Speciation Chapter 7

1. Is there prezygotic or postzygotic barrier to reproduction? 2. what type of reproductive isolation? An odd number of chromosomes cannot pair up properly when the cell begins to divide the number of chromosomes in half from gametes, i.e., undergo ___.

1. postzygotic 2. reduced hybrid fertility

1. Is there prezygotic or postzygotic barrier to reproduction? 2. what type of reproductive isolation? First generation hybrids (F1's) are viable and fertile, but any grandoffspring are sterile or not viable

1. postzygotic 2. F2 Failure

1. Is there prezygotic or postzygotic barrier to reproduction? 2. what type of reproductive isolation? 3n seedless watermelons are produced by 3n hybrids of 4n and 2n parents, but can't themselves make gametes

1. postzygotic 2. reduced hybrid fertility

1. Is there prezygotic or postzygotic barrier to reproduction? 2. what type of reproductive isolation? A hybrid embryo forms and begins to develop but then soon dies.

1. postzygotic 2. reduced hybrid viability

1. Is there prezygotic or postzygotic barrier to reproduction? 2. what type of reproductive isolation? Female horses (mares) and male donkeys usually do not exhibit any sexual behavior in each other's presence, just ignoring each other even when the female is in heat.

1. prezygotic 2. behavioral reproductive isolation

1. Is there prezygotic or postzygotic barrier to reproduction? 2. what type of reproductive isolation? Drosophila melanogaster and D. simulans are very similar morphologically but their males' courtship looks different. They do not interbreed (hybridize) because, even though a male will court either species, females only respond to courtship from conspecifics (their own species).

1. prezygotic 2. mechanical reproductive isolation

1. Is there prezygotic or postzygotic barrier to reproduction? 2. what type of reproductive isolation? Genitals don't fit

1. prezygotic 2. mechanical reproductive isolation

1. Is there prezygotic or postzygotic barrier to reproduction? 2. what type of reproductive isolation? In many spiders, the male's sperm transfer organs have a species specific shape that matches the shape of the female's sperm receiving openings and won't fit in females of other species.

1. prezygotic 2. mechanical reproductive isolation

1. Is there prezygotic or postzygotic barrier to reproduction? 2. what type of reproductive isolation? Individuals do not mate because they are reproductively active at different times, e.g., different times of the day or different seasons.

1. prezygotic 2. temporal reproductive isolation

Horses have 64 chromosomes and donkeys have 62. So how many in each's gametes?

32 and 31 respectively

Bananas eaten in the U.S are mostly from __n plants, i.e., _____, meaning what?

3; triploid chromosomes are in triplet sets, where each set differs from other sets in length, placement of centromere, and/or banding pattern

A cross, aka a ___, between a donkey and horse has how many chromosomes?

63

where it is estimated to explain more than 1% 12% or 80% of extant species origin? Is this sympatric or allopatric speciation

80%; sympatric

the mare and donkey are what generation?

F0

what generation is the mule?

F1

F0, F1, F2 generations: which one is grandoffspring?

F2

another similar example in which many species evolved from probably a single initial colonization is seen with Drosophila-related flies on what group of American islands way out in the Pacific Ocean?

Hawaiian.

what does mules' reproductive isolation have to do with speciation?

This causes reproductive isolation between horses and donkeys and fits our definition of biological species.

a species that descended form three different parental species, and each set of chromosomes has 6 matching chromosomes is specifically called a ___.

allohexaploid

The 2 broades categories of speciation are what?

allopatric and sympatric speciation

If speciation came abut from there being minimal gene flow between the islands and the ecuador mainland and among the islands because the birds could not easily fly that far, would this be allopatric speciation or sympatric speciation?

allopatric speciation

Speciation with geographic isolation is known as ____, without geographic isolation is ___.

allopatric speciation; sympatric speciation.

the formation of which type of polyploid has to involve hybridization?

allopolyploid

if the change in chromosome number is from the combining of chromosomes from two or more species it is a ____; otherwise (if iti is from a single ancestral species), it is a ____./

allopolyploid; autopolyploid

if all the chromosomes in this new species came from a single original species, you can add the prefix

auto

The finches are known for their differences in their ____, which allows them to feed on different foods.

beaks

Using the ___ ___ concept means delineating species by who can interbreed and produce fertile offspring.

biological species

How are seedless watermelons produced?

chemicals are used to make some watermelons tetraploids, which produce gamets that combine with gametes of regular diploid watermelons to make triploid watermelon plants, which make fruit, but do not reproduce because they don't make seeds.

Isolated populations of the mouse Mus Musculus on the Portugues island of Madeira have different numbers of ____, which is unusual for a single species in animals. This was caused by what?

chromosomes; chromosome fusing

In most cells of most organisms, right before the cell splits, the number of ___ doubles, i.e., the DNA ______ itself. The end result is that each of the two "daughter" cells has the ___ number of chromosomes as the parent cell.

chromosomes; replicates; same

what are 3 examples of possible geographic barriers?

desert, water, mountain

in most animals, you can pair up their chromosomes (by appearance, e.g., shape, length) i.e., the animals are ____.

diploid

the process of fusion of two gametes is called ____, and it results in a _____.

fertilization; zygote

charles darwin studied 15 bird species with different sizes and shapes of breaks, birds that live on famous islands off the coast of Ecuador. These islands are called the _____ islands; and these birds are called _____.

galapagos; galapagos finches.

The presence of a long distance of water in between the islands will reduce which evolutionary process??

gene flow

mechanical isolation

genitalia between species are unsuitable for one another

the natural living place of an organism is its..

habitat

What usually happens to the number of chromosomes in a cell during meiosis?

halves

In a sperm that has 2 total chromosomes: is the sperm haploid or diploid?

haploid

in contrast their gametes' chromosomes are not paired i.e., there is only one of each type (type being based on banding pattern, length, shape) and so the gametes are ___=__n.

haploid=1n

an area where two species interbreed is known as a...

hybrid zone

To get an allopolyploid, besides there being a problem with meiosis or mitosis, there also has to have been _____.

hybridization

offspring produced from interbreeding of different species or varieties or strains is called...

hybridization

temporal isolation

in the mood in different seasons, months, etc.

We know the finches were not on the islands when the islands formed because the islands formed when _____

lava from volcanoes

The ancestral species of finches came over from the _____

mainland (south america)

Mules' parents are who?

mare (female horse), male donkey

In most cells of most organisms, when a cell forms gametes, what is the name of the process producing the gametes?

meiosis

The process in which the chromosomes double and split is called ___.

mitosis

If hybrids have low fitness, then reproductive isolation traits are expected to become more or lress common? and by what process?

more; evolution by natural selection

the ____ species concept is when organisms are grouped into species based on appearance, not based on ability to interbreed and produce fertile offspring.

morphospecies

the hybrid offspring of a mare and a male donkey is a...

mule

If a mare and a donkey mate, the resulting offspring is called a ____, and it typically produces how many offspring?

mule; 0

habitat isolation

not in the same place

behavioral isolation

not turned on by the same moves, touches, smells, colors, or sounds

what is an F2 generation?

offspring from breeding among the F1 generation.

the two species are called ____ species or the F__ generation

parent; 0

Where is polyploidy common?

plants

Speciation by polyploid is especially well documented in what kingdom of organisms?

plants (kingdom plantae)

an individual or species that has a chromosome number that is more than double the haploid number is a...

polyploid

Allopatric speciation begins with the formation of 2 or more ____ separated by what?

population; a geographic barrier

mechanisms that prevent interbreeding after zygote formation are called what?

postzygotic barriers

any mechanisms that prevent interbreeding before a zygote forms are called what?

prezygotic barriers

Complete reproductive isolation, where no genes are getting from one population to another is evidence that ___ has ocurred.

speciation

the process of new species evolving from old species is called ____.

speciation

Mistakes during meiosis can change the number of chromosomes in the gametes. If the individuals with a new number of chromosomes cannot interbreed and produce fertile offspring with individuals with the original number of chromosomes, then the process of ___ has occurred. The new species would be called a ___ polyploid if its number of chromosomes is a multiple of the number in the ancestral species.

speciation; polyploid

If there are hybrid zones between the populations, where they interbreed, the different populations might be considered the same _____, and given the information in this question, what would the species be? and what would the genus be?

species, provided the interbreeding results in fertile offspring Mus Musculus Mus

If 2 populations of fish become geographically isolated by an isthmus and the isthmus becomes underwater from melting glaciers causing sea levels to rise, those 2 populations will then be ___.

sympatric

two species (or 2 populations or 2 individuals) that live in the same place are said to be _____, whereas if they live in different places they are said to be ___.

sympatric; allopatric

Having to do with time

temporal

Our bread wheat descended from hybridyzation involving 3 different ancestral species, each of which was 2n=14. What does the 2 mean? what does the 14 mean? what was n for these species and what does it mean ?

the ancestral species' chromsomes were in pairs the total number of chromosomes in each nongamete-cell of these species was 14 seven set of chromosome pairs=the gametes of these species each have 7 different looking chromosomes

what if hybrids have the same fitness as nonhybrids?

then no selection against hybridizing (if there is mating with other species)

how are, e.g., tigers and lions, a complication to the biological species concept?

they rarely if ever interbreed in the wild, but occasionally they do in captivity; and when they do, the hybrids are usually sterile and short lived.

A tetraploid cell has ____ chromosomes as a diploid cell from the same species.

twice as many

the cell-split sometimes fails; if so there will only be one daughter cell, which will have how many chromosomes?

twice as many as the parent cell

in terms of reproductive isolation, what is true about mules?

usually sterile

What is the difference between viability and fertility?

viability is the ability to continue to develop fertility is the ability to produce gametes

Do two different species ever interbreed?

yes, hybridization