Biodiversity (Plants)

Question 1

What did plants evolve from

Answer 1

Green algae

Question 2

How many known plant species are there?

Answer 2

325,000 known plant species today; most live on land

Question 3

What are the closest relatives of plants

Answer 3

Green algae (photosynthetic protists) called charophytes

Question 4

Key traits of plants that also appear in some algae

Answer 4

• Plants and some algae are multicellular, eukaryotic, photosynthetic
  autotrophs
• Some algae, like plants, have cellulose in their cell walls and chloroplasts containing chlorophyll a and b

Question 5

Sporopollenin

Answer 5

• a polymer that charophytes have a coating of which prevents zygotes from drying out
• found in plant spore walls

Question 6

Why move to land?

Answer 6

• unfiltered sunlight
• more plentiful CO2,
• nutrient-rich soil
• Initially,morespace!

Question 7

Why not move to land?

Answer 7

• scarcity of water
• lack of structural support against gravity

Question 8

Four key traits appear in nearly all plants but are absent in the charophytes

Answer 8

1. Alternation of generations
2. Multicellular, Dependent Embryos
3. Walled spores produced in sporangia
4. Apical meristems

Question 9

Alternation of generations

Answer 9

life cycles alternate between two generations of multicellular organisms: gametophytes and sporophytes

Question 10

What does the multicellular haploid gametophyte produce

Answer 10

haploid gametes (sperm and eggs) by mitosis

Question 11

Spores develop into

Answer 11

gametophytes

Question 12

Fertilized eggs (zygotes) develop into

Answer 12

sporophytes

Question 13

The diploid embryo is retained and protected within the tissue of

Answer 13

the female gametophyte

Question 14

Nutrients are transferred from parent to embryo through

Answer 14

placental transfer cells

Question 15

Plants are called embryophytes because

Answer 15

of the dependency of the embryo on the parent

Question 16

The sporophyte produces spores in multicellular organs called

Answer 16

sporangia

Question 17

Spore walls contain sporopollenin, which makes them

Answer 17

resistant to harsh environments

Question 18

Apical meristems

Answer 18

Localized regions of cell division at the tips of roots and shoots

Question 19

These cells divide continuously, enabling

Answer 19

elongation of roots and shoots for better resource acquisition

Question 20

cuticle

Answer 20

a waxy covering of the epidermis that
reduces water loss

Question 21

stomata

Answer 21

pores that facilitate gas exchange between the outside air and internal plant tissues

Question 22

Early plants lacked …… making absorption of nutrients from the soil challenging

Answer 22

true roots (and leaves)

Question 23

420 million-year-old fossils suggest that symbiotic associations with fungi (mycorrhizae), may have

Answer 23

helped plants without roots to colonize land

Question 24

When did microorganisms colonize land

Answer 24

3.2 billion years ago

Question 25

Vascular plants

Answer 25

Plants with complex vascular tissue system

Question 26

Vascular tissue

Answer 26

cells joined into tubes for the transport of water and nutrients

Question 27

Seedless vascular plants

Answer 27

have an extensive vascular transport system, but do not produce seeds

Question 28

Non-vascular plants (bryophytes)

Answer 28

lack an extensive transport system

Question 29

What did tree roots break down

Answer 29

rocks, releasing chemicals that reacted with CO2

Question 30

What resulted from the subsequent drop in atmospheric CO2

Answer 30

Global cooling and widespread glaciation

Question 31

The majority of living plants are

Answer 31

seed plants— vascular plants that produce seeds

Question 32

Seed

Answer 32

an embryo packaged with a supply of nutrients inside a protective coat

Question 33

Seed plants can be divided into two groups

Answer 33

1. Gymnosperms 2. Angiosperms

Question 34

Gymnosperms

Answer 34

form a clade that produce seeds that are not enclosed in chambers (“naked seeds”)

Question 35

Angiosperms

Answer 35

form a clade that produce seeds that develop inside chambers that originate within flowers

Question 36

Nearly 90% of living plant species are

Answer 36

angiosperms

Question 37

Seeds can disperse over

Answer 37

long distances by wind or other means

Question 38

If a sperm fertilizes the egg of a seed plant

Answer 38

the zygote grows into a sporophyte embryo

Question 39

The ovule develops into a seed:

Answer 39

an embryo, with a food supply, packaged in a protective coat

Question 40

Both .... and .... provide protection from harsh conditions and facilitate dispersal

Answer 40

seeds / spores

Question 41

In addition to seeds, all seed plants have reduced

Answer 41

gametophytes, heterospory, ovules, and pollen

Question 42

These adaptations help plants cope with

Answer 42

droughtand exposure to ultraviolet (UV) radiation

Question 43

Water is not required for fertilization in

Answer 43

seed plants

Question 44

Characteristics found in living seed plants date back to

Answer 44

the late Devonian period (380 million years ago)

Question 45

A 360-million-year-old fossil from the genus ...... provides the earliest evidence of seed plants

Answer 45

Elkinsia

Question 46

The oldest gymnosperm fossils are about

Answer 46

305 million years old

Question 47

Gymnosperms replaced ............... in the drying climate of the late Carboniferous period

Answer 47

seedless vascular plants

Question 48

What helped gymnosperms thrive?

Answer 48

Seeds, pollen, and adaptations for drought tolerance

Question 49

The gymnosperms consist of four phyla

Answer 49

– Cycadophyta – Ginkgophyta – Gnetophyta – Coniferophyta

Question 50

Gymnosperms have “naked seeds” exposed on

Answer 50

sporophylls that usually form cones

Question 51

Most gymnosperms are cone- bearing plants called

Answer 51

conifers, such as pines, firs, and redwoods

Question 52

Angiosperms are seed plants with reproductive structures (key adaptations) called

Answer 52

flowers and fruits

Question 53

With more than .........., angiosperms are the most diverse and widespread plants

Answer 53

290,000 species (90% of all plants)

Question 54

All angiosperms belong to the phylum

Answer 54

Anthophyta

Question 55

Flower

Answer 55

an angiosperm structure specialized for sexual reproduction

Question 56

Some angiosperms are wind pollinated, particularly those that occur in

Answer 56

dense populations, such as grass

Question 57

Flowers are variable in

Answer 57

shape (symmetry), size, color, and odor

Question 58

Plant-pollinator interactions may have affected the

Answer 58

rate of new species formation

Question 59

Angiosperms have been historically divided into two groups

Answer 59

- Monocots (one cotyledon) - Dicots (two cotyledons)

Question 60

Eudicots (“true” dicots)

Answer 60

form a clade that includes most of the species once categorized as dicots