BIO 202 - Animal Biodiversity - Lecture 3

Flashcards covering animal biodiversity from a lecture, including animal evolution, development, and organogenesis.

How many phyla of animals have evolved since the Cambrian period?

No new phyla have evolved since the Cambrian period.

What happened to families and classes during global catastrophic extinction events?

Many families and classes went extinct.

What is the approximate timeframe of the Ediacaran Period?

Approximately 635 - 542 mya.

What is the approximate timeframe of the Cambrian Period?

Approximately 542 - 490 mya.

What characterized Stage 1 of the Cambrian Period?

Soft bodies leaving imprints in mudstone, oxygen levels below ~5%.

What event occurred around 575 mya during the Ediacaran Period?

The Avalon explosion.

What marks the end of the Cambrian Period?

Paleozoic Era ~485 mya

What advancements enabled zoologists to build the tree of life?

Gross morphology, early development, and genetic sequences. Dependent on technology like microscopes and molecular biology.

What are the six stages of animal development?

Gamete formation, fertilization, cleavage, gastrulation, organogenesis, and growth (Embryology).

What is spermatogenesis?

The process by which gametes (sperm) are produced in the testes.

What is oogenesis?

The process by which gametes (eggs) are produced in the ovaries.

What is the classification of oocytes based on?

Yolk amount and location (Oligolecithal, Mesolecithal, Polylecithal).

What events characterize fertilization?

Contact and recognition between egg and sperm, polyspermy prevention, sperm and egg membranes fuse, sperm tail disintegrates, sperm and egg nuclei fuse (diploid zygote).

What is cleavage?

Repeated cell divisions of the zygote resulting in smaller cells called blastomeres, without overall growth.

How does yolk amount and distribution affect cleavage?

It determines whether cleavage is holoblastic (whole) or meroblastic (partial).

What are the two major holoblastic cleavage patterns and what type of animal are they?

Spiral/determinate (protostomes) and radial/regulative (deuterostomes).

What is a blastula?

The stage after cleavage where the zygote is divided into many cells at the periphery, surrounding a fluid-filled cavity called the blastocoel.

What is gastrulation?

The process where one pole of the blastula pushes inward forming the archenteron (primitive gut) and blastopore.

What is the fate of the blastopore in protostomes?

The blastopore becomes the mouth.

What are the two germ layers formed during gastrulation?

Ectoderm and endoderm.

What is the mesoderm and how can it form?

A third germ layer in triploblastic organisms, forming either by schizocoely (Protostomes) or enterocoely (Deuterostomes).

Compare cleavage, gastrulation, and coelom formation between protostomes and deuterostomes.

Protostomes undergo determinate/spiral cleavage; the blastopore becomes the mouth, Mesoderm from split in mesodermal bands. Deuterostomes undergo indeterminate/radial cleavage; the blastopore does not form the mouth, Coelom from fusion of enterocoelous pouches.

What tissues are in diploblastic animals?

Epidermis (from ectoderm) and gastrodermis (from endoderm).

What is organogenesis?

The differentiation of the 3 embryonic germ layers into organs and tissues.

What does the ectoderm give rise to?

Outer epithelium (skin), nervous system.

What are gill arches involved in?

The formation of jaws, inner ear, tonsils, parathyroid glands and thymus in humans; gills and supportive structure in fish.

What does the endoderm give rise to?

The gut (digestive tube) and gill arches.

What does the mesoderm give rise to?

Support and movement structures like skeleton and muscles, circulatory system, urinary and reproductive organs.

How many phyla of animals have evolved since the Cambrian period?

No new phyla have evolved since the Cambrian period.

What happened to families and classes during global catastrophic extinction events?

Many families and classes went extinct.

What is the approximate timeframe of the Ediacaran Period?

Approximately 635 - 542 mya.

What is the approximate timeframe of the Cambrian Period?

Approximately 542 - 490 mya.

What characterized Stage 1 of the Cambrian Period?

Soft bodies leaving imprints in mudstone, oxygen levels below ~5%.

What event occurred around 575 mya during the Ediacaran Period?

The Avalon explosion.

What marks the end of the Cambrian Period?

Paleozoic Era ~485 mya

What advancements enabled zoologists to build the tree of life?

Gross morphology, early development, and genetic sequences. Dependent on technology like microscopes and molecular biology.

What are the six stages of animal development?

Gamete formation, fertilization, cleavage, gastrulation, organogenesis, and growth (Embryology).

What is spermatogenesis?

The process by which gametes (sperm) are produced in the testes.

What is oogenesis?

The process by which gametes (eggs) are produced in the ovaries.

What is the classification of oocytes based on?

Yolk amount and location (Oligolecithal, Mesolecithal, Polylecithal).

What events characterize fertilization?

Contact and recognition between egg and sperm, polyspermy prevention, sperm and egg membranes fuse, sperm tail disintegrates, sperm and egg nuclei fuse (diploid zygote).

What is cleavage?

Repeated cell divisions of the zygote resulting in smaller cells called blastomeres, without overall growth.

How does yolk amount and distribution affect cleavage?

It determines whether cleavage is holoblastic (whole) or meroblastic (partial).

What are the two major holoblastic cleavage patterns and what type of animal are they?

Spiral/determinate (protostomes) and radial/regulative (deuterostomes).

What is a blastula?

The stage after cleavage where the zygote is divided into many cells at the periphery, surrounding a fluid-filled cavity called the blastocoel.

What is gastrulation?

The process where one pole of the blastula pushes inward forming the archenteron (primitive gut) and blastopore.

What is the fate of the blastopore in protostomes?

The blastopore becomes the mouth.

What are the two germ layers formed during gastrulation?

Ectoderm and endoderm.

What is the mesoderm and how can it form?

A third germ layer in triploblastic organisms, forming either by schizocoely (Protostomes) or enterocoely (Deuterostomes).

Compare cleavage, gastrulation, and coelom formation between protostomes and deuterostomes.

Protostomes undergo determinate/spiral cleavage; the blastopore becomes the mouth, Mesoderm from split in mesodermal bands. Deuterostomes undergo indeterminate/radial cleavage; the blastopore does not form the mouth, Coelom from fusion of enterocoelous pouches.

What tissues are in diploblastic animals?

Epidermis (from ectoderm) and gastrodermis (from endoderm).

What is organogenesis?

The differentiation of the 3 embryonic germ layers into organs and tissues.

What does the ectoderm give rise to?

Outer epithelium (skin), nervous system.

What are gill arches involved in?

The formation of jaws, inner ear, tonsils, parathyroid glands and thymus in humans; gills and supportive structure in fish.

What does the endoderm give rise to?

The gut (digestive tube) and gill arches.

What does the mesoderm give rise to?

Support and movement structures like skeleton and muscles, circulatory system, urinary and reproductive organs.

What is the notochord?

A flexible rod that gives support in chordates and is the primitive axis of the embryo.

What is the