General Biology 2: Chapter 20 - HW Q's

What type of evidence for evolution is provided by fossils?

Direct

Which of the following statements about marsupials in Australia is true?

For many types of placental mammals found throughout the world, there is a strikingly similar marsupial mammal in Australia.

The feet of modern horses have _______ toe(s); in contrast, early horses had _______ toe(s) on their front feet and _______toe(s) on their hind feet.

1, 4 , 3

Horses are members of an animal family that produced many extinct species and originated approximately ________ million years ago.

55

Contrary to the claims by supporters of intelligent design, the fossil record shows that many complex features of species such as the bones in the mammalian ear have _______.

evolved incrementally

A _______ structure has no apparent function in a species, but is fully functional in the species' ancestors.

Vestigial

Some species have anatomical features that have no apparent function but resemble structures of their presumed ancestors; these anatomical features are called _______.

Vestigial Strcutures

Why is it that some organisms do not appear to be perfectly adapted to their environment?

Because natural selection can only work on the variation present in a population.

______ evolution happens when two species from different lineages independently evolve similar characteristics because they occupy similar environments.

Convergent

Even though they serve different functions, the forelimb of a frog and the forelimb of a bat share structural similarities and are derived from a common ancestor. This makes these forelimbs an example of ________.

Homologous structures

Why are giraffe necks not perfectly suited for their function?

Like all mammals, giraffes only have 7 vertebrae in their necks which limits their flexibility.

All modern members of the horse family are large, _________ -legged, _______-running animals adapted to living in open ________.

Long, Fast, Grasslands

Which statement accurately describes the adaptations that result from natural selection

Natural selection does not always produce perfectly working adaptations, because it can only work on the genetic variation present in a population.

Which of the following are features of the vertebrate eye that make it a rather imperfect adaptation?

Nerve Fibers obstrcut the incoming light The photoreceptors face backwards, toward the wall of the eye As it exits the eye, the optic nerve creates a blind spot

The great variety of breeds of cats, dogs and other domestic animals have arisen through ________.

Artificial Selection

Which of the following are reasons why island trees belong to plant families that typically do not have tree members (for example the sunflower family)?

The tree niche is empty and so a flower can evolve through natural selection to be tree-like. Tree seeds rarely make it to isolated islands.

Today, fossils have been found that link ________

all major groups of vertebrates

When considering that Earth is a(n) ______ system, it is easy to see that evolutionary theory does not violate the second law of thermodynamics.

open

Molecular analysis of lactase DNA ________ in humans shows that genes for that enzyme have ________ evolved in Africa and Europe to produce the same result

sequences, independently

The fossil record shows that early species of horses were generally Blank______ in size, but many lineages since about 30 million years ago exhibit substantial change toward Blank______ in size.

small, an increase

Early horses inhabited woody areas where they probably browsed leaves and escaped predators by dodging through openings; this explains why those animals had ________ feet and ________ legs.

Broad, small

Which of the following is the most direct evidence for evolution?

Fossils

Which of the following statements about the horse family is true?

It originated 55 million years ago and over that time many of its members have become extinct

Relative Dating

Less Accurate Rocks are dated based on their position

Absolute Dating

More Accurate Rocks are dated based on changes in their isotopic composition

As a result of convergent evolution, many marsupial mammals of Australia look similar to _______ mammals found elsewhere and occupy a similar ecological niche.

Placental

Which of the following accurately describes the genes for hemoglobin in icefish that inhabit very cold Antarctic waters?

They have a hemoglobin gene which has many mutations, so they do not produce functional hemoglobin and have colorless blood.

How has the fossil record changed since Darwin's time?

Today the fossil record is far more complete

Even though there are gaps in the fossil record, some of the most direct evidence for evolution comes from _______ fossils that illustrate how certain major transformations in life forms occurred.

Transitional

Organisms that share a common ancestor often show similarities in their early _______ development before diverging into varied forms.

embryonic

The forelimbs of modern vertebrates are homologous structures, meaning that they may have changed evolutionarily to perform different functions, but they _______.

evoloved from the same body part in an ancestor

When fossils are arranged and compared according to their age, from oldest to youngest, successive _______ change becomes apparent.

evolutionary

Icefish that inhabit very cold water of the Antarctic have colorless blood because they lack the protein ________ , despite having the gene for making that protein (the gene has been rendered nonfunctional by many mutations).

hemoglobin