1 Cell Biology - Cell Division Flashcards Preview

AQA Biology Paper 1 11-1A > 1 Cell Biology - Cell Division > Flashcards

Flashcards in 1 Cell Biology - Cell Division Deck (30)
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1

What is a gene?

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

2

What are chromosomes?

Structures in the nucleus that carry genes

3

How many chromosomes are in one human body cell?

46

4

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

23

5

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

50%

6

Briefly describe the cell cycle.

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

7

Define 'mitosis'.

Cell division that produces two genetically identical daughter cells

8

Which type of reproduction is based only on mitosis?

Asexual

9

State three key importances of mitosis.

Growth, repair, asexual reproduction

10

Briefly describe the first stage in the cell cycle.

Cell size increase, DNA and organelle replication

11

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

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

12

Briefly describe the third stage in the cell cycle.

Cytoplasm and cell membrane divides into two daughter cells

13

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

DNA and organelles must replicate before division

14

Define 'differentiation'.

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

15

Define 'stem cell'.

Undifferentiated cell with the potential to become specialised

16

Define 'adult stem cells'.

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

17

Where does differentiation of stem cells occur in humans?

Bone marrow

18

Where does differentiation occur in plants?

Meristem/Root tip/Shoot tip

19

Define 'cloning'.

Production of identical offspring by asexual reproduction/mitosis

20

By which cell division type does cloning occur?

Mitosis

21

Define 'zygote'.

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

22

Define 'embryo'.

A ball of cells made from mitosis of zygote

23

Define 'embryonic stem cells'.

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

24

Where do you get adult stem cells in animals?

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

25

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

Paralysis, diabetes, blindness

26

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

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

27

Where do you get stem cells in plants?

Meristem/Root tip/Shoot tip

28

Why is the ability to clone plants quickly a benefit?

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

29

State one medical/scientific benefit of therapeutic cloning.

No rejection problem

30

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

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