water yield one molecule of a sugar and six molecules of oxygen.

Front 30

What does the arrow mean in the photosynthesis equation?

Back 30

Yields or connects the raw materials to the produce. Light energy or the chemical reaction is written above the arrow.

Front 31

What is respiration?

Back 31

It is the process by which cells obtain energy from glucose.

During respiration, cells break down simple food molecules such as sugar and release the energy they contain.

Front 32

Do plant cells and animals cells respire?

Back 32

Yes, all living things need a continuous supply of energy, the cells of all living things carry out respiration continuously.

Front 33

Some students may think that soil provides plants with food. It this true or false.

Back 33

This is only partially true. The soil provides one of the raw materials for plants to make food--water. However, plants produce their own food from water plus carbon dioxide and the energy from sunlight; plants do not tkae in food.

Front 34

Vigorous exercise, such as hiking or basketball requires a lot energy.

Back 34

Where does the energy come from?
Food can provide your body with energy.

Front 35

What does a fire need to burn?

Back 35

Fuel and oxygen

Front 36

What is released when fuel is burned?

Back 36

Energy in the form of heat and light. A similar chemical process, called respiration, "burns" food molecules in cells. Like combustion, respiration uses fuel and oxygen to produce energy. The fuel comes from food, and the energy is used for cellular functions.

Front 37

What is respiration?

Back 37

The process that releases energy from food.

Front 38

Why is respiration important to cells?

Back 38

It provides cells with the energy they need to carry out their functions.

Front 39

What happens in the first stage of respiration?

Back 39

Glucose is broken down into smaller molecules and a small amount of energy released.

Front 40

What happens in the second stage of respiration?

Back 40

The smaller molecules are broken down into even samller molecules and a large amount of energy is released.

Front 41

Why do you think that musecle cells have many mitochondria?

Back 41

The second stage of respiration, which produces lots of energy, takes place in the mitochondria. The supply a great amount of energy for movement.

Front 42

What is respiration?

Back 42

Respiration is the process by which cells obtain energy from glucose.

Front 43

What happens during respiration?

Back 43

During respiration, cells break down simple food molecules such as sugar and release the energy they contain.

Front 44

Explain respiration.

Back 44

Because lliving things need a continuous supply of energy, the cells of all living things carry out respiration continuously.

Front 45

Do plant cells and animal cells respire?

Back 45

Yes

Front 46

What is the respiration equation?

Back 46

C6 H12 O6 + 6 O2 6 CO2 +
sugar oxygen carbon dioxide

6 H2O + energy
water

Front 47

Where is energy stored and how is it released?

Back 47

It is like a savings account. Energy stored in cell is something like money you put in a saving saccount in a bank. When you want to buy something, you withdraw someof the money.

Front 48

How do cells use energy?

Back 48

Cells store and use energy in a similar way. During photosynthesis, plants capture the energy from sunlight and "save" it in teh form of carbohydrates, including sugars and starches.

Front 49

How are means like a savings account?

Back 49

When you eat a meal, you add to your body's energy savings account. When cells need energy, they
"withdraws" it by breaking down the carbohydrates in the process of respiration.

Front 50

Respiration has two meanings. One is connected with the lungs.

Back 50

You have probably used it to mean "breathing," moving air in and out of your lungs. The respiration that takes place inside the cell is different.

Front 51

The other meaning of respiraiton is connected with the cells.

Back 51

The respiration process that takes place inside cells is sometimes called cellular respiration.

Front 52

What are the two stages of respiration? What is the first stage?

Back 52

The first stage takes place in the cytoplasm of the organism's cells. Molecules of glucose are broken down into smaller molecules. Oxgyen is not

Front 53

What is the second stage of respiration?

Back 53

The second stage of respiration takes place in the mitochondria. There, the small molecules are broken down into even smaller molecules.These chemical reactions require oxygen, and they release a great deal of energy. This is why themitochondria are sometimes called the "powerhouses" of the cell.

Front 54

See figure 7. Trace the steps in the breakdown of glucose.

Back 54

Energy is released is both stages.