Cell Growth and Division

Question 1

2 reasons why cells can’t grow more and more?

Answer 1

1. volume of cell grows (l x h x w) and surface area only grows l x h, making it difficult over time for the membrane to assist in caring for the volume of the cell. 2. there would have to be a movement of more material across the membrane for bigger organelles, causing traffic jams.

Question 2

cell division?

Answer 2

momma cell divides into 2 daughter cells

Question 3

what must happen first in order for cell division to occur?

Answer 3

DNA must be replicated

Question 4

asexual reproduction?

Answer 4

producing genetically identical offspring from only 1 parent cell

Question 5

can asexual reproduction occur in multicellular organisms?

Answer 5

yes. even some plants are asexual reproducers (shoots on the tip of a plant)….binary fission, budding

Question 6

sexual reproduction?

Answer 6

2 separate parent cells create offspring with genetic information from each parent

Question 7

Can some single celled organisms reproduce using sexual reproduction?

Answer 7

yes.

Question 8

advantages of sexual reproduction?

Answer 8

genetic diversity

Question 9

advantages of asexual reproduction?

Answer 9

quick and easy

Question 10

disadvantages of sexual reproduction?

Answer 10

need to find a mate

Question 11

what plant reproduces both sexually and asexually?

Answer 11

strawberry. the strawberry fruit grows from sexual reproduction from seeds and pollen but the green leafy runners that grow off of the berry are a product of asexual.

Question 12

chromosomes? main function?

Answer 12

genetic information (DNA) bundled into packages. main role - to package all the information nicely so that it can remain organized during replication and so that it can hold a lot of information efficiently

Question 13

chromatin?

Answer 13

DNA tightly bound to and coiled around histones (protein)

Question 14

nucleosomes?

Answer 14

chromatin bound so tightly that it forms these beadlike structures that are thick and fibrous.

Question 15

what is the “x” like chromosome shape in textbooks of DNA replication suppose to represent?

Answer 15

duplicated chromosomes with supercoiled nucleosomes.

Question 16

what 3 things happen in a What cell cycle?

Answer 16

1. cell grows, 2. cell prepares for division, 3. cell divides,

Question 17

the eukaryote cell has 4 stages. what are they?

Answer 17

G1, S1, G2, and M

Question 18

interphase includes which 3 stages?

Answer 18

G1, S1 and G2

Question 19

What happens in G1? S1? G2?

Answer 19

G1 - cell growth, S1 - DNA replication, and G2 - where DNA and organelle reproduction are completed

Question 20

Is mitosis part of interphase?

Answer 20

no. Its part of the M phase - the phase where the cell actually divides (but the DNA and organelles have already been replicated). M phase - mitosis and cytokinesis.

Question 21

Which is the longest: G1, S1 or G2? Why?

Answer 21

S because this where DNA gets replicated and thats filled with detailed info

Question 22

Which takes longer; mitosis or interphase?

Answer 22

interphase….requires more time to replicate than to separate.

Question 23

centromere?

Answer 23

centromere- the center where 2 chromatids meet (sister chromatids). spindle fibers - the special skeletal fibers that help the cells divide.

Question 24

centrosome?

Answer 24

centrosome - an area just outside the nuclear envelope ( but in the nucleus) where the spindles and centrioles are at.

Question 25

centrioles?

Answer 25

centrioles - tiny paired structures in the centrosome that connect the spindles.

Question 26

spindle fibers?

Answer 26

spindle fibers - the special skeletal fibers that help the cells divide.

Question 27

prophase? what happens?

Answer 27

genetic material inside the nuclear envelope condense, the sister chromatids become visible, spindle fibers form, the centrioles start moving to the poles

Question 28

metaphase?

Answer 28

nuclear envelope is gone, chromatids (centromeres) line up (no separation of sister chromatids yet), centrioles reach the poles, spindle fibers attach the chromatids to the centrioles.

Question 29

anaphase?

Answer 29

sister chromatids detach!

Question 30

telophase?

Answer 30

2 new nuclear envelopes form around the condensed , separated chromatin. spindle fibers shrink. there’s a dent in the cell’s membrane.

Question 31

cytokinesis?

Answer 31

division of the cytoplasm to form to separate cells.