Transcript Biology 2201 Unit 2

Biology 2201
Unit 2- Biodiversity
Classifying Living Things
Ch. 6 – Plants & Animals
Ms. K. Morris – 2010-2011
Section 6.1
• Comparing Plants & Animals
–p. 164 - 168
Major Similarities:
• They are both multi-cellular, eukaryotes.
• Their sizes both range from microscopic to very
large.
Major Differences:
• How they obtain food.
• Movement
• Evolution
– Animals evolved in water, the only major groups found
on land are the insects, spiders and mollusks (snails).
– Plants evolved on land. Trees and grasses dominate
the land.
PLANTS
ANIMALS
Plants generally are rooted in one
place an do not move on their own
Most animals have the ability to
move fairly freely.
Plants contain chlorophyll and can
make their own food
Animals cannot make their own food
and are dependent on plants and
other animals for food.
Plants give off oxygen and take in
carbon dioxide given off by animals.
Animals give off carbon dioxide
which plants need to make food and
take in oxygen which they need to
breathe.
Plants cells have cell walls and
other structures differ from those of
animals.
Animal cells do not have cell walls
and have different structures than
plant cells
Plants have either no or very basic
ability to sense.
Animals have a much more highly
developed sensory and nervous
system.
Section 6.2
• Kingdom Plantae
–p. 169 - 181
Kingdom Plantae – Plants
Cell Type: all are eukaryotic.
Cell Wall: their cells all have a rigid (stiff) cell wall,
composed of cellulose.
Body Form: all are multicellular.
Nutrition: all are autotrophic and make their own food
using photosynthesis. They use sunlight as an energy
source and CO2 as a source of structural carbon. This
means that their energy and carbon come to them.
They do not have to move to acquire either.
Reproduction: Asexual & Sexual.
Locomotion: Non-motile. No movement.
Examples from the Kingdom Plantae:
1. Bryophytes
– Mosses, liverwarts, hornwarts
2. Ferns
– Ferns, whisk ferns, club mosses, horsetails
3. Gymnosperms
– Conifers, evergreens
4. Angiosperms
– Flowers, deciduous trees, peas
• Plants first appeared about 400 million years
ago!
• The ancestors of plants were algae.
Made up of three parts:
• Leaves- provide surface area for absorbing
sunlight.
• Stem- provides support for the leaves.
• Roots- anchors the plant and absorbs water
and nutrients from the soil.
Plants are classified based upon two major characteristics:
1. Whether they have vascular tissue or not.
• Vascular tissue - tissues used to efficiently transport food or
water through a plant.
• (present in Ferns, Gymnosperms and Angiosperms)
2. Their methods of reproduction. How plants carry out
sexual reproduction and how they develop into new
plants.
• whether they reproduction by using male sperm or male
pollen
• whether they develop from spores or seeds (spore
development is less advanced)
• what types of reproductive organs they have present
(flowers, cones, antheridia, ovule, etc.)
• gamete - a cell involved in sexual reproduction; male or female
sex cell such as sperm or eggs.
• spore - a single, specialized reproductive cell released from a
parent plant which can grow into a new plant. (produced by
the Bryophytes and the Ferns)
• seed - a multicellular structure containing several specialized
tissues and a partially developed, immature plant embryo. It
contains a food supply for the embryo and is protected by a
tough, outer coat. (produced by the Gymnosperms and
Angiosperms)
• pollen grain - the male gamete of a Gymnosperm or an
Angiosperm. It is a protective capsule which contains the male
gamete. It is transported by wind or carried on insects or
animals. (produced by the Gymnosperms and Angiosperms)
Two Major groups of plants:
VASCULAR – These plants have vascular tissue made up of:
– xylum (transports water) and
– phloem (transports nutrients)
• The xylum and phloem are comparable to our circulatory
system because it transports water, dissolved nutrients
and sugars to all parts of the plant. All plants are vascular
except mosses, liverworts and hornworts (Bryophytes).
NON-VASCULAR- These plants do not have vascular tissue.
They also lack or have poorly developed roots, stems and
leaves. They include: Mosses, Liverworts, Hornworts
(Bryophytes).
1. The Bryophytes - The primitive plants
• mosses, liverworts, hornworts ( see p. 170)
• Nonvascular - have no vascular tissue. No true roots , stems or
leaves ( true roots , stems and leaves have vascular tissue)
• They are restricted to a very tiny size; tallest mosses are just 8
cm tall. This is because without vascular tissue to speed up the
process, they must rely on diffusion to pass water and food
from cell to cell throughout their bodies. The diffusion process
is slow without the aid of vascular tissue so small size is a must.
• They still depend on the presence of water for sexual
reproduction to occur so they are restricted in their habitat to
places that are wet enough to provide the proper conditions for
this type of reproduction to occur.
• They still use sperm cells to reproduce. This is a primitive
process for land plants to use.
• Male Bryophyte plants release sperm cells during rainfall
or a heavy morning dew. The sperm must swim through
the water coating on the plants and soil surface to reach
female plants where they fertilize eggs.
• The eggs are contained in an open structure called an
archegonia. They are not protected well.
• Archegonia - the egg producing structures of a bryophyte
or fern.
• Antheridia - the sperm producing structures of a
bryophyte or a fern.
• The moss life cycle has two body forms , the sporophyte
and the gametophyte. (see diagram p. 170). They have a
dominant (meaning that it is larger, lives the longest and
is more complex) gametophyte generation.
• Gametophyte- is a plant that produces gametes, egg or
sperm.
• Non-vascular plants include mosses
(Bryophytes), hornworts, and liverworts.
These have no vascular tissue and most get
nutrients through diffusion and osmosis.
• These plants grow low to the ground.
• Non-vascular plants have no roots but they do
have structures called rhizoids which anchor
them to the ground.
• There are about 16 000 species of bryophytes.
They are common in moist, shaded areas.
• Examples of Bryophytes:
– Mosses, liverwarts, hornwarts
7/18/2015
15
2. The Ferns ( see p. 171)
• Ex. ferns, whisk ferns, club mosses, horsetails.
• They are vascular plants but still have primitive
reproduction - use sperm to fertilize eggs so they
are restricted to a moist habitat.
• They also use spores to reproduce instead of
seeds. Spore reproduction is more primitive than
using seeds.
• They have a dominant sporophyte generation.
(the dominant generation is the one that is
largest and lives longest).
• A sporophyte most times refers to a plant that
produces spores or pollen.
• Seedless vascular plants were the first
vascular plants to grow on Earth. These
include ferns and their relatives.
• These plants reproduce by spores. They are
able to grow tall and survive in a variety of
environments.
• Examples include whisk ferns, club mosses,
horsetails, and ferns.
• Seed- producing vascular plants are divided
into two main groups: gymnosperms (conifers
and relatives) and angiosperms (flowering
plants).
• The seeds contain the embryo and a food
supply. The embryo includes a root, a shoot,
and one or two seed leaves. The seeds allow
the plant to reproduce sexually without water.
It also provides protection during the dormant
period.
3. The Gymnosperms
- ex. Conifers and evergreens
• Name comes from the Greek word Gymnos which means
naked seed.
• This is because their seeds are not produced inside of fruits but
are exposed for fertilization on opened female cones.
• They are vascular plants.
• They are seed producing plants with no flowers.
• Their reproductive organs are cones.
• Male cones produce pollen.
• Female cones produce eggs.
• Theses plants are not dependant on water for reproduction.
• When fertilization is completed, theses plants produce seeds to
complete reproduction.
• They have a dominant sporophyte generation.
– Conifers or Evergreens
– A Tracheophyte (have vessels to move fluids)
– Coniferous plants
– Seeds are said to be naked and are born inside of
cones
– There are both male and female cones
– Include pines, firs, spruces, hemlocks
– Sometimes called “evergreens” because they do
not tend to lose all their needles at one time
– Leaves are needle-like or scale-like
• Gymnosperms have roots, stems and leaves. The
seeds are on the surface of the cones.
• These include pines, firs, yew, spruce, cedars, redwood,
and other large trees.
• They are able to reproduce without water and they
protect the stem from losing water by covering it with
bark.
• They have needle-like leaves with a thick, waxy
covering to reduce evaporation. The shape also
reduces water loss. The leaves are lost and replaced
year round. By keeping their leaves, they are able to
begin photosynthesis as soon as the weather becomes
warmer. They also do not need to use energy to grow
a complete set of new leaves.
Examples of Gymnosperms
• Black Spruce Cone
7/18/2015
/
Foliage
22
• Eastern White Pine Cone and Tree
7/18/2015
23
• Jack Pine Tree and Cone
7/18/2015
24
4. The Angiosperms – The flowering plants
- ex. roses, peas, magnolias, dandelions.
• They have flowers. The flowers house the reproductive structures.
• They are vascular plants.
• They produce pollen for reproduction so are not dependant on water
for reproduction.
• Female ovaries produce eggs.
• Male anthers produce pollen.
• Produce seeds for reproduction.
• Produce fruit to protect seeds.
• They have a dominant sporophyte generation.
–
–
–
–
–
–
–
These are the flowering plants
Also Tracheophytes
Dominant type of vegetation on the Earth today
Tend to have broad leaves
Leaves are usually lost all at one time (Fall)
Seeds are produced inside of fruit
Fruit are produced from flowers
• Angiosperms or flowering plants protect their seeds
within fruits.
• More than 75% of all plants are angiosperms. They
include trees, shrubs, herbs, grasses, vines and water
plants. They grow everywhere on land.
• There are two classes based on the number of seed
leaves or cotyledons. Monocots have one seed leaf
and include grasses, lilies, orchids, and irises. Dicots
have two seed leaves and include roses, peas, cacti,
daisies, and maple trees. Refer to the table on page
175 for more differences.
• The main reason for the diversity of angiosperms is the
flower which contains the reproductive organs for
these plants.
Examples of Angiosperms
• Bird-of-Paradise Flower
Variety of Fruit
7/18/2015
27
Why Angiosperms are the Most Diverse Plant Group
– See p. 175-179
• Angiosperms are found in more places and have
more species than any other plant group. This is
because they have evolved better reproductive
methods and adaptations that help reproduction.
• Pollination - the means by which the male pollen of
a plant gets to the female reproductive plant
structure.
• Flower - reproductive structures found in
Angiosperm plants. Flowers contain the
reproductive organs of the plant.
Angiosperms have:
1. Better protection of the sexual organs and gametes.
• Sexual organs are protected inside of the flower reproductive
structures. This offers more protection than the gymnosperms.
2. Better methods of pollination.
• The gymnosperms use only wind for pollination however pollination in
Angiosperms is by many methods. The methods used varies with the
species of angiosperm. Wind, insects, birds, bats and other animals take
part in pollination in angiosperms. Flowers attract insects and animals
by offering extra pollen and sugar - rich nectar as food. This is a
mutualistic relationship - both the animals and the plants benefit. When
the animals try to collect food, pollen is brushed onto their bodies the
male reproductive structures of the flower. When the animal visits
another flower, pollen on its body is brushed onto the top part of the
female reproductive organ.
• Adaptations to help pollination include flower scent, flower color and
even mimicry. Most flowers are adapted to be only pollinated by a
particular insect. Some flowers even resemble the mates insects to
attract them (mimicry).
• Mimicry - when an organism closely resembles another organism.
Usually provides some type of survival advantage.
3. Better seed protection and dispersal
• Angiosperm seeds are protected within a fruit structure of some sort.
(unlike the gymnosperms).
• Gymnosperm seeds are mainly spread by wind . Angiosperm seeds are
spread by many methods:
– A. wind dispersal - many seeds have parachutes (e.g. dandelion) or
propellers (e.g. maple trees seeds)
– B. Animal dispersal - some fruits are fleshy and are eaten by animals.
Animals often carry the fruit away to eat it. When they do, this frees
the seeds in a location far from the adult plant, cutting down on
competition. Often, seeds are adapted to pass through the digestive
system of an animal unharmed, landing in their own fertilizer! Some
fruits are adapted to stick onto animals fur. Theses are called Burs .
As the animal moves about, seeds are scattered.
4. Specialized tissues in Angiosperms to survive heat, cold and droughts.
• succulents - these are plants which have tissue specialized for water
storage. Plants such as cacti have tissues devoted to the storage of water
to survive long periods of drought.
Plants have a life cycle that consists of two generations:
1. Sporophyte generation
• diploid (cells have pairs of chromosomes - DNA material)
• produced by the fertilization of the female and male gamete
• produce spores through mitosis
2. Gametophyte generation
• haploid spores are produced by meiosis (cells have single
chromosomes)
• spores grow to become gametophytes (male and female)
• gametophytes produce female and male gametes
• Note: In non-vascular plants, the dominant generation is the
gametophyte. In vascular plants, the sporophyte generation is
dominant.
Analyze and explain the life cycle of a sample organism from the
Kingdom Plantae: “Fern”
Fern life cycle
• sporangium produce haploid spores which germinate to form
a gametophyte called a prothallus
• prothallus produces a male organ (antheridia) and a female
organ (archegonia)
• sperm from antheridia swim to egg in archegonia
• diploid zygote is made
• fertilized egg grows into a sporophyte
• sporophyte matures and develops roots and fronds (branches)
• sori (capsules) develop on pinnae (leaves)
• spores form in sori by meiosis
• refer to figure 6.9 on page 173
The Fern Life Cycle (ref. p 173, also fig. 6.9)
-study diagram on p. 173.
• reproduces sexually
• life cycle consists of two generation:
– 1. sporophyte
– 2. gametophyte
•
•
•
•
during the life cycle theses two generation alternate
life cycle is carried out on the floor of temperate forests
gametophyte generation is a heart-shaped prothallus
prothallus contains male and female structures:
– male structure - called antheridium ; produces sperm cells
– female structure - called archegonium; each archegonium produces a single egg cell
• The prothallus is the gametophyte generation. It is a tiny , heart - shaped
structure no bigger than a nickel, living on the forest floor.
• The prothallus has an antheridia and an archegonia. During wet conditions,
prothalli (plural for prothallus) release male sperm cells which swim to the
female archegonia, and fertilize the egg. This forms a zygote, which then grows
right out of the archegonia to develop into a mature sporophyte fern plant.
• The fern plant is the dominant body form in the alternation of generations.
Later, ferns develop sori, spore producing structures on the underside of their
fronds (a fern leaf is called a frond).
Section 6.3
• Kingdom Animalia
–p. 182 – 196
Animals are the largest of the 6
Kingdoms, and exhibit a great diversity
in form and function. The study of
animals is referred to as zoology.
• General characteristics of members of the
Kingdom Animalia:
•
•
•
•
Cell Type: Eukaryotic
Cell Wall: None
Body Form: all are Multicellular
Nutrition: Heterotrophic (ingestion)
– Animals have more complex systems than plants.
These systems are based on the animals nutrient
requirements. The do not photosynthesize, they
ingest their food.
• Nervous System: Present. Varies among
organisms.
• Reproduction: This may be through sexual or
asexual means. Asexual occurs in some lower
forms, sexual occurs in all higher forms.
• Locomotion: Yes. Most are motile at some point
in their lifetime.
• Animals are divided into two groups:
– Vertebrates: with a backbone and 5% of animal
kingdom.
– Invertebrates - without a backbone and remainder
of animals.
• Examples of members from Kingdom Animalia:
•
•
•
•
•
•
•
•
Mammals
Birds
Shellfish
Insects
Worms
Jellyfish
Sponges
Starfish
• Analyze and explain the life cycle of a sample organism
from the Kingdom Animalia: “Frog”
Frog life cycle
• external fertilization where the female lays a cluster of
eggs and male releases sperm on eggs
• young tadpole develop from fertilized eggs
• tadpoles have a tail from swimming and gills for respiring
• older tadpoles start to develop legs
• young frogs have well-developed legs but no tail
• adult frogs are adapted for life on land
• refer to figure 6.26 on page 193
•
•
•
•
•
•
Summary: External Fertilization, External
Development
Female lays cluster of eggs and the male
releases sperm directly onto the egg cluster.
The young tadpoles that hatch look very
different from adults. They contain gills for
respiring and have a tail for swimming.
Older tadpoles start to develop legs.
Young frogs have well-developed legs and has
lost it’s tail.
Adult frog is well adapted for life on land
ALSO SEE HANDOUTS ON FROG LIFE CYCLE*
Characteristics used to classify animals:
1. Body organization
2. Presence of digestive tract
3. Number of germ layers
4. Internal body cavity (coelum)
5. Body symmetry
• The number of germ layers refers to the layers
of cells. All animals except for two have three
germ layers.
• These are the ectoderm (outer layer),
endoderm (inner layer) and the mesoderm
(middle layer).
• In humans, the ectoderm produces skin, nerve
tissue and some sense organs.
• The endoderm produces the lungs, liver,
pancreas, bladder, and stomach lining.
• The mesoderm produces the muscles, blood,
kidneys and reproductive organs.
• The body symmetry involves the determination
of the front or head end, the back or tail end,
the dorsal (back) section, and the ventral (belly)
section.
• It determines the direction that the animal
moves.
• Sponges have shapes that are irregular or
asymmetrical.
• Most animals have symmetrical body plans
which are regular.
There are two types of symmetry in animals:
1. Radial symmetry is in animals with their
bodies organized equally around a central
vertical axis. These move in horizontal
directions around its centre. They can be
divided equally through the centre in many
different vertical planes.
2. Bilateral symmetry occurs when only one
cut can produce two equal, mirror-image
halves.
• A coelom is a fluid filled body cavity that holds
the digestive tract and other organs.
• Animals with coeloms are called coelomates
while those without a coelom are called
acoelomates.
• The coelom provides rigidity and the
development of more complex organ systems.
• Refer to Table 6.2 on page 183 to 184 for the
characteristics of the first 7 phylums.
Phylum Arthropoda
• 1. Most biologically successful and
abundant animal group on earth.
• 2. There are more arthropod
species than all other species
combined.
• 3. There are 1 million known
species.
• 4. Symmetry is bilateral.
• 5. Small coelom.
• 6. Jointed appendages for efficient
locomotion.
7. Exoskeleton that provides:
(a) protection of internal organs
(b) waterproof covering allowing
many to live on dry land (so they do not dry out)
8. Segmented body with parts
modified and fused to form specific
body regions:
(a) head - anterior
(b) thorax - middle
(c) abdomen - posterior
9. Possess a variety of well developed systems:
• a) Digestive
•
•
•
•
•
•
b) Respiratory
c) Excretory
d) Reproductive
e) Skeletal
f) Circulatory - open system
g) Nervous - well developed
with the following features:
(i) distinct brain
(ii) ventral nerve cord
(iii) sense organs such as eyes, auditory organs,
sensory bristles, and antennae that touch and sense
chemicals
10. The most successful class is class Insecta
with 900,000 known species.
• Nearly all are terrestrial with
a few freshwater and saltwater
forms
• Size range is broad; from 0.25
mm for some species of beetles
and up to 30 cm for some
tropical moths
The success of insects is credited to the following
reasons:
• (1) They are the only invertebrates
capable of flying. This allows them
to move over great distances to find
food, escape predators, and spread
to new environments.
• (2) There is tremendous variation in
how they are adapted for feeding
and reproduction, so they can exist
in all kinds of environments and
obtain nourishment from many
sources.
More Reasons
• (3) High rate of reproduction
and short life cycle. This
increases the ability of insects
to adapt.
• (4) Small in size. This means
they don’t need large areas to
live.
• (5) Social insects
• (6) Variations in body form
• Describe the differences that exist between
the invertebrate phyla (symmetry, body cavity,
reproduction, digestion).
• Describe the differences that exist between
the vertebrate taxa (symmetry, body cavity,
circulation, respiration, reproduction, and
endoskeleton).
*SEE TABLE HANDOUT*