Animal Reproduction classification

What it is called when the union of sperm and egg takes place outside the bodies of the parents?

External fertilization

The layer of cells on the inner surface of the gastrula is called what? What will this layer eventually become?

The layer of cells on the inner surface is called the endoderm. This layer will eventually become the animal's digestive tract and digestive organs.

The layer of cells on the outer surface of the gastrula is called what? What will this layer eventually become?

The layer of cells on the outer surface is called the ectoderm. This layer will eventually become the skin and nervous tissue of the animal as well as any other body covering (examples: fur and scales).

What it is called when the union of sperm and egg takes place inside the female's body? What is required for this to happen?

Internal fertilization occurs inside the female's body. Copulation is required to facilitate the reception of sperm by a female. Males typically have a penis for depositing sperm into the vagina of females.

What changes happen as a result of the activation of the egg?

1. Increase of cytoplasmic calcium (Ca2+), which hardens the egg lining. 2. The nucleus of the sperm and egg fuse to form the diploid zygote.

What are the disadvantages of sexual reproduction?

1. Organism must use energy to produce gametes. 2. Organism may have to change pattern of activity to reproduce. 3. Some reproductive behaviors may attract predators. 4. Some species lead to deadly competition between males.

What three lifestyle traits are often seen in hermaphroditic animals?

1. Some hermaphrodites can self-fertilize (example: tapeworms) 2. Some cannot self-fertilize and must exchange sperm to fertilize each other's eggs (example: some snails) 3. Simultaneous hermaphrodites have the potential to produce twice as many offspring as could a dioecious species in which half the individuals are nonproductive males.

What are the two main types of gonads and what does each produce?

1. Testes produced sperm 2. Ovaries produce eggs

What are the main advantages of bilateral symmetry?

1. These organisms can be divided down their length into similar left and right halves. 2. These organisms tend to me active and move forward at an anterior end. 3. These organisms have various degrees of cephalization. 4. They can find food and mates and avoid predators because they have sensory organs and good muscular control.

What are the main advantages of radial symmetry?

1. These organisms can be divided through a central axis into roughly equal halves. 2. These organisms tend to be sessile or sedentary. 3. These organisms can reach out in any direction from their center, which is good for sensing food and predators.

Name two animals that have a blind or incomplete gut.

Anemones and flatworms are animals with a blind gut, or gastrovascular cavity.

What do we call the primitive gut at the center of the gastrula?

Archenteron

What group of animals have radial cleavage, regulative embryo development, an enterocoelous, and a blastopore that becomes their anus?

Deuterostomes

What do we call animal species that have separate sexes?

Dioecious

What do we call animals that have only two germ layers?

Diploblasticioup

What animals are simultaneous hermaphrodites and what does that mean?

Earthworms are simultaneous hermaphrodites, which means that during mating each partner passes sperm from genital pores along grooves to seminal receptacles of its mate. Both produce sperm to fertilize each other's eggs.

What is cephalization?

Cephalization: concentration of sensory tissues at the anterior end.

What percent of animals are invertebrates?

About 95% of animals are invertebrates. (invertebrates: animals without backbones).

What do we call animals without a coelom?

Acoelomates

What is asexual reproduction?

Asexual means without sex' and require only one parent.

What is the main disadvantage of asexual reproduction?

Because all of the organisms are genetically identical, they share the same weaknesses, so if the environment changes it could be deadly to all. The environment has to be stable in order for these organisms to survive.

What do we call the central fluid-filled cavity in the center of the cell layer?

Blastocoel

What do we call the small, maneuverable cells that make up the morula?

Blastomeres

What is budding? What is animals frequently use budding?

Budding is an unequal division of an organism. In other words, an outgrowth, or bud, forms and separates forms and separates from the parent to develop as individual. Cnidarians, including Hydras, frequently use budding.

What is cleavage?

Cleavage is the process of rapid cell divisions (mitosis).

What is it called when a sea anemone or planarian body breaks into two or more parts, each of which will from a new organism?

Fragmentation

What animal can use gemmules to survive harsh seasons?

Freshwater sponges in the winter.

What is the main advantage of sexual reproduction?

Genetic diversity allow species to survive changing environmental conditions.

What two terms can be used for animals that have both male and female reproductive organs?

Monoecious or hermaphrodites

What are the advantages of asexual reproduction?

Numerous offspring can be produced without the parent losing a lot of energy or time.

The process in which unfertilized eggs can develop into new individuals is called what?

Parthenogenesis (examples: bees or ants)

What is it called when a piece of an organism becomes detached and develops into new individuals is called what?

Parthenogenesis (examples: starfish)

What group of animals have radial cleavage, regulative embryo development, an enterocoelous, and a blastopore that becomes their anus?

Protostomes

What group of animals have spiral cleavage, mosaic embryo development, a schizocoelous, and a blastopore that becomes their mouth?

Protostomes

Name the five groups of animals that are vertebrates.

Reptiles, mammals, human, amphibians, birds, etc. (vertebrates: animals with backbones).

What type of worm has a pseudocoelom?

Roundworms

Sessile organisms often have what type of symmetry?

Sessile organisms often have no symmetry

Which stage of development is represented by a hollow, fluid-filled ball of cells?

The blastula stage of development.

Name the process of uniting male and female gametes and the cell that is produced.

The process is fertilization and the cell that is produced is a zygote.

What is spawning?

The release of sperm and eggs into the water is called spawning. This release is often synchronized.

What do we call the third germ layer and what will this layer eventually become?

The third germ layer is called the mesoderm. This layer will eventually become the skeleton and muscles (muscoskeletal system), circulatory system, excretory system, reproductive system, and in some animals, the respiratory system.

What animals are sequential hermaphrodites and what does that mean?

ome fish, such as Clownfish, are sequential hermaphrodites, which means that they have a genetically programmed sex change within an individual organism. In other words, they are born one gender and then change to the opposite.