Pinophyta Life Cycle

Question 1

Pinophyta Reproduction

Step 1

Adult sporophyte creates

Pollen cone (male strobila)

Seed cone (female strobilla)

Answer 1

Step 2

Microsporocytes create many microspores via meiosis

Megasporocyte creates 4 megaspores via meiosis

Question 2

Pinophyta Reproduction

Step 3

Microspores develop pollen grains, Immature male gametophyte 4 cells and 2 air sacs

3 of 4 megaspores dies, 1 develops into mature female gametophyte

Answer 2

Step 4

Pollen grains get carried by the wind and stick to a pollen drop

Question 3

Pinophyta Reproduction

Step 5

Pollen is drawn in through micropyle

Answer 3

Step 6

Pollen germinates

2 cells create pollen tube which grow to megasporangium

1 cell divides into sterile cell and spermatageouns cell

Question 4

Pinophyta Reproduction

Step 7

Mature female gametophyte develops 2-6 archegonia, each with one egg

Answer 4

Step 8

Spermatagenous cell creates 2 spem cells

Mature gametophyte = 2 sperm cells and 1 pollen tube

Question 5

Pinophyta Reproduction

Step 9

Pollen tube contacts archegonium

Answer 5

Step 10

Sperm fertilization

Question 6

Pinophyta Reproduction

Step 11

Sporophyte zygote grows into embryo and suspends growth

Answer 6

Step 12

Sporophyte adult creates a seedcoat and wing for seed

Question 7

Pinophyta Reproduction

Step 13

Answer 7

Seed escapes and is dispersed by the wind