Mitosis, Exchange Surfaces and Lungs

Question 1

What is Mitosis?

Answer 1

type of cell division resulting in genetically identical diploid cells.

Question 2

What is the purpose of mitosis?

Answer 2

repair, growth and development of tissues in multicellular organisms
asexual reproduction

Question 3

What type of reproduction is mitosis, and what is its version in bacteria?

Answer 3

Asexual reproduction, binary fission

Question 4

What is the order of stages in cell division?

Answer 4

G1, S, G2, Mitosis, Cytokinesis, G0

Question 5

What does the G stand for in cell division?

Answer 5

Growth

Question 6

What does the S stand for in cell division?

Answer 6

Synthesis

Question 7

What happens in the G1 phase of cell division?

Answer 7

Subcellular structures (eg mitochondria) duplicate

Question 8

What happens in the S phase of cell division?

Answer 8

DNA replicates. now two copies of each chromosone

Question 9

What happens in the G2 phase of cell division?

Answer 9

DNA is checked for errors during replication. Enzymes are used to fix the mistakes.

Question 10

What happens in mitosis?

Answer 10

The chromosones move to opposite poles of the cell and two nuclei form.

Question 11

What happens in the G0 phase of cell division?

Answer 11

Temporary cell resting. Some cells will never divide again, eg, nerve cells

Question 12

How many chromosomes and pairs in a human adult cell?

Answer 12

46 chromosomes

23 pairs

Question 13

How many chromosomes and pairs in a sperm or egg cell?

Answer 13

23

Question 14

What happens in the prophase?

Answer 14

1) Chromosomes formed of 2 sister chromatiPs
2) nuclear membrane disaPPears
3) SPindle fiPres form

Question 15

What happens in the metaphase?

Answer 15

1) ChroMosoMes line up aloMg the equator

2) SpiMdle fibres attach to the ChroMosoMes

Question 16

What happens in the anaphase?

Answer 16

1) Sister chromatids pulled apart towards poles

Question 17

What happens in the telophase?

Answer 17

1)Nuclear membrane reform, creaTing Two nuclei

Question 18

What happens in cytokinesis?

Answer 18

1)cytoplasm+cell membrane divide, leaving two diploid daughter cells

Question 19

In which stage of cell division does the cytoplasm and cell membrane divide?

Answer 19

Cytokinesis

Question 20

In which stage of cell division does the nuclear membrane reform?

Answer 20

Telophase

Question 21

In which stage of cell division do the chromatids line up along the equator?

Answer 21

Metaphase

Question 22

In which stage of cell division do the spindle fibres form?

Answer 22

prophase

Question 23

In which stage of cell division do the nuclear membranes disappear?

Answer 23

prophase

Question 24

In which stage of cell division are the sister chromatids pulled towards the poles?

Answer 24

anaphase

Question 25

Where do the spindle fibres attach to the chromosomes?

Answer 25

At the centromere

Question 26

What are the spindle fibres made of?

Answer 26

Centriole

Question 27

What does diploid mean?

Answer 27

Two copies of a chromosome

Question 28

What are the disadvantages of mitosis?

Answer 28

Can cause cancer if g2 fails, not all cells can

Question 29

What is the equation you need to do to work out whether simple diffusion is enough for an organism to respirate?

Answer 29

Surface area to volume ratio

Question 30

Do large multicellular organisms have a small or large SA:V?

Answer 30

Small

Question 31

Do small single cell organisms have a small or large SA:V?

Answer 31

Large

Question 32

Why do large organisms require an exchange surface?

Answer 32

there'll be layers of cells between the center and environment- products of respiration will be used up before they reach the surface

Question 33

What are the features of an exchange surface? (4)

Answer 33

- large SA increases exchange site - Thin membrane decreases diffusion distance -a way to transport substances to/from exchange site -steep conc gradient

Question 34

How does inhalation take place?

Answer 34

- diaphragm contracts and flattens/moves down - intercostal muscles contract - ribs move in and out - chest volume increases - pressure decreases, air rushes in

Question 35

How does exhalation take place?

Answer 35

diaphragm relaxes and moves up - intercostal muscles relax - ribs move down and in - volume inside chest decreases - air rushes out

Question 36

How are small intestines adapted to be a good exchange surface?

Answer 36

- good blood supply - one cell thick wall - large SA- villi/microvilli

Question 37

How are lungs adapted to be a good exchange surface?

Answer 37

- alveoli wall is very thin - capillaries surrounding alveoli ensuring a good blood supply as oxygen is constantly moved round away from the lungs maintaining a steep concentration gradient - well ventilated - surfaces

Question 38

How are fish gills adapted to be a good exchange surface?

Answer 38

- Good blood supply assists with quick absorption - gill filaments have large SA - thin walls for short diffusion distance

Question 39

How are root hair cells adapted to be a good exchange surface?

Answer 39

-projections increase SA -constant water flow -thin walls for short diffusion distance

Question 40

How are leaves adapted to be a good exchange surface?

Answer 40

- stomata- small holes for movement of gases - flattened shape, large SA - thin walls for short diffusion distance

Question 41

What do plant leaves exchange

Answer 41

Co2 and oxygen

Question 42

What do root hair cells exchange?

Answer 42

Water and mineral ions

Question 43

What type of blood vessel is found in villi?

Answer 43

Capillaries

Question 44

What type of blood vessel surrounds alveoli?

Answer 44

Capillaries

Question 45

What is special about the way the intercostal muscles interact?

Answer 45

They act antagonistically.

Question 46

Which intercostal muscle is stronger?

Answer 46

External

Question 47

What links active transport and diffusion?

Answer 47

transport of solutes