The cell cycle (summary)

Question 1

Binary Fission

Answer 1

A form of asexual reproduction (produce genetically identical cells without sex cells)

Question 2

Steps Of binary fission?

Answer 2

Dna replication, Elongation, Septum Forming, Cell division

Question 3

What happens in Dna replications step (BF)

Answer 3

circular dna chromones (plasmids) uncoiled and replicated.

Question 4

What happens in Elongation step of (BF)

Answer 4

Cell stretches, duplicated dna migrates to opp sides of (replicating) cell.

Question 5

What hapens when the septum forms i (BF)

Answer 5

(Cytokinesis) pinches inwards at center and a dividing wall formed (septum) and cytokinesis begins

Question 6

What happens during cell division step (BF)

Answer 6

A new cell wall+cell mebrane formed down to center of dividing cells (forms 2 identical cells)

Question 7

Interphase?

Answer 7

first step of euk cell cycle, involves cellular growth and duplication of chromosomes (DNA).

Question 8

What occurs in GAP1 and Gap 0

Answer 8

Gapp1- cell growth, volume of cytosol increases, proteins synthetized, for DNA replication, organelles replicated. eg liver cells
Gap 0- resting stage for cells either quiesent (can reenter cell cycle) or terminally differentiated (cells remain in G0 indefinitely eg nerve cells)

Question 9

what occurs in S, G2 phase

Answer 9

sytnthetis phase- dna replicated, one chromosome turn into 2 genetically identical sister chromatids held together by centromere.
G2- cell growth, prepare for mitosis, cytosol Volume increases, proteins required for mitosis synthesizing

Question 10

Mitosis?

Answer 10

involves ofrtamtion of 2 genetically identical nuclei and seperation of sister chromatids.

Question 11

Cytokinesis

Answer 11

final stage of euk cell cycle in which cytoplasm (all organelles) divide and the OG cell seperats into 2 idential daughter cells.

Question 12

What cells can underog mitosis

Answer 12

somatic cells(not sex cells)

Question 13

Cytokenisi Animal V Plant

Answer 13

Animal -Cleavage furrow develops pinching Pm into 2 cells.
Plant - cause of cell walls a cell plate is formed before seperating into 2 new cells

Question 14

apoptosis

Answer 14

programmed cell death (regulated)

Question 15

Purpouse (apoptossi

Answer 15

to scult body into final form
to remove damaged infected/cancerous cells

Question 16

Types of Tumors

Answer 16

Malignant, Benign

Question 17

Malignent tumor?

Answer 17

abnormal cells that have invaded nearby tissues these are cancerous

Question 18

benign tumor?

Answer 18

slow growing masses that aren’t spread to other tissues or organs.

Question 19

Necrosis

Answer 19

unregulated cell death causing cell to swell and burst releasing contents into nearby enviroment.

Question 20

Factors affecting apoptosis

Answer 20

mutation in genes, physical, chemical, biological factors

Question 21

Stem cell?

Answer 21

are undifferentiated (not yet specalised) cells with the potential to become anytype of cell in the body.

Question 22

Properties to be considered stem cells

Answer 22

unspeciaclised and capable of self renewal

Question 23

Totipotent

Answer 23

stem cells that can differentiate into any cell type, zygote can differentiate into any cell type required to produce a fetus

Question 24

Pluripotent

Answer 24

cells that can differentiate into multiple cell types. Embryonic stem cells can differentiate into 3 germ layers (MESO,ECTO,ENTO)

Question 25

Multipotent

Answer 25

cells that can differentiate into limited number of cells. stem cells in bone marrow differentiating into type s of cells (white,red,platelets)

Question 26

Morula

Answer 26

A zygote undergoes mitotic division to form a morula, morula continues to divide until consists of 16 cells, this then enters and embeds itself in the uteros lining.

Question 27

blastocyst

Answer 27

the morua continues to divide until it becomes a blastocysrt. a blastocyst contins inner mass of cells surrounded by an outter layer.

Question 28

what do the outer layer of the blastocyst form

Answer 28

placenta

Question 29

what do the inner layer of the blastocyst form

Answer 29

tissue of embryo

Question 30

3 germ layers rise in inner mss

Answer 30

ecto,meso,endoderm

Question 31

ectoderm?

Answer 31

forms skin hair nervous system, eyes

Question 32

mesoderm?

Answer 32

muscles cartilage, blood bones

Question 33

Endoderm?

Answer 33

lungs, digestive system bladder and other organs

Question 34

Gastrula?

Answer 34

after implantation into uterine wall, blastocyst divides further into gastrula

Question 35

diffusion

Answer 35

movement of molecules from a region of higher concentration to a region of lower concentration down the concentration gradient

Question 36

If metaphase doesnt occur what will happen to the embryo

Answer 36

chromosomes don’t align properly. causes errors in chromosome separation. lead to developmental issues, birth defects, or miscarriage in the embryo.

Question 37

Instrinsic V Extrinsic

Answer 37

intrinsic pathway triggered by internal cellular stress, while the extrinsic pathway is initiated by external signals binding to death receptors on the cell surface. both activate caspase enzymes

Question 38

Mitocondiris relashinship with chloroplast

Answer 38

Mitochondria and chloroplasts both have their own DNA and are involved in energy conversion—mitochondria in respiration and chloroplasts in photosynthesis.