Cells and Control

Question 1

What is a gene?

Answer 1

a section of DNA which determines a characteristic and codes for a protein.

Question 2

What are Chromosomes?

Answer 2

tightly coiled lengths of DNA containing many genes.

Question 3

How many pairs of chromosomes do humans have?

Answer 3

23 pairs

Question 4

When do Cells divide?

Answer 4

an organism grows
an organism becomes damaged and needs to produce new cells for repair
organisms like bacteria reproduce asexually

Question 5

What is the cell cycle?

Answer 5

A growing and dividing cell goes through a series of stages.

Question 6

What is the Cell Cycles first stage?

Answer 6

cell growth and then synthesis of DNA

Question 7

What is mitosis?

Answer 7

A type of cell division which produces daughter cells identical to the parent.

Question 8

What happens in the Interphase?

Answer 8

The DNA in chromosomes copies itself ready for mitosis.

Question 9

What happens in the prophase?

Answer 9

chromosomes and their copies condenses to become more visible. The membrane around the nucleus disappears.

Question 10

What happens in the metaphase?

Answer 10

Chromosomes and their copies line up in the middle of the cell.

Question 11

What happens in the Anaphase?

Answer 11

Chromosomes and their copies are pulled to different ends of the cell.

Question 12

What happens in the telophase?

Answer 12

New membranes form around the chromosomes at each end of the cell.

Question 13

What happens in the cytokines?

Answer 13

The cell membrane pinches in and eventually divides into two daughter cells.

Question 14

What are the stages of mitosis?

Answer 14

prophase, metaphase, anaphase and telophase.

Question 15

What happens when a cell becomes cancerous?

Answer 15

begins to grow and divide uncontrollably.

Question 16

What do a group of cancerous cells produce?

Answer 16

a tumour

Question 17

What are the two types of tumours?

Answer 17

Benign and Malignant

Question 18

What are the two main types of animal stem cells?

Answer 18

Embryonic
Adult

Question 19

What passes along nerve cells?

Answer 19

Electric impulses

Question 20

Where in the body does mitosis take place

Answer 20

Everywhere

Question 21

What are 2 uses of plant stem cells?

Answer 21

They can be used to produce clones of whole plants
They can be used to grow more rare plant species

Question 22

What are the steps of mitosis and cytokinesis?

Answer 22

DNA condense to form chromosomes
Chromosomes line up in the centre
Cell fibres separate two arms of chromosomes to opposite side of cell
Cytokinesis - the entire cell divides to form two identical daughter cells

Question 23

What do we call plant tissues that are continually growing?

Answer 23

Meristem tissue

Question 24

Why are reflexes so fast?

Answer 24

they are automatic that don’t require the brain

Question 25

How does a synapses transmit an electrical signal?

Answer 25

releases of chemicals

Question 26

What do we call cells produced by mitosis?

Answer 26

Daughter cells

Question 27

What is the role of a sperm cell?

Answer 27

to deliver genetic material to an egg cell and fertilise it

Question 28

When does cellular differentiation mostly occur?

Answer 28

during the development of the embryo and foetus

Question 29

What type of cells make up the nervous system?

Answer 29

Nerve cells

Question 30

What is the role of the motor neurone?

Answer 30

Transfers a signal from CNS to and effector

Question 31

What does differentiation mean?

Answer 31

cells become specialised

Question 32

How many pairs of chromosomes do human cells usually have?

Answer 32

23

Question 33

What is the central nervous system composed of?

Answer 33

Brain and spinal cord

Question 34

How many did ions are there when a cell divides by mitosis?

Answer 34

1 division

Question 35

What is the role of a receptor?

Answer 35

To detect the stimulus

Question 36

What are the two main features of stem cells?

Answer 36

They can divide by mitosis They can differentiate into different types of specialised cells

Question 37

What are 3 reasons multicellular organisms need new cells?

Answer 37

Growth Development Repair

Question 38

Are cells produced by mitosis identical or unique?

Answer 38

identical

Question 39

What is the role of a sensory neurone?

Answer 39

Transport a signal to the CNS

Question 40

What is the cell cycle?

Answer 40

the series of steps that take place as a cell grows

Question 41

What is a stem cell?

Answer 41

an undifferentiated cell

Question 42

What is the gap between never cells called?

Answer 42

a synapse

Question 43

What are 2 main types of effectors?

Answer 43

Muscles Glands

Question 44

What is a specialised cell?

Answer 44

a cell that is adapted to perform a particular function

Question 45

Where are embryonic cells found?

Answer 45

in the embryo

Question 46

Where are adult stem cells found in the body?

Answer 46

in bone marrow

Question 47

What is the role of a relay neurone

Answer 47

To transfer from a sensory neurone to a motor neurone

Question 48

What are 3 diseases that can the treated with stem cells?

Answer 48

Anaemia Paralysis Type 1 diabetes