Biology Chp 2

Question 1

What is a eukaryote?

Answer 1

A cell that contains a nucleus and other organelles that are surrounded by a thin membrane.

**CAN BE A SINGLE-CELLED OR MULTICELLULAR ORGANISIM

Question 2

What are stem cells?

Answer 2

Stem cells are unspecialized cells that do not have a function yet.
- find their purpose as the organism grows
- make up characteristics suited to their role
- CAN become anything
- can’t reverse after specializing

Question 3

Where is DNA found?

Answer 3

In the nucleus

Question 4

Describe what happens in prophase

Answer 4

Chromosomes coil, condense, and thicken enough to become visible.

Because DNA was copied in interphase, you see sister chromatids. They are held on by centromeres.

The nuclear membrane breaks down and disappears

Centrosomes head to two opposite sides of the cell and Spindle Fibers form from them.

Question 5

What happens in Cytokinesis?

Answer 5

The cell membrane begins to punch and the cell finally divides into two daughter cells!

Question 6

What are the 4 phases of mitosis?

Answer 6

Prophase, Metaphase, Anaphase and Telophase

Question 7

What is diffusion?

Answer 7

The movement of particles from an area of high concentration to a low concentration until all the particles are evenly distributed.

Question 8

What is the cell theory?

Answer 8

1. All living things are made up of one or more cells.
2. The cell is the simplest unit of life that carries out all processes.
3. All cells only come from other cells.

Question 9

Cytoplasm

Answer 9

jelly-like substance that fills the cell and surrounds other organelles. Protects organelles and provides nutrients.

Question 10

Name the two types of stem cells

Answer 10

1. Embryonic Stem cells
2. Adult Stem cells

Question 11

Cell Wall

Answer 11

A rigid frame around the cell that provides strength and protection. Only found in plant cells

Question 12

Cell Membrane

Answer 12

Double lipid layer that protects the cell and allows substances to move in/out.

Question 13

Describe an embryonic stem cell

Answer 13

Embryonic stem cells are found in the embryo and can be harvested from the umbilical cord.

Question 14

Why do checkpoints occur during interphase?

Answer 14

Checkpoints occur during interphase to stop cell division incase:
- there is not enough nutrients for cell growth
- the DNA in the nucleus has not been replicated
- the DNA is damaged

Question 15

What is osmosis?

Answer 15

The movement of water molecules across a semi-permeable membrane to even out concentration.

Question 16

What are the three phases in interphase and their function?

Answer 16

G1: A growth period where new organelles and proteins are made

Synthesis: Cell synthesizes a copy of the DNA to prepare for mitosis

G2: Continuing to prepare for mitosis

Question 17

Describe what happens in metaphase

Answer 17

Chromosomes (or sister chromatids) line up in the middle of the cell.

Spindle Fibers stretch out from the centrosomes to the centromeres of each chromosome.

Question 18

What is a prokaryote?

Answer 18

A cell that does not contain a nucleus or other membrane-bound organelles.

Question 19

Vacuoles/Vesicles:

Answer 19

Membrane-bound organelle that stores nutrients, waste, and other substances the cell uses.

Question 20

Nucleus

Answer 20

Control center of the cell that contains all of the cell’s DNA.

Question 21

What are the three stages of cell division?

Answer 21

1. Interphase
2. Mitosis
3. Cytokinesis

Question 22

Describe an adult stem cell

Answer 22

Adult stem cells can also specialize but are more limited in what they can become.

Found in TISSUES and ORGANS.

Role: maintain and repair the tissue where they are found.

Question 23

Describe what happens in telophase

Answer 23

The spindle fibers disappear

A nuclear membrane forms around the two daughter chromosomes

Cell now has 2 nuclei

Daughter chromosomes uncoil and stretch enough to become invisible again.

Question 24

Three reasons for cell division

Answer 24

1/ Growth
2/ Repair
3/ Reproduction

Question 25

Describe what happens in anaphase

Answer 25

Centromeres split apart forming two sets of chromatids.

Spindle Fibers pull the chromatids to the opposite sides of the cell.

The two sets of chromosomes are now referred to as daughter chromosomes.

Question 26

What is concentration?

Answer 26

the number of molecules of a substance in a given volume.

Can be high concentration or low concentration.

Question 27

Chloroplasts

Answer 27

Contains a green substance called chlorophyll. Chlorophyll uses energy from the sun to convert CO2 and H20 into sugar and oxygen. (Photosynthesis)

PLANT CELL ONLY

Question 28

How many pairs of chromosomes do Humans have?

Answer 28

23

Question 29

Differences between Plant and Animal cells.

Answer 29

1. Animal cells do not contain chlorophyll and chloroplasts BUT plant cells do.
2. Animal cells do not have a cell wall, plant cells do.
3. Animal cells store energy in carbohydrates or lipids and plant cells store them in the form of starch or oils.

Question 30

Lysosomes

Answer 30

Digestion area of the cell. Break down bacteria and also clean up.

Question 31

What are organelles?

Answer 31

“Organs” of a eukaryotic cell that perform specific functions.

Question 32

Golgi apparatus (or Golgi bodies)

Answer 32

receives proteins from the endoplasmic reticulum and packages those proteins for delivery throughout the cell.

Question 33

Full form of DNA

Answer 33

deoxy-ribo-nucleic-acid

Question 34

Mitochondria

Answer 34

The powerhouse of the cell! Supplies the cell with energy.

Question 35

Endoplasmic reticulum - what are the two kinds?

Answer 35

Organelle is made up of small tubes that carry materials throughout the cell.

ROUGH ER: Use small ribosomes to make proteins.

SMOOTH ER: Makes fats and oils and does not have ribosomes.