6 Kingdoms of Life Part 2:Plants and Animals

Asexual vs. Sexual• Recall that all organisms reproduce either

sexually or asexually– Sexual- there is a combining of genes from 2 parents but NOT always with egg and sperm (meiosis followed by fertilization)– Asexual- the offspring are reproduced by copying the DNA of one parent (binary fission or budding)

Plant Kingdom• All plants are multicellular• Their cells have a cell

wall--cellulose • Autotrophs-make own

carbs for energy through photosynthesis

• Can reproduce sexually, asexually, or both

What Plants Need to Survive…

• Sunlight• Water • Vitamins/Minerals• Gas Exchange

(O2 and CO2)

• A method of transport to move water and other

materials to all parts of plant.

What Plants Need to Survive…• Phototropism- a method of homeostasis

and response to a light stimulus in which the direction of growth is determined by the direction of the light source.

• Can plants move?

General Life Cycle Plants• Two alternating phases:

1) Diploid Phase—2 copies of all genes (Sporophyte)

-Sporophyte makes spores by meiosis.-Spores develop into gametophyte form

of plant.

2) Haploid Phase– 1 copy of all genes (Gametophyte)

-Gametophyte produces male and female gametes by mitosis—makes more haploid cells.

-Gametes eventually join to form sporophyte.

Alternating Phases: Plant Life Cycle

Example of a Plant Life Cycle

Evolutionary Trends and Plants…

• Ancestors of 1st plants were multicellular green algae.

• Plants have evolved specific adaptations to help them survive in a variety of different climates.

• There are four major groups of plants which are separated by three distinct features:1. Water conducting tissue (vascular).2. Seeds3. Flowers

4 Major Groups of Plants

Green Algae Ancestor

1. Plant groups by vascular tissue1. Bryophytes (Moss)

2. Pteridophytes (Ferns)

3. Gymnosperms (Cone bearing plants)

4. Angiosperms (Flowering plants)VASCULAR TISSUE

NO VASCULARTISSUE

Vascular Plants•Vascular- internal transportation system

• Xylem – water carrying tubes • Phloem – sugar carrying tissues • Enabled plants to evolve into larger specimens. • Pteridophytes (Ferns), angiosperms and gymnosperms are all vascular

Nonvascular Plants • Simplest of all land dwelling plants 

•Bryophytes •Nonvascular (no “veins”)-lack an internal means for water transportation•Obtain/transfer water by osmosis•Grow moist, shaded areas•No true roots, leaves, stems•Rhizoids anchor plant to ground

2. Plants Groups by Seeding

1. Bryophytes (Moss)2. Pteridophytes (Ferns)

3. Gymnosperms (Cone bearing plants)• Form seeds in “cones.”

4. Angiosperms (Flowering plants)• Form seeds inside of “flowers.”

SEED PLANTS

NO SEEDS

Seed Plants• Seed plants do not require water for

reproduction like mosses so can live in most environments

• Seed plants produce “pollen” which is the male gamete and ovaries (ovules) which are female

• Pollen is extremely small and light and is easily carried by wind or small animals

Seeds• Plant gametes: Egg and sperm (pollen) of plant join

together to form seed• Seeds are embryos of seed plants encased in a

protective coating and surrounded by a food supply.

Bryophytes

• Do not produce seeds, but have egg and sperm only which must meet to form a new bryophyte.•Require water for fertilization to transport gametes

Pteridophytes (Ferns)• No seeds—have egg and

sperm join and produce spores

• Contain vascular tissue• 1st true land plants

•Gymnosperms– Means “naked seed”– Oldest vascular, seed-

producing plants

Gymnosperms• Seeds are exposed • Most common are

“conifers” (spruce, firs, pines, etc.).

• Most have needles instead of leaves.

• Most conifers are “evergreens” meaning they keep their needles (leaves) year round.

• Angiosperms - Means “enclosed

seed”– Flowering – Most common of all

land plants

3. Plant groups by flowers

1. Bryophytes (Moss)2. Pteridophytes (Ferns)

3. Gymnosperms (Cone bearing plants)• Form seeds in “cones.”

4. Angiosperms (Flowering plants)• Form seeds inside of “flowers.”

FLOWERS

NO FLOWERS

Flowers• Angiosperms are the only flowering

plants• Flowers attract animals to support

pollination (very efficient)• Seeds develop inside ovary within a

“flower”• After “fertilization” seed within flower

develops into “fruit”• Angiosperms are typically

classified in two groups:1. Monocots2. Dicots

Life Spans of Angiosperms

• Annuals- survive one season

• Biennials- take 2 years to complete life cycle

• Perennials- live many years

Animalia Kingdom•All animals are:

—Multicellular: cells lacking a cell wall

—Heterotrophs

—Capable of movement at some point in their lives.

—95% of all animals are invertebrates

Criteria for Animal Classification • Skeletal Characteristics

– Invertebrates -have a hard external skeleton made of chitin known as an exoskeleton

– Vertebrates have a hard internal skeleton made of bone or cartilage

• Kingdom Phylum

ClassOrder Family

Genus

SpeciesMajor phylums of animals are…

• Nine major phyla of animals:1. Poriferans (sponges)2. Cnidarians (jellyfish)3. Flatworms (tapeworm)4. Roundworms (heartworm)5. Annelids (earthworm)6. Mollusks (clam)7. Arthropod (grasshopper)8. Echinoderm (starfish)9. Chordate (human)

Invertebrates

More complex

• Porifera– Sponges– Invertebrates– Sponges are filter feeders and depend on the movement of water to

obtain nutrients/oxygen– Digestion is intracellular –no stomach– Reproduce asexually by budding or sexually through egg and sperm

• Cnidarians– Jellyfish, corals, and other stingers. . . Their

stinger is called a nematocyst– Invertebrates– Belizes coral reef

• Mollusks– Octopi, squid, clams, oysters, snails,

slugs– Invertebrates– Reproduce sexually

– Cool Octopus video

• Platyhelminthes (flat worms)– Tapeworms & Liver Fluke & Planaria– Hermaphrodites-fertilize their own sex cells

internally then zygotes are released into water to hatch

– Invertebrates– Sexual or asexual reproduction

Human liver fluke

• Nematodes (roundworms)– Heartworms, hookworm, pinworms– One of the most diverse animal

phyla– Many are parasites– Sexual reproduction

• Annelids (segmented worms)– Worms & leeches– Invertebrates– Worms mating

• Echinoderms– Starfish, sea urchins, sea cucumbers– They have a hard exoskeleton under their

skin– Invertebrates

• Arthropods– Shell fish, arachnids & BUGS!– Invertebrates—have exoskeleton– Reproduce sexually

• Chordates– All other animals that have a backbone

of some form– Vertebrates

Trends in Animal Evolution•Complex animals tend to have…

1.Specialized cells and organs2.Bilateral body symmetry3.A definite head with sensory

organs (cephalization)4.A body cavity5.Complex embryonic

development

Trend #1: Specialized Cells and Organs

• The more complex the animal, the more “specialized” its cells become.

• Cells Tissues Organs Organ system.

• Some animals have no organs!

Trend #2: Body Symmetry • With the exception to sponges,

every animal exhibits one of two types of body symmetry:1. Radial symmetry2. Bilateral symmetry

Radial Symmetry• Imaginary plane can pass through

a central axis in any direction

Bilateral Symmetry• Single plane can divide the body into two

equal halves• Animals with bilateral symmetry have a

right and left side and usually have segmented bodies

Trend #3: Cephalization• Animals with bilateral symmetry have a

definite head• Cephalization is the concentration of

sense organs and nerve cells in the anterior end (front end) of the body

• Animals with this trait tend to respond in more complex ways to their environment

Trend #4: Body Cavity Formation

• Most animals have a body cavity in which all major organs are attached. This area is called a coelom

• Provides room for organs to grow and expand

• Less complex animals do not have this area. They are called acoelomates

During gastrulation, cells begin to differentiate (specialize).

Trend #5 Embryo Development

Worms, mollusks, arthropods, etc.

Chordates and Echinoderms

Protostomes vs. Deuterostomes

• In protostomes (worms, mollusks, and arthropods), blastopore develops into mouth.

• In deuterostomes (echinoderms and chordates), blastopore develops into anus.

• Three layers of embryonic cells (germ layers):1. Endoderm – Develops into digestive and respiratory

tracts.2. Mesoderm – Develops into muscles, heart, sex organs,

and kidneys.3. Ectoderm – Develops into brain, sense organs, and skin.