SCIENCE 7B LESSON

Question 1

photosynthesis

Answer 1

the process by which plants make food: plants convert carbon dioxide and water to oxygen and glucose

Question 2

atmosphere

Answer 2

A mixture of gases that surround a planet, moon, or other space object

Question 3

green house effect

Answer 3

the energy absorbed and reradiated by the atmospheric gases through the greenhouse effect.

Question 4

ultraviolet radiation

Answer 4

One type of solar radiation that can harm life is ultraviolet. This is harmful because it can damage the genetic material of an organism.

Question 5

ozone

Answer 5

earth has a protective ozone layer that blocks most ultraviolet radiation before it reaches Earth’s surface. This ozone layer contains ozone gas in addition to other atmospheric gases.

Question 6

orbit

Answer 6

is the path that a body follows as it travels around another body in space.
Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus and Neptune orbit the Sun

Question 7

solar system

Answer 7

a collection of large and small bodies that orbit the central star

Question 8

gravity

Answer 8

is the force of attraction between objects due to their masses and the distances between them.

Question 9

launch

Answer 9

the process of setting a rocket or spacecraft in motion. Gas, often burning fuel, is used to launch a rocket

Question 10

space shuttle

Answer 10

a reusable spacecraft glides to a landing like an airplane

Question 11

spacecraft

Answer 11

is a crewed or uncrewed space vehicle that is designed to be placed in orbit around Earth or on a path in space.

Question 12

reentry angle

Answer 12

a steep angle causes the craft to be overheated, a shallow angle will cause it to bounce back off the atmosphere into space

Question 13

orbital velocity

Answer 13

the minimum velocity and object in order to go in orbit around earth or another object

Question 14

asteroid

Answer 14

a belt of relatively small objects

Question 16

weightlessness

Answer 16

is the apparent loss of weight of an object that is falling freely due to gravity

Question 17

Radiation

Answer 17

radiation in space includes electromagnetic radiation and highly charged particles that can damage DNA and tissues. This cause the risk of cancer.

Question 18

Meteoroids

Answer 18

include small particles of dust or rock that are moving at high speeds in space, they can cause serious damage if they collide with a spacecraft or an astronaut working outside the spacecraft.

Question 19

Oxygen and Air Pressure

Answer 19

Oxygen is supplied in the spacecraft, 80% is nitrogen and 20% is oxygen. The crew only wear spacesuits when outside of the spacecraft.

Question 20

Waste Management

Answer 20

The carbon dioxide that is exhaled must be removed from the spacecraft. The garbage that is produced is stored until landing. The toilets are designed to collect liquid and solid in a weightless environment, liquid is recycled and waste is compressed and stored.

Question 21

Food and Drink

Answer 21

Most food is freeze-dried, and water is added. Food must be quick to open and serve. Drinking is done with straws or zero-gravity cups.

Question 22

What must be conserved?

Answer 22

Air and water.