BIO 102 - Chapter 17 Study Cards

In the evolution of the modern horse, which of the following was the goal of the evolutionary process? (a) large size (b) single toe (c) change in tooth size (d) change in tooth shape (e) none of these are correct

(a) large size

A change in expression of the Tbx5 gene can lead to which of the following mutations? (a) malformation of the legs (b) incorrect development of the eye (c) lack of development of neck vertebrae in a snake (d) development of six legs in a grasshopper (e) a shorter dorsal spine in stickleback fish

(a) malformation of the legs

Which of the following are an example of analogous structures? (a) wings of birds and bats (b) hooves of horses and deer (c) wings of moths and butterflies (d) leaves on oak trees and maples (e) arms of primates and cats

(a) wings of birds and bats

Which gene is incorrectly matches to its function? (a) Hox - body shape (b) Pax6 - body segmentation (c) Tbx5 - limb development (d) Pitx1 - pelvic-fin development (e) all of these choices are correctly matched

(b) Pax6 - body segmentation

The many species of Galapagos finches are each adapted to eating different foods. This is the result of (a) gene flow (b) adaptive radiation (c) sympatric speciation (d) genetic drift (e) all of these are correct

(b) adaptive radiation

The creation of new species due to geographic barriers is called (a) isolation speciation (b) allopatric speciation (c) allelomorphic speciation (d) sympatric speciation (e) symbolic speciation

(b) allopatric speciation

Allopatric, but not sympatris, speciation requires (a) reproductive isolation (b) geographic isolation (c) spontaneous differences in males and females (d) prior hybridization (e) rapid rate of mutation

(b) geographic isolation

Male moths recognize females of their species by sensing chemical signals called pheromones. This is an example of (a) gamete isolation (b) habitat isolation (c) behavorial isolation (d) mechanical isolation (e) temporal isolation

(c) behavioral isolation

A biological species (a) always looks different from other species (b) always has a different chromosome number than that of other species (c) is reproductively isolated from other species (d) never occupies the same niche as other species (e) does not survive long in the wild

(c) is reproductively isolated from other species

Which statement about speciation is not true? (a) speciation can occur rapidly or slowly (b) development genes can account for rapid separation (c) the fossil record gives no evidence that speciation can occur rapidly (d) speciation always requires genetic changes, such as mutations, genetic drift, and natural selection

(c) the fossil record gives no evidence that speciation can occur rapidly

Which of the following is not part of the gradualistic model evolution? (a) isolation of the population (b) a slow change of the population (c) the presence of fossils (d) an ancestral population that gives rise to two separate populations (e) a period of rapid change

(e) a period of rapid change

Which of the following events is part of macroevolution? (a) speciation (b) mutation (c) gene flow (d) natural selection (e) all of these are correct

(e) all of these are correct

Which of these is a prezygotic isolating mechanisms? (a) habitate isolation (b) temporal isolation (c) hybrid isolation (d) zygote mortality (e) both a and b are correct

(e) both an and b are correct

Which of these is an example of mechanical isolation? (a) sperm cannot reach or fertilize an egg (b) courtship patterns differ (c) organisms live in different locales (d) organisms reproduce at different times of the year (e) genitalia are unsuitable to each other

(e) genitalia are unsuitable to each other

variation in the expression of *what* genes produce different beak shapes in each of Darwin's finches?

BMP4 and CaM

hybrid is fertile, but the F2 generation of the F1 hybrid has reduced fitness

F2 fitness (postzygotic isolation)

What did Ernst Mayr, an evolutionary biologist, say about speciation?

Mayr said that when populations of a species become geographically isolated, microevolutionary processes, such as genetic drift and natural selection, alter the gene pool of each population independently. If differences between the groups become large enough, reproductive isolation may occur, resulting in the formation of new species.

gene involved in eye formation in all animals

Pax6

According to this concept, a species is the smallest set of interbreeding organisms, usually a population, that shares a common ancestor.

Phylogenetic species concept

How do scientists define species?

Scientists define species based on many types of evidence

In plants, if a diploid gamete fuses with a haploid gamete, a triploid plant results. The triploid plant is *STERILE* or *FERTILE*? Why or how?

Sterile, because the chromosomes cannot pair during meiosis

gene that controls the development of limbs, whether of the wing of a bird or the leg of a tetrapod

Tbx5

True or False: Microevolution and Macroevolution are the result of the same process , differing only in the scale at which they occur.

True

a type of speciation that occurs when a single ancestral species rapidly gives rise to a variety of new species as each adapts to a specific environment

adaptive radiation

the eventual result of populations that have become separated by a geographic or other type of physical barrier

allopatric speciation

occurs when two different but related species of plants hybridize

alloploidy

traits that evolve convergently in two unrelated lineages because of a response to a similar lifestyle or habitat are said to be *WHAT*?

analogous

occurs when a diploid plant produces diploid gametes due to nondisjunction during meiosis

autoploidy

what are the two types of polyploidy?

autoploidy alloploidy

What are some of the disadvantages to the morphological species concept?

bacteria and other microorganisms do not have measurable traits, similarities and differences between organisms can be very subtle and sometimes misleading, some organisms look so similar they appear to be the same species

courtship patterns that allow males and females in a species to recognize one another

behavioral isolation

This concept relies primary on reproductive isolation to identify different species.

biological species concept

occurs when a biological trait evolves in two unrelated species as a result of exposure to similar environments

convergent evolution

species that look almost identical but are very different in other traits, such as habitat or courtship behaviors

cryptic species

distinct physical characteristics

diagnostic traits

What results when competition is reduced and there is an opportunity for a species to expand its use of resources within habitats, providing an opportunity for new species to originate as populations become specialized to newly available microhabitats?

ecological release

This concept relies on identification of certain morphological traits to distinguish one species from another.

evolutionary species concept

What isolation mechanisms are POST-zygotic?

fertilization: zygote mortality hybrid sterility F2 fitness

the sperm of one species may not be able to survive in the reproductive tract of another species, or the egg may have receptors only for sperm of its species

gamete isolation

This model of macroevolution proposes that speciation occurs after populations become isolated, with each group continuing slowly on its own evolutionary pathway.

gradualistic model of evolution

When two species occupy different habitats, even in the same geographic range, they are less likely to meet and attempt to reproduce

habitat isolation

genes that determine the location of repeated structures in all vertebrates

homeotic (Hox) genes

traits that evolved because they came from a common ancestor

homologous

when a zygote dies because it is not viable, when two chromosome sets may fail to go through mitosis properly and not develop

hybrid inviability

when the zygote may develop into a sterile adult

hybrid sterility

mating between two species

hybridization

Reproductive barriers that prevent successful reproduction are called *WHAT* kind of mechanisms?

isolating

evolution on a large scale, involves speciation

macroevolution

when animal genitalia or plant floral structures are incompatible, reproduction cannot occur, prevents cross-pollination

mechanical isolation

Measured as change in allele frequencies in a population over generations, small-scale evolution within populations

microevolution

In phylogeny, a branch that contains all the descendants of a common ancestor is said to be ....?

monophyletic

Concept where species are distinguished from each other by one or more distinct physical characteristics.

morphological species concept

differences in appearance

morphology

This concept is used to identify species based on a common ancestor, a single ancestor or two or more different groups

phylogenetic species concept (evolutionary family tree)

a chromosome number beyond the diploid (2n) number

polyploidy

Isolating mechanisms that operate after the formation of a zygote and prevent hybrid offspring from developing and reproducing.

postzygotic isolating mechanisms

What isolation mechanisms are PRE-zygotic?

premating: habitat isolation temporal isolation behavioral isolation mating: mechanical isolation gamete isolation

Prevents reproductive attempts, makes it unlikely that fertilization will be successful if mating occurs.

prezygotic isolating mechanisms

explains the fluctuating pace of evolution, this model says that the assembly of species in the fossil record can be explained by periods of equilibrium, or stasis, punctuated (interrupted) by periods of rapid, abrupt speciation, or change

punctuating equilibrium model

term given to the process of natural selection that reinforces reproductive isolation, ex. the difference in color reinforces the choice to mate with their own species

reinforcement

physiological, behavioral, and genetic processes that inhibit interbreeding

reproductive isolation

for two species to remain separate, populations must be *WHAT* isolated, therefore gene flow must not occur between them.

reproductively

splitting of one species into two or more species

speciation

the splitting of one species into two or more species, of the transformation of one species into new species over time

speciation

speciation that occurs in the absence of a geographic barrier, more difficult to observe in nature because no physical barrier prevents mating between populations, as in allopatric speciation

sympatric speciation

A scientist who classifies organisms into groups

taxonomist

When species live in the same locale, but each reproduces at a different time of year, they don't attempt to mate

temporal isolation

the first cell that results when a sperm fertilizes an egg

zygote