Activity 3-6 (gen.Zoology Lab)

sexually and asexually

most animals can reproduce both ____ and _____

asexual reproduction

produces genetically identical copies (ie. clones)

sexual reproduction

produces genetically unique offspring

asexual reproduction

makes identical copies (clones) of the parent

asexual reproduction

only a single parent is required and the process is much quicker

asexual reproduction

is beneficial when resources re abundant

Budding

a very common type of asexual reproduction especially in colonial animals

Budding colony

a new offspring begins as an outgrowth of the parent and may either remain attached and form a _____ or break away and begin an independent life

Hydra

budding example

Fragmentation

spontaneously break into many separate pieces which then regrow into a complete animal

starfish

example of Fragmentation

starfish

can regenerate new arms when one is broken off and sometimes a single arm can regenerate an entire organism

Polyembryony (twinning)

a type of asexual reproduction in which the embryo or larva (resulting from sexual reproduction) then clones itself into separate individuals

armadillo's

example of polyembryony

Armadillo's

typically produce 4 identical offspring from a single fertilized egg

Polyembryony

in some parasitic animals each different larva is able to clone copies of itself

Polyembryony

this allows a single egg to produce 100s of potential offspring and enhances chances that atleast a few will be able to find a new host to complete their life cycle.

-- in humans this process occurs occasionally to produce identical twins

Parthenogenesis (virgin birth)

This process only regularly occurs in nonhuman animals, both invertebrates and vertebrates

Parthenogenesis

the unfertilized egg is able to develop even though it has not been fertilized by a sperm.

Fertilization

sexual reproduction involves the ________

sexual reproduction

______ involves the fertilization of a females egg by a males sperm.

sexual reproduction

results in genetically unique individuals or offspring

sexual reproduction

provides much of the genetic variation required for evolution and adaptation

Gametes

Most variations in sexual reproduction depend on where the ________ come from or whether the developing egg has been fertilized or not

Monoecious Animals (Hermaphrodites)

_____ are those containing both male and female reproductive organs

15% of animals

about ______, especially those that are sessile (nonmotile) or parasitic, tend to be hermaphrodites

Clonorchis sinensis, Earthworm

example of Hermaphrodites

Dioecious animals

These are organisms that produce either male or female reproductive organs and gametes but never both at the same time.

Protandry

is the ability in some animals to switch their sex based on environmental cues such as changes in temperature

Crepidula shells

exanple of protandry

Sexual Dimorphism

sometimes it is impossible to distinguish the male from the female of a species by outward appearance

Dioecious animals

in other _____ the males and females are not identical, but differ in appearance, this showing dimorphism

Dimorphism

in addition to size, ____ may also result in differences in structures and color between genders

--for example, in most invertebrates the male is usually smaller than the female, while in vertebrates the female is usually the smaller one

-in birds the male is usually more brightly colored

Schistosoma male and female

Ascaris male and female

Growth and Development

all living organisms exhibit some form of _____ and _____

Animal Kingdom

members of the _____ have the most complex developmental cycles of any living organisms

Zygote, developmental cycle

the sequence of discrete, recognizable stages that these organism pass through as they develop from the formation of a ____ (the fertilized egg) to the sexually mature adult are referred to as it's _____

Gametogenesis

Fertilization

preembryonic development

embryonic development

post embryonic development

Animal Development can be subdivided into several sequential processes:

Growth

determination

differentiation

growth, determination, differentiation and morphogenesis

Embryonic development includes the processes of:

Gametes

are produced by the process of meiosis which differs from mitosis in that only one of each chromosome ends up in the cells after division

male gamete, the sperm

the ____, the ____ is small and almost always flagellated

female gamete

the ______ is usually large since it contains yolk and spherical

tail (flagellum)

head

sperm identify:

cell membrane

nucleus

egg identify:

Fertilization, Zygote

at _____ only a single sperm penetrates and fertilizes the egg to produce a ___

egg and sperm

the ___ and ____ each contribute a set of chromosomes so that the fertilized egg then has a pair of each chromosomes, one set from the male parent and the other set from the female parent

Fertilization cone

to prevent additional sperm from penetrating the egg a ____ ____ is produced to produce the original sperm into the egg quickly

Fertilization membrane, locks out

a ____ expands around the egg and pushes away and "_____" other sperm cells

preembryonic development

the zygote begins to divide to produce a multicellular embryo

Cleavage

Morula

Blastula

Gastrula

Preembryonic development:

Cleavage

the first identifiable period of development occurs as the fertilized egg begins to divide

cleavage divisions, blastomeres

these early divisions are called _____ and each cell produced is an identical genetic copy of the zygote and is called a ____

blastomeres

note that 2, 4, 8

Morula

Continued division leads to a solid ball of cells called the ____

blastula

cell division continues until the embryo becomes a hollow ball of cells. if the embryo is spherical, it is called ____

blastocoel

the cavity inside the blastula is called the _____

blastopore

the archenteron opens to the outside through the _____

mouth or anus

the blastopore will eventually become either the ___ or the ____ of the adult anima

ectoderm

endoderm

Mesoderm

​ectoderm, mesoderm, and endoderm

3 embryonic tissue layers

ectoderm

the ___ will eventually become the skin and nervous system

Mesoderm

the ____ will become the skeletal system, muscular system and circulatory system

Endoderm

the ___ will develop into the respiratory and digestive system

embryo

after the 3 embryonic tissue layers are formed in the gastrula l, the immature animal is referred to as an ____

embryonic development

during ____ the organs and organ systems form

larvae

nymphs

fetuses

the animal embryo may next develop into any of several forms such as ____, _____, ______

larval form

in many animals, the embryo soon develops into a free _____

Larvae

_____ are an immature stage which move and feed independently and often have no resemblance at all to the adult of the species

larvae

while each phylum or class often has its own characteristics ____

similar ancestry

Similar larvae imply _____

similar ancestry

indicating that the taxa are relatively closely related

planula larva

a simple multicellular, oval larva with no discernable organs, it's surface is covered with cilia for movement common in jellyfish and some flatworms

Nauplius larva

a triangular larva with three pairs of jointed appendages, eyespots, and digestive organs

- larvae of crustaceans such as shrimps and crabs

Glochidia larva

are larvae of freshwater clams that are parasitic on the gills of fish until they mature and fall to the sediment and begin life as free-living clams

Caterpillars, maggots, grubs, tadpoles

are examples of larvae that look and feed quiet different than the adults that they become

Nymphs

are immature stages of animals that atleast somewhat resemble the adult of the species and that live and feed independently

Fetus

vertebrates (higher animals) produce an immature stage that does resemble the adult but that is usually completely dependent on the mother (or enclosing egg) for nutrition and protection

Animal Kingdom (Metazoans)

the largest kingdom in terms of the number of different kinds of species is the _____

animal's

____ are represented by a very diverse array of sizes shapes and forms from very simple to extremely complex, including the "human animal"

Heterotrophs

all animals are multicellular ____

1. multicellular eukaryotic organisms

2. cells with no cell wall or chloroplast l and more mitochondria