Cell division

Question 1

What is a gene?

Answer 1

A short section of DNA that codes for a protein/controls a characteristic

Question 2

What are chromosomes?

Answer 2

Structures in the nucleus that carry genes

Question 3

How many chromosomes are in one human body cell?

Answer 3

46

Question 4

Chromosomes are arranged in ___ pairs in a human body cell.

Answer 4

23

Question 5

How many percent of your chromosomes have you inherited from your father?

Answer 5

50%

Question 6

Briefly describe the cell cycle.

Answer 6

Cell content (including DNA) is replicated, mitosis occurs to make two genetically identical cells

Question 7

Define ‘mitosis’.

Answer 7

Cell division that produces two genetically identical daughter cells

Question 8

Which type of reproduction is based only on mitosis?

Answer 8

Asexual

Question 9

State three key importances of mitosis.

Answer 9

Growth, repair, asexual reproduction

Question 10

Briefly describe the first stage in the cell cycle.

Answer 10

Cell size increase, DNA and organelle replication

Question 11

Briefly describe the second stage (mitosis) in the cell cycle.

Answer 11

Nucleus divides - One set of chromosomes is pulled to each end of the dividing cell

Question 12

Briefly describe the third stage in the cell cycle.

Answer 12

Cytoplasm and cell membrane divides into two daughter cells

Question 13

What has to happen to the cell before mitosis to ensure we can two genetically identical daughter cells?

Answer 13

DNA and organelles must replicate before division

Question 14

Define ‘differentiation’.

Answer 14

The process where a cell becomes specialised/adapted to perform specific functions

Question 15

Define ‘stem cell’.

Answer 15

Undifferentiated cell with the potential to become specialised

Question 16

Define ‘adult stem cells’.

Answer 16

Stem cells that can only differentiate into a specific type of cell

Question 17

Where does differentiation of stem cells occur in humans?

Answer 17

Bone marrow

Question 18

Where does differentiation occur in plants?

Answer 18

Meristem/Root tip/Shoot tip

Question 19

Define ‘cloning’.

Answer 19

Production of identical offspring by asexual reproduction/mitosis

Question 20

By which cell division type does cloning occur?

Answer 20

Mitosis

Question 21

Define ‘zygote’.

Answer 21

The single new cell formed right after fusion of gametes(sperm and egg)

Question 22

Define ‘embryo’.

Answer 22

A ball of cells made from mitosis of zygote

Question 23

Define ‘embryonic stem cells’.

Answer 23

Stem cells from an early embryo that can differentiate into all cell types

Question 24

Where do you get adult stem cells in animals?

Answer 24

Brain, bone marrow, blood vessels, skeletal muscle, skin, teeth, heart, gut, liver

Question 25

Suggest two diseases that may be treated with stem cell treatment.

Answer 25

Paralysis, diabetes, blindness

Question 26

Briefly describe how we can use stem cells to treat someone with type 1 diabetes.

Answer 26

Induce embryonic stem cells to produce healthy pancreas cells to make enough insulin

Question 27

Where do you get stem cells in plants?

Answer 27

Meristem/Root tip/Shoot tip

Question 28

Why is the ability to clone plants quickly a benefit?

Answer 28

Produce large numbers of rare plants reliably and safely to stop their extinction and for research, agriculture advances

Question 29

State one medical/scientific benefit of therapeutic cloning.

Answer 29

No rejection problem

Question 30

State one risk or concern people may have about using stem cells.

Answer 30

Concerns: Unethical to use aborted embryos; difficult and expensive project; cancer concern; Risk: viral infection/transmission