Plant reproduction and Plant tropisms

Question 1

1. a)

Answer 1

c

Question 2

1. b)

Answer 2

b

Question 3

1. c), role of pollen tube

Answer 3

The pollen tube transports the male gametes from the pollen grain to the ovule, allowing fertilisation to occur.

Question 4

1. d), calculate

Answer 4

control=600
Actinoymin=300

rate 1=600/3
rate 2=300//3

200-100=100

Question 5

2) maize seed germinated

Answer 5

Scientists need to check whether the root has emerged from the seed coat

Question 6

2 ii, antibiotic variables

Answer 6

1) Temperature
2)Light intensity

Question 7

explain the effect of conc

Answer 7

Increasing the concentration of salt solution lowers the water potential outside the seed, making it harder for the seed to absorb water, which is needed for germination

Question 8

c i plants grow grav

Answer 8

Roots show positive gravitropism, meaning they grow in the direction of gravity.

Stems show negative gravitropism, meaning they grow against the direction of gravity.

Question 9

c ii roots and stem light

Answer 9

Stems show positive phototropism, growing towards light to maximise photosynthesis.

Roots show negative phototropism, growing away from light, usually into the soil where they can absorb water and minerals.

Question 10

P Q S

Answer 10

P=Anther
Q=Petal
S=Stigma

Petals are small, dull, and not scented, as they do not need to attract insects.

Anthers are large and hang outside the flower to easily release pollen into the wind.

Stigmas are large, feathery, and also hang outside the flower to catch airborne pollen.

Question 11

natural method

Answer 11

Fragmentation

Question 12

artificial method

Answer 12

cuttings