🌱Plants BIO153

How did leaves allow plants to live on land?

they provide a surface area to acquire sunlight and CO2 from above the ground

How did roots allow plants to live on land?

they anchor plants to the ground and absorb water and nutrients from the soil

What does the vascular system do?

transports water and minerals throughout plant body

What are the primary tissues of the vascular system?

xylem and phloem

What is the benefit of being tall and elevated for plants?

taller plants have better exposure to light and more reproductive success

Xylem

transports water and minerals from roots to leaves

Phloem

transports sugars from storage/production sites to other parts of the plant body

Cuticle

waxy polymer covering plant body for protection against desiccation

Stomata

pores on outer layer of leaves and stems allowing for O2 and CO2 exchange, closes in dry conditions to preserve water

What did mosses develop to survive on land?

anti-desiccation mechanisms

What did ferns develop to survive on land?

vascular system and tissue specialization

What did gymnosperms develop to survive on land?

pollen, ovule, and seed

What did angiosperms develop to survive on land?

flowers and fruit

What is the dominant life cycle in mosses?

gametophyte

What is the dominant life cycle in ferns?

sporophyte

What is the dominant life cycle in gymnosperms?

sporophyte

What is the dominant life cycle in angiosperms?

sporophyte

Sporophyll

specialized leaves of vascular plants which have been modified to produce spores

Sporangium

structures located on the sporophyll that produce and contain spores

How are moss attached to the ground?

by rhizoids, which do not transport water unlike real roots

What is distinctive about gymnosperms?

they form pollen and seeds but not flowers

What does “micro” refer to?

male reproductive structure

What does “mega” refer to?

female reproductive structure

What do microspores grow into?

microspores grow into the male gametophyte and produce sperm (pollen)

What do megaspores grow into?

megaspores grow into female gametophyte and produce eggs

How many sets of chromosomes does a sporangium have?

It is a diploid cell with two sets of chromosomes (2n)

How many sets of chromosomes do the spores produced by sporangium have?

They are haploid cells with one set of chromosomes (n)

What does sporangium do?

it produces spores via meiosis

What is the ovule made up of?

integument + megasporangium + megaspore

What does the ovule develop into?

the ovule develops into a seed after pollination

What does the integument do?

it becomes the seed coat after fertilization

How does pollination lead to fertilization?

The pollen grain attaches to the ovule through pollination and the pollen tube delivers sperm to egg, fertilizing it and forming a zygote. The zygote forms into an embryo which will later form a sporophyte.

What is the difference between the ovule in gymnosperms and in angiosperms?

In gymnosperms, the ovule is exposed to the environment. In angiosperms, the ovule is encased inside the ovary.

What happens to the ovule in angiosperms upon pollination?

The ovule develops into a seed and the ovary develops into a fruit.

Septal

base of the flower, encloses the flower before it opens

Petal

brightly colored and attracts pollinators

Stamen

male reproductive organ of flowers

Anther

part of the stamen, contains microsporangia to produce pollens

Filament

part of the stamen, supportive structure of the anther

Carpal

female reproductive organ made up of the stigma, style and ovary

Stigma

sticky tip of the carpal that captures pollens

Style

connects stigma to ovary

Ovary

the base of the carpal that contains the ovules

What occurs to the ovule and ovary after pollination?

The ovule develops into a seed and the ovary develops into a fruit.

Where does the pollen land during pollination in angiosperms?

on the stigma of the carpel

How is pollen produced?

The microsporangium in the anther produces microspores which develop into male gametophytes that eventually get packaged in pollen alongside sperm.

What is the pollen tube and how is it formed?

The pollen tube delivers sperm to the ovule and begins to grow after pollen is delivered to the stigma.

Simple fruit

derived from a single carpel or several fused carpals (eg. peas)

Aggregate fruit

derived from a single flower with a group of carpels forming a cluster (eg. raspberries)

Multiple fruit

derived from a group of flowers clustered together, each segment developing from the carpal of one flower (eg. pineapple)

Accessory fruit

contains tissue from plant parts other than the ovary (eg. apples)

What is the first step of pollination?

The pollen grain attaches to the ovule and the pollen tube delivers sperm to egg, fertilizing it and forming a zygote

What happens after the zygote is formed in pollination?

the zygote grows into the embryo which will later form a sporophyte

What is the symbiotic relationship between Rhizobium and plants?

Nodules develop in plant roots for Rhizobium to live inside, which provides anaerobic environment for bacteria to fix nitrogen.

What are some similarities between plants and algae?

-Photoautotrophic

-Alternation of generation

-Plastid DNA

-Cellulose cell walls

PGDC (photosynthesis, generation, DNA, cellulose)

What does moss have to protect against desiccation?

sporopollenin covering the spores

What do moss spores grow into?

protonema

What does the protonema do?

it produces buds which grow into full male or female gametophytes

Why is the moss life cycle dependent on water?

moss lack vascular tissue and thus all parts of a moss gametophyte need to directly absorb water from the environment

What do fern spores grow into?

a hermaphrodite gametophyte that produces both sperm and eggs

What supports the zygote while it develops into a sporophyte?

the gametophyte

What is contained within the seed?

the sporophyte embryo

Cones

scaly sporophylls produced by gymnosperms

What is distinctive about the gymnosperm life cycle?

They can reproduce without water since their pollen is dispersed by the wind

Sporocyte

a cell produced inside the sporangium which undergoes meiosis to produce haploid spores