Growth And Development

Question 1

Nucleus

Answer 1

Controls what the cell does
Contains genetic information
Has a membrane extending from it with ribosomes attached

Question 2

Cell membrane

Answer 2

Controls movement into and out of the cell

Question 3

Cell wall

Answer 3

Made of cellulose

Strengthens and supports cell

Question 4

Chloroplast

Answer 4

Contains chlorophyll- absorbs light energy to make glucose

Question 5

Ribosomes

Answer 5

Where protein synthesis occurs

Located in the cytoplasm

Question 6

What cells have no nucleus, mitochondria, chloroplasts or vacuole

Answer 6

Bacteria

Question 7

Why does bacterial DNA float in circular strands

Answer 7

Bacteria have no true nucleus

Question 8

What are two ways growth can be measured

Answer 8

Increase in height or mass

Question 9

What is it called when cells specialise

In animal cells

Answer 9

The cells differentiate

Question 10

How do plants grow

Answer 10

Cells elongate

Division occurs at the tip of plant roots and shoots (meristem)

Question 11

Why dont animal cells have cell walls

Answer 11

Diffusion happens between them

Question 12

Why do many plants never stop growing

Answer 12

They never lose the ability to differentiate

Question 13

What are the tips of roots and tips of shoots known as

Answer 13

Meristems

Question 14

What are advantages and disadvantages of using dry mass to calculate increase in growth

Answer 14

Most accurate method

Destructive, kills organism

Question 15

In the human foetus what grows first

Answer 15

Head and brain, to coordinate the growth of the rest of the body

Question 16

An embryo has differential growth

Why will it have a larger proportion of heart tissue

Answer 16

The circulation of blood is vital to growth and development of the embryo so is prioritised

Question 17

Cell division is mainly restricted to tips of roots and shoots

In a plant what do the cells specialise into?

Answer 17

Xylem, phloem and a variety of others

Question 18

What are stem cells

What do they have the ability to do

Answer 18

They are UNDIFFERENTIATED so can specialise into any type of cell, tissues and organs

Question 19

Why are stem cells found in the embryo less limited than adult stem cells

Answer 19

Embryonic stem cells can specialise into any type of cell

Adult stem cells can only specialise into a limited variety of cells eg. Blood or bone cells

Question 20

What are the potential uses of stem cells

Answer 20

Research- investigate how cell division goes wrong in diseases like cancer
Drug testing- test safety of new medicine
Transplants- replace damaged or diseased cell or grow organs for transplantation

Question 21

Scientists need large numbers of embryos for stem cell use

How are they currently obtained

Answer 21

From IVF treatment

Remaining embryos are used

Question 22

What are ethical conflicts about obtaining embryos for stem cell research

Answer 22

Embryos left over from IVF would be destroyed so stem cell research is a good use

Embryos have potential to become human beings so it is wrong to experiment with them

Question 23

Vacuole

Answer 23

Filled with cell sap

Helps support celk

Question 24

Where is DNA stored in plants

Answer 24

In plants however, DNA is stored in the nucleus