23.1 animal characteristics · 2018. 4. 10. · 23.1 animal characteristics animals are the most...
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23.1 Animal Characteristics
EQ – Although diverse, what common characteristics do all
animal share?
Sea Slug
23.1 Animal Characteristics
Animals are the most physically diverse kingdom of
organisms and all are multicellular heterotrophs.
• Animals range in size from 25-meter-long blue whales
to microscopic rotifers.
• Animals are found nearly everywhere on Earth.
23.1 Animal Characteristics
All animals share a set of characteristics.
• All animals share a unique set of derived
characters.
• Animal cells are
supported by collagen.
– three-stranded
protein
– found in bone,
skin, ligaments,
fingernails,
and hair
23.1 Animal Characteristics
– diploid parents produce diploid offspring
• Animals are diploid and usually reproduce sexually.
Diploid cells have two copies of each chromosome:
one copy from the mother and one from the father
– do not have free-living haploid life stages
23.1 Animal Characteristics
– Homeotic genes control early development.
– Hox genes determine the position of cells differentiation.
– A Hox gene mutation leads to the development of a body structure in the wrong position.
• Most animals have Hox genes.
23.2 Animal Diversity
KEY CONCEPT - More than 95 percent of all animal species
are invertebrates.
Sea Slugs eat Sponges
23.2 Animal Diversity
Animals are grouped using a variety of criteria.
• Three criteria are used to categorize animals.
1. Body plan symmetry
- Bilateral
- Radial
2. Tissue layers
3. Developmental patterns
gastrovascular
cavity
mouth
mesoglea
oral arms
tentacles
blood vessels
brain
hearts
muscle
segmentnerve cord
mouth
digestive track
23.2 Animal Diversity
• There are two types of body plan symmetry.
– bilateral symmetry: body divides equally along one
plane
Animals with bilateral
symmetry can be
divided equally along
only one plane, which
splits an animal
into mirror-image
sides.
23.2 Animal Diversity
– radial symmetry: body arranged in circle around a
central axis
• There are two types of body plan symmetry.
– bilateral symmetry: body divides equally along one plane
Animals with radial symmetry
have body parts arranged in a
circle around a central axis.
23.2 Animal Diversity
• Bilateral animals have three
distinct layers of tissue; radial
animals have only two.
– both animal types have
ectoderm and endoderm
– bilateral animals have
mesoderm
• Animals are divided into two
major groups, the protostomes
and the deuterostomes.
– Protostomes form mouth-
first, and anus second.
– Deuterostomes first form the
anus and then the mouth.
23.2 Animal Diversity
A comparison of structure and genetics reveals the
evolutionary history of animals.Porifera Cnidaria Platyhelminthes
Annelida
Mollusca Nematoda ArthropodaEchinodermata
Chordata
RADIAL
1. NO TISSUES
5. PROTOSTOMES – first opening of digestive
cavity forms the mouth
6. DEUTEROSTOMES –
First opening
Of digestive cavity
Forms into anus
jellyfish, cora
l, a
nem
ones
sponges
fla
two
rms
Segm
ente
d
wo
rms
cla
ms, snails,
octo
puses
roundw
orm
s
cru
sta
cea
ns,
insects
, spid
ers
sea s
tars
,
sea u
rchin
s
lancele
ts,
vert
ebra
tes
2. TISSUES – groups of cells work together
3. RADIAL– body parts arranged in
a circle around a central axis4. BILATERAL– body divided equally
by one plane
23.2 Animal DiversityGeneral Characteristics of K. Animalia
1. Animals are multicellular.
2. The cells of animals are eukaryotic and the cells lack cell
walls.
3. Animals must obtain food from their environment.
(Heterotrophic) Animals are not capable of photosynthesis.
4. Most animals are motile because of a nervous system and a
muscular system. Three examples of animals that are sessile
(stationary) feeders are sponges, mussels and barnacles.
5. Most animals reproduce sexually.
6. The two major groups within the animal kingdom are
invertebrates and vertebrates.
7. In this kingdom the young usually have the same basic
features as the adults.
8. Organisms in Kingdom Animalia usually display a defined
shape or symmetry.
9. There are 30 different phyla in Kingdom Animalia.
23.2 Animal Diversity
Body symmetry:
23.2 Animal Diversity
Symmetry & Dissection Planes: