Gymnosperms II

Question 1

Describe details about the Coniferophyta

Answer 1

the most numerous, most
widespread, and most ecologically important of the
gymnosperm phyla

Question 2

Pines are conifers with unique ___ and leaf
arrangement

Answer 2

leaves and leaf
arrangement

Question 3

After 2 years of growth,
pines produce needles
in bundles called
___

Answer 3

fascicles

Question 4

Each fascicle is actually
a ___ with a
___ meristem,
which may be
reactivated to an
___
meristem if needed!

Answer 4

shoot/branch, determinate, indeterminate

Question 5

The leaves of pines are adapted for ___
conditions

Answer 5

dry

Question 6

why are fascicles needles?

Answer 6

Reduced Surface Area, Thick Waxy Cuticle, Sunken Stomata, Compact Vascular Tissue, Longevity

Reduced Surface Area: Needles have a much smaller surface area than broad leaves, which minimizes water loss through evaporation (transpiration).
Thick Waxy Cuticle: Pine needles are covered with a thick, waxy coating called a cuticle, which acts as a barrier to prevent water loss.
Sunken Stomata: The stomata (tiny pores for gas exchange) in pine needles are sunken into pits, which reduces exposure to air and further limits water loss.
Compact Vascular Tissue: The veins (xylem and phloem) are tightly packed and protected, helping conserve water and efficiently transport nutrients even under dry conditions.
Longevity: Pine needles can live for several years, reducing the need to constantly regrow leaves—a benefit in nutrient-poor and dry soils

Question 7

Where do pines live?

Answer 7

arid areas, high altitudes

Question 8

Pine cuticles

Answer 8

Thick cuticle, thick-walled layers of hypodermis, sunken stomata

Question 9

pine retention of leaves

Answer 9

Leaves usually retained for 2-4 years (up to 45 years in Bristlecone pines!)

Question 10

are pine leave microphylls or metaphylls

Answer 10

Pine leaves are megaphylls

Megaphylls are leaves with a branched network of veins and are typical of most vascular plants, including ferns, gymnosperms (like pines), and flowering plants. They evolved from branching stems and have complex vascular tissues.

Question 11

Pine stems undergo ___

Answer 11

secondary growth

Question 12

pine Xylem consists only of
___ and phloem
consists only of ___

Answer 12

tracheids, sieve cells

Question 13

Conifer wood =

Answer 13

softwood

Question 14

pine Resin ducts can be found
in the ___ tissue or
___ tissue of stems
and leaves

Answer 14

ground, vascular

Question 15

Resin contains ___
compounds that deter
herbivores and pathogen

Answer 15

phenolic

Question 16

The microsporangia and megasporangia of pines
(and most conifers) are found in separate cones on the same tree. what is this called

Answer 16

monoecious

Question 17

where are male and female cones found in pines

Answer 17

Typically, male cones are on lower branches and female cones are on upper branches – encourages outcrossing

Question 18

pine The microsporangia are found on
___

Answer 18

microsporangiate cones (staminate cones

Question 19

Each microsporangium contains ___ which undergo ___ to produce ___

Answer 19

any microspore mother cells (2n), meiosis, 4 haploid microspores

Question 20

Each microspore develops into a winged pollen grain that
contains 2 ___ , a ___ cell, and ___

Answer 20

prothallial cells, generative cell, a tube cell

Question 21

prothallial cells

Answer 21

remnants of gametophyte
tissue

Question 22

generative cell

Answer 22

will divide to make sperm

Question 23

tube cell

Answer 23

forms the pollen tube

Question 24

Ovulate (___) cones are larger
and more complex

Answer 24

megasporangiate

Question 25

The ovuliferous scales are not simple megasporophylls, but modified determinate branches called ___, where each scale has an ___ on the upper surface and a ___ bract below

Answer 25

seed-scale complexes, ovule, sterile

Question 26

Megaspore mother cell undergoes ___ to produce ___; ___ are degenerate

Answer 26

meiosis, 4 megaspores, 3

Question 27

The megaspore mother cell develops endosporically into the ____

Answer 27

megagametophyte,

Question 28

megagametophyte is surround by

Answer 28

sporophyte tissues (nucellus and integuments

Question 29

Eggs/ova form within archegonia at the ___

Answer 29

micropylar end

Question 30

Ovulate scales are far apart and exude ___

Answer 30

pollination drops

Question 31

Pollen grains settle on the scales, and pollination drops help carry the pollen grain through the ___ into contact with the ___

Answer 31

micropyle, nucellus

Question 32

After contacting the ___, pollen grain germinates to form a ___ – meiosis has not yet occurred in the megaspore mother cell

Answer 32

nucellus, pollen tube

Question 33

A month after pollination, ___ are produced, only one is functional and becomes the ___

Answer 33

four megaspores, megagametophyte

Question 34

15 months after pollination, ___ differentiate at the micropylar end of the megagametophyte – fertilization still hasn’t happened! Pollen tube is slowly digesting its way through the nucellus during this time

Answer 34

2 or 3 archegonia

Question 35

About a year after pollination, the ___ of the microgametophyte divides to give rise to a ____ and a ___ cell which further divides to produce ___ → now the microgametophyte is ___! (no antheridia in seed plants)

Answer 35

generative cell, sterile cell, spermatogenous, two sperm, mature

Question 36

Fertilization occurs about 15 months after pollination. The pollen tube finally reaches the ___ and discharges both sperm – one fertilizes the ___ and the other degenerates (but there may be ___ and ___)

Answer 36

archegonia, egg, 2-3 archegonia, polyembryony

Question 37

The conifer seed contains two different ___ generations and one ___ generation

Answer 37

sporophyte, gametophyte

Question 38

Gametophyte tissue serves as a ___ for the developing embryo

Answer 38

food reserve

Question 39

The seeds of pines are often shed during the ___ of the second year after pollination

Answer 39

fall