Growth

Question 1

How do plant cells grow?

Answer 1

Absorbing water through their vacuole.

Question 2

What are the parts of the external structure of a dicotyledonous seed and their functions?

Answer 2

Testa - tough protective coat
Micropyle - tiny hole in tests which allows water into seed
Hilum - a scar where the seed was attached to the pod by a stalk
Swelling due to the radicle

Question 3

What is growth?

Answer 3

The permanent increase in an organism.

Question 4

How do multicellular organisms grow?

Answer 4

Cell division by mitosis.

Question 5

How do animals grow?

Answer 5

Producing extracellular material.

Question 6

What is germination?

Answer 6

The process by which the embryonic plant in a seed grows into a seedling.

Question 7

What happens after cells grow to their full size?

Answer 7

They differentiate to carry out specific tasks.

Question 8

Another name for stalk.

Answer 8

Funicle.

Question 9

The parameters that can be measured in plants and animals?

Answer 9

Height, length, dry mass, wet mass, number of organisms, number of leaves and the surface area of leaves.

Question 10

Describe the two distinct phases of growth in plants.

Answer 10

The initial growth after fertilisation which forms an embryo in the seed which remains dormant for a period of time and the growth which happens right after germination.

Question 11

What are the parts of the internal structure of a dicotyledonous seed?

Answer 11

Radicle
Plumule
Micropyle
Two cotyledons

Question 12

Explain in detail, the structure of a dicotyledonous seed.

Answer 12

In a dicotyledonous seed, the embryo contains the radicle and plumule which are both joined to two cotyledons which store food for the radicle and plumule to use during germination. The testa surrounds the radicle, plumule and cotyledons.

Question 13

Give a different name for the radicle and plumule.

Answer 13

Embryonic root and embryonic shoot respectively.

Question 14

What does the seed contain?

Answer 14

The embryo of the plant

Question 15

What are needed for a seed to germinate? Why?

Answer 15

Oxygen, water and suitable temperature. Water and suitable temperature are needed to activate the enzymes so that chemical reactions can occur and oxygen is needed to produce energy via aerobic respiration.

Question 16

What happens during germination?

Answer 16

Water is absorbed through the micropyle which swells the seed and activates enzymes to breakdown the food stored in the cotyledons. Starch is broken down into maltose and then glucose, protein is broken down into amino acids and lipid is broken down into fatty acids and glycerol. After being broken down they are then translocated to the radicle and plumule where they can now be used. The amino acids make new cells in the tips of the radicle and plumule so that growth can occur and the glycerol, fatty acids and glucose are all used in respiration to produce energy to ensure growth in the radicle and plumule and to make the cellulose cell wall of new cells.

Question 17

Which foods are stored in the cotyledons?

Answer 17

Protein, starch and lipids.

Question 18

What are meristems?

Answer 18

The immature cells with thin walls that can still actively divide and grow.