bio diversity final study guide

What defines life?

Something that metabolizes, grows, and reproduces.

What are the ways humans gain knowledge?

Experiential, religious, and scientific methods.

Who calculated the age of the Earth to be approximately 6000 years?

Archbishop Ussher in the 1640s.

What was the 1800s belief about the origin of life from non-living matter called?

Spontaneous generation.

Who proposed the 'Primordial soup hypothesis'?

A.I. Oparin and J.B.S. Haldane.

How do we estimate the age of the Earth?

Radiometric dating of minerals in igneous rocks, meteorites, and moon rocks.

What geological process explains why not all igneous rocks on Earth are the same age?

Plate tectonics.

Where do we get clues about the early Earth's conditions?

Volcanoes and other planets.

What were the primary energy sources on early Earth?

Radioactive, electrical, UV, and geothermal energy.

Who conducted the 'Miller-Urey experiment'?

Stanley Miller.

What did the Miller-Urey experiment demonstrate?

Formation of building blocks of life (amino acids, fatty acids, adenine).

Where might processes that led to the origin of life have been enhanced?

Hydrothermal vents.

What type of organisms were the earliest life forms?

Non-photosynthetic, anaerobic bacteria.

What metabolic process did early life use to degrade organic molecules?

Anaerobic fermentation.

What type of bacteria originated photosynthesis and produced oxygen?

Photosynthetic anaerobic bacteria (cyanobacteria).

What geological formations resulted from the reaction of iron with oxygen produced by early photosynthetic organisms?

Banded iron formations (Fe2O3).

What acted as an 'oxygen-sponge' and absorbed oxygen for over a billion years?

Iron.

What types of organisms evolved as a result of increasing oxygen levels?

Aerobic heterotrophs and aerobic autotrophs.

What major evolutionary events occurred between 1.8 and 1.4 billion years ago?

Oxidative metabolism, eukaryosis, advent of sex, and biodiversity increase.

What evidence supports the evolution of eukaryotes from prokaryotes?

Mitochondria and chloroplasts retain genetic material.

What are the key processes involved in the origin of sex?

Reduction division (meiosis) and recombination.

What major evolutionary events occurred between 700 and 540 million years ago?

Origin of metazoa, Ediacaran fauna, O2 levels surpass 10%, Cambrian 'explosion'.

What hypothesis explains the origin of metazoa from protists?

Colonial Flagellate Hypothesis.

What are the characteristics of Stage 1 of the Cambrian Period?

Soft bodies, imprints in mudstone, oxygen below 5%.

What are the characteristics of Stage 2 of the Cambrian Period?

Hard part fossils, oxygen above 5%, ~34 phyla from this point onward.

What are the three major eras in the history of animal life?

Paleozoic, Mesozoic, and Cenozoic.

Which global mass extinction event killed ~96% of species?

End Permian period.

What caused the mass extinction at the end of the Cretaceous period?

Chicxulub impactor.

What is the name of the current extinction event?

Holocene extinction.

Approximately how many phyla of animals are there?

~34

When did all animal phyla evolve?

Ediacaran/Cambrian (~600-500 mya).

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

What three things have Zoologists used to build the 'tree of life'?

Gross morphology, Early development, and Genetic sequences

What are some animal body plans?

Symmetry, Segmentation, Body cavities, Modularity / coloniality , Constrained and unconstrained body plans, Hydrostatic skeletons, Exoskeletons, and Size and shape

What are the three types of symmetry?

Radial, Asymmetry, and Bilateral

What is cephalization?

Differentiation of the head

What is segmentation?

Repetition of structures along the longitudinal axis of the adult body that result from a linear series of mesodermic somites (muscle units) formed during embryonic development.

What are the two types of body cavities?

Pseudocoelom and Coelom

What is modularity?

Increasing body size by adding new units

What are ramets?

Morphologically and genetically identical units that are usually interconnected

What animal phylum is modularity found in?

Porifera (sponges)

What are the three constraint levels of body plans?

Highly constrained, Moderately constrained, and Unconstrained

What are animals with hydrostatic skeletons?

Nematoda and Annelida