Unit 7 notes 1 and 2

Question 1

Why do cells want to be small?

Answer 1

• They want a big surface area to volume ratio
• It is easy to move things in and out of the cell across the cell membrane

Question 2

What happens when a cell becomes to large?

Answer 2

The cell divides into 2 cells
- These 2 cells are called daughter cells

Question 3

Define cell division

Answer 3

The process where a cell divides into 2 new cells

Question 4

define the Cell cycle

Answer 4

A cycle of cell growth and division
- Cell grows, prepares to divide, and then divides

Question 5

What are the 2 major parts of the cell cycle?

Answer 5

Interphase and Mitosis

Question 6

What are the steps of the Interphase?

Answer 6

1. G1
2. S phase
3. G2

Question 7

How much of their time do adult mammal cells spend in the Interphase

Answer 7

90%

Question 8

what happening during the G1 phase?

Answer 8

Cell grows and proteins are made

Question 9

What happens during the S phase?

Answer 9

Cell copies it’s chromosomes and DNA is made

Question 10

What happens during the G2 phase?

Answer 10

Cell prepares to divide

Question 11

What can control cell growth?

Answer 11

Growth factors: Special proteins that speed up or slow down the cell growth and division

Question 12

When would you want to increase cell growth?

Answer 12

• Healing a wound
• Embryonic growth (growing a baby)

Question 13

Define cancer

Answer 13

Uncontrolled cell division
- Caused by defects in the proteins

Question 14

Define carcinogen

Answer 14

Any environmental agent that causes cancer

Question 15

What are examples of carcinogens?

Answer 15

Radiation, Smoking, Tobacco

Question 16

What is a Genetic factor?

Answer 16

Genes you can inherit that could increase your risk of cancer

Question 17

How do cancer cells spread?

Answer 17

Cancer cells from masses the tissues called tumors, that block nutrients from getting to healthy cells

Question 18

Define metastasis

Answer 18

A process where cancer enter the circulatory system (blood) and spreads

Question 19

Benign tumors

Answer 19

Not cancerous, do not spread to other parts of the body

Question 20

Malignant tumor

Answer 20

Cancerous, hamrful tumors

Question 21

How can you body stop a cell from becoming cancerous?

Answer 21

During the cell cycle the cell goes thourgh checkpoints, these checkpoints stop unhealthy cells from entering Mitosis

Question 22

What do the check points check for during the interphase?

Answer 22

• Does the cell need to divide
• Is the cell large enough to divide
• Does the cell have enough resources to survive
• Is the DNA damaged
• Has the DNA been replicated properly

Question 23

What happens if a cell does not divide, but nothing is wrong with it?

Answer 23

G0 phase - A phase of the cell cycle where a cell carries out it’s normal cell functions but is not preparing to divide

Question 24

Define Apoptosis

Answer 24

A process of programmed cell death
- A cell with destroy itself if it does not pass a checkpoint during the interphase

Question 25

What type of chromosome is in prokaryote cells?

Answer 25

One circlular chromosome

Question 26

How is DNA stored in prokaryote cells?

Answer 26

floating in the cytoplasm

Question 27

What happens during binary fission?

Answer 27

The cell duplicates its DNA and the cell divides into 2 new cells

Question 28

What type of cells go through binary fission?

Answer 28

prokaryotic

Question 29

How is DNA stored in eukaryote cells?

Answer 29

Wrapped into chromatins and chromosomes

Question 30

Define chromatin

Answer 30

Long strands of DNA wrapped around proteins called histones - Chromatin wraps up into chromosomes

Question 31

define chromosomes

Answer 31

structures that are packages of DNA

Question 32

What are somatic cells?

Answer 32

body cells

Question 33

How many Somatic chromosomes do you have?

Answer 33

46 chromosomes or 23 pairs

Question 34

What are gametes?

Answer 34

sex cells

Question 35

How many gametes do you have?

Answer 35

23 chromosomes/no pairs

Question 36

Define sister chromatids

Answer 36

2 halves of the chromosome, each half is an exact copy of the other half due to DNA replication

Question 37

Define centromere

Answer 37

A structure that holds the 2 sister chromatids together

Question 38

What are the phases of mitosis?

Answer 38

Prophase, Metaphase, Anaphase, Telophase

Question 39

What happens during the prophase?

Answer 39

- Chromatin coils up into visible chromosomes (condenses) - Nuclear membrane begins to disappear - centrioles move to opposite sides of the cell - Spindle fibers begin to from

Question 40

Define centriole

Answer 40

Small circular structures that are attached to the spindle fibers

Question 41

Define spindle fibers

Answer 41

Threadlike structures that attach to the chromosomes

Question 42

What happens during the metaphase?

Answer 42

- spindle fibers attach to the centromeres of the chromosomes - chromosomes line up in the middle of the cell

Question 43

What happens during anaphase?

Answer 43

- Sister chromatids move towards opposite sides of the cell

Question 44

What happens during the Telophase

Answer 44

- Nuclear membrane reforms - chromosomes begin to unwind - 2 new cells start to form that are identical

Question 45

What happens during cytokinesis?

Answer 45

-cytoplasm divides - occurs after mitosis

Question 46

What happen during cytokinesis in animal cells?

Answer 46

-cell membrane is pulled in toward that center of the cell until is splits

Question 47

What is a cleavage furrow?

Answer 47

The crease that is created during cytokinesis in animal cells

Question 48

What happens during