Biology Test 3

Question 1

Cells most often communicate with each other via _________.

Answer 1

Chemical signals

Question 2

For short distances, cells communicate using __________.

Answer 2

Local Regulators - Messenger molecules that only travel a short distance.

Question 3

For long distance, cells communicate using _____.

Answer 3

Homones

Question 4

Reception is:

Answer 4

The chemical reactions that result in a special protein (an “active protein”) Only cells with the right receptors respond to specific chemical signals Most receptors are plasma membrane proteins called a Ligand (fits like a lock-and-key into the receptor molecule)

Question 5

Transduction is:

Answer 5

A series of chemical reactions that result in a special protein. (an “active protein”)

Question 6

Response is:

Answer 6

The active protein triggers a cellular response

Question 7

A receptor that acts like a gate when the receptor changes shape:

Answer 7

A Ligand-gated ion channel - when a signal molecule binds as a ligand to the receptor, the gate allows specific ions through the channel in the receptor.

Question 8

Apoptosis is:

Answer 8

Programmed or controlled cell suicide. Components are chopped up and packaged into vesicles that are digested by scavenger cells. Prevents enzymes from leaking out of a dying cell and damaging neighboring cells.

Question 9

Steriods are:

Answer 9

Hydrophobic lipids. Sex hormones are steroids they send their signals by binding to “intracellular receptors”

Question 10

Cell division is:

Answer 10

When one cell becomes two. The most important part of cell division is copying the cell’s DNA

Question 11

A cell without DNA is a ____________

Answer 11

dead cell

Question 12

In a unicellular organism, a division of one cell ____________________________.

Answer 12

Reproduces the entire organism

Question 13

In multicellular organisms, division of one or more cells _______________________,

Answer 13

Does not reproduce the entire organism, just specific cell types.

Question 14

Cell division is used for:

Answer 14

1. Growth - body size increases 2. Development - going through stages, developing new organs, tissues, etc. 3. Repair - Tissue renewal

Question 15

Mitosis is:

Answer 15

Cell division that creates two “daughter” cells with exactly the same DNA as the “parent” cell

Question 16

Meiosis is:

Answer 16

Cell division that creates sperm cells and egg cells. The sperm cells created by meiosis does NOT have exactly the same DNA as one another, and neither do the egg cells created

Question 17

A genome is:

Answer 17

All the DNA in a cell constiutes the cells genome.

DNA is packed into chromosomes

Question 18

Somatic cells:

Answer 18

(nonreproductive cells) have TWO sets of chromosomes

Question 19

Gametes:

Answer 19

(Reproductive cells: sperm and eggs) have half as many chromosomes as somatic cells.

This is because half come from mom and half come from dad, then they come together and make a full set

Question 20

Mitosis only occurs in ____________, not ___________.

Answer 20

somatic cells, not Gametes

Question 21

Eukaryotic Cell division consists of ______ and ______

and what do they mean?

Answer 21

Mitosis, the division of the genetic mterial in the nucleus

Cytokinesis, the division of the cytoplasm

Question 22

What are the stages of the cell cycle?

Answer 22

• Interphase - Cell growth and copying of chromosomes in preparation for cell division. The DNA copies are joined together at the centromere. These are called sister cromatids.
• Prophase - The cromosome becomes visable under a microscope, and the miotic spindle builds.
• Metaphase - The nucleus is gone. The chromosomes line up in the middle of the cell. Microtubules start to attach themselves to the chromosomes.
• Anaphase - The miotic spindle pulls the sister chromotids apart, and they go to the opposite end of the cell.
• Telophase - The cell splits in two. Each new cell has two complete sets of chromosomes.

Question 23

What is the metaphase plate?

Answer 23

the chromosomes line up in the middle of the cell, along an imaginary line called the metaphase plate.

Question 24

two examples of gametes

three examples of somatic cells

Answer 24

eggs and sperm cells

skin, organ, blood… anything but eggs and sperm cells.

Question 25

How many complete sets of chromosomes do somatic cells have?

Answer 25

2

Question 26

During ______, the sister chromatids are pulled apart.

Answer 26

anaphase

Question 27

During _________ the two cells split apart.

Answer 27

telophase

Question 28

At the end of mitosis, the two new cells have _______________ of chromosomes

Answer 28

two full sets

Question 29

What phase is this?

Answer 29

Interphase

Question 30

What phase is this?

Answer 30

Prophase

Question 31

What phase is this?

Question 32

What phase is this?

Answer 32

Anaphase

Question 33

What phase is this?

Answer 33

Telophase

Question 34

______________ is the production of offspring that are exact compies of the parent.

Answer 34

Asexual Reproduction

Question 35

The formation of new organism by the protrusion of part of another organism, e.g. in corals and hydra.

Answer 35

Budding

Question 36

______________ - results in two identical daughter cells.

_____________- Results in variable egg and sperm cells.

Answer 36

Mitosis

Meiosis (Me)

Question 37

What is the