Exemplar 1A Practice

If all cells come from pre-existing cells, then...

• All cells in an organism must maintain homeostasis

• All cells in an organism must have a metabolism

• All cells in an organism must divide to make more cells

• All cells in an organism must have all of the same organelles

Answer explanation

If all cells come from other cells, then where do they come from in a multicellular organism?

They come from other cells dividing!

Select all parts of the cell theory

• All cells come from other (pre-existing) cells

• Cells are the basic unit of life

• All living things are made of cells

• Cells are found in the body

• All cells can be found in groups

I am a gel-like fluid that fills the cell, I hold/contain all other organelles within the cell, I help material move around the inside of the cell. What organelle am I?

• Cell wall

• Cytoplasm

• Chloroplast

• Cell membrane

• Mitochondria

Plant and animal cells both have vacuoles, but why are they LARGER in plant cells?

• Plants need more energy

• Plants need to store more food and water

• Plants need to make more protein

• Plants need to move more material out of their cells

Answer explanation

The vacuole is like your refrigerator! It stores food and water!

How do cells maintain homeostasis?

• They keep nutrients out of the cells

• They make their own food within the cell

• They keep the waste inside the cell

• They let water into AND out of the cell

Answer explanation

Remember: HOMEOSTASIS means keeping things stable! If something goes in, it must come out!

What would happen if a cell couldn't move food into the cell, move waste out of the cell, and exchange water?

• The cell would make more cells

• The cell would maintain homeostasis

• The cell would move someplace else

• The cell would die

Answer explanation

If a cell cannot maintain homeostasis, it dies.

Homeostasis is keeping the inside stable, so food must come in, waste must go out, and water must be able to go in and out.

Organize these options into the right categories

Groups:

(a) Made of cells

,

(b) NOT made of cells

• skin

• DNA

• apples

• atoms

• sand

• water

• flowers

• molecules

• sugar

• chlorophyll

• lungs

• rocks

What do both plants and animals NOT have in common

• Cell division

• Response to stimuli

• Elimination of waste

• Getting food from the environment

Answer explanation

Remember, plants DON'T eat! They make their own food through the process of photosynthesis! Animals DO eat.

Over time, scientific ideas are challenged and changed. What statement best supports this idea?

• Science does not need to be ONLY based on facts

• Science can change because it is open to new ideas as they are discovered

• Science is not accurate because it is constantly changing

• Science is based on facts so it should NEVER change

Answer explanation

Science is always changing, but that doesn't mean that it is wrong. It's being updated by new discoveries and theories.

There are many types of models in science. For example, you can have a picture of a cell (2D) or a model made from play-doh (3D).

What's better about having a 3D model?

• 2D doesn't show the main parts of the cell while 3D does

• 2D doesn't have the right number of organelles while 3D does

• 2D doesn't have the cytoplasm in constant motion while 3D does

• 2D isn't accurate because real cells are 3D