Chapter 4BCD Eukaryotic +Apoptosis+ stem cells

Question 1

In single-celled eukaryotic cells

Answer 1

use mitosis to reproduce asexually

Question 2

In multicellular eukaryotic cells

Answer 2

use mitosis for growth and repair

Question 3

In a nucleus

Answer 3

are 23 pairs of homologous chromosomes.
-Made of chromatins, a long strand of DNA wrapped around proteins called histones.

Question 4

Interphase (G1, S, and G2)

Answer 4

-Volume of Cytosol increases (G1/2)
-Proteins synthesised for DNA replication (G1)
-DNA is replicated. (S)
-Proteins are synthesised to prepare for mitosis (G2)

Question 5

In G1 Checkpoint

Answer 5

checks certain criteria to determine if it is ready to progress.
-Large enough
-Not Damaged
-Enough nutrients for mitosis
-Positive cues

Question 6

In G2 Checkpoint

Answer 6

it checks if the cell is ready for mitosis.
-Proper replication in the S phase
-Enough recourses for mitosis

Question 7

In M checkpoint

Answer 7

checks if all chromosomes are correctly attached to spindle fibres.

Question 7

Mitosis

Answer 7

Prophase, Metaphase, Anaphase, Telophase

Question 8

Telophase

Answer 8

The chromosomes decondense back into expanded chromatin. Nuclear membrane reforms around each nucleus.

Question 8

Prophase

Answer 8

The chromatin condenses, and the centrioles are separate from each other, forming spindle fibres.
-The nuclear membrane then breaks down as the centrioles move toward the poles of the cell.
-Chromosomes move towards the equator of the cell

Question 8

Metaphase

Answer 8

The chromosomes are lined along the equator of the cell, and the kinetochore at each chromosome’s centromere extends kinetochore fibres that attach to the spindle fibres.

Question 9

Anaphase

Answer 9

The spindle fibres shorten, pulling the chromatids away, to the opposite poles of the cell.

Question 10

Cytokinesis

Answer 10

A contractile ring forms and contracts the cell membrane, membrane vesicles then fuse it together, dividing the cell into 2.

Question 11

Necrosis

Answer 11

uncontrolled cell death that is unexpected.
-Such as external injury or trauma

Question 12

Internal environment

Answer 12

the fluid inside a cell in a multicellular organism, such as the red blood cells in our body.

Question 13

Apoptosis

Answer 13

is programmed cell death, carried out by an ordered sequence of events.
-Allows for removal of cells without spilling contents into the internal environment.
-Failure of this process can lead to cancer

Question 14

Purpose of Apoptosis

Answer 14

If the cell is damaged or defective
Apoptosis sculpts the body during fetal development

Question 15

Extrinsic Apoptosis process

Answer 15

-FasL binds to a receptor protein (FasR), which three FasR bind in total.
-This new FasR shape attracts two FADD
-This new shape draws together Procaspase 8
-Procaspase cuts its tip to create Caspase 8
-Caspase 8 binds to Procaspase 3, it then cuts its tip creating Caspase 3
-Caspase 3 cuts the cell cytoskeleton, the framework that holds the cell in shape

Question 15

Extrinsic Apoptosis

Answer 15

involves a pathway from outside a cell that secretes a death ligand (FasL).

Question 16

Intrinsic Apoptosis (Mitochondrial Pathway)

Answer 16

begins in the mitochondria and initiates a sequence of events that destroy the cell.

Question 17

Intrinsic Apoptosis process

Answer 17

-Cytochrome C escape the mitochondria and bind to Apaf1
-Apaf1 then binds to Procaspase 9
-Procaspase 9 splits itself to create Caspase 9
-Caspase 9 binds to Procaspase 3
-Procaspase 3 splits itself to create Caspase 3, to cut the cell cytoskeleton

Question 18

Blebbing

Answer 18

Little bubbles, or blebs, that contain organelles, form around the cell
-Chromatin in the nucleus condenses
-After the cytoskeleton is cut, the Cell starts to shrink.

Question 19

Apoptotic Bodies (Disconnected blebs)

Answer 19

break away from the cell.
-The nucleus and chromatin start to fragment

Question 20

phagocytosis

Answer 20

-Lysosomes in the Phagocytes digest the contents of the cell engulfed.
-Cell content does not enter the environment but stays inside the blebs and is digested within a phagocyte.

Question 21

stem cell

Answer 21

undifferentiated cell that through mitosis turns into specialized cells

Question 22

differentiation

Answer 22

the specialization of a cell for a function in the body, through regulation of expression in genes

Question 23

totipotent

Answer 23

a cell has the potential the differentiate into either an embryonic stem cell (any in-body cell) or extraembryonic cell (outside of body)
-greatest potency

Question 24

pluripotent

Answer 24

a cell can differentiate into an embryonic stem cell (any in-body cell) (semi-potent)

Question 25

multipotent

Answer 25

can only differentiate into different related cell types (semi-sepcific)

Question 25

oligapotent

Answer 25

can only differentiate into a few closely related cell types (very-specific)

Question 26

unipotent

Answer 26

can only differentiate into one cell type (exact specific)

Question 27

ectoderm

Answer 27

only skin, nervous system cells

Question 28

mesoderm

Answer 28

only muscles, blood, bone, urogenital cells

Question 29

endoderm

Answer 29

only lungs and gastrointestinal cells

Question 30

TPMOU

Answer 30

Toti, Pluri, Multi, Oligo, Uni = The PP Makes Orange Urine