Evolution and Natural Selection

What does biological evolution involve in terms of genetic changes in a species?

• Changes in the physical appearance only

• Changes in the genetic makeup through natural processes

• Changes in individual behaviors only

• Changes in the species habitat preferences

Answer explanation

Biological evolution involves changes in the genetic makeup of a species through natural processes, not just physical appearance or individual behaviors.

Which hypothesis suggests that evolution of a species occurs in periods of rapid change?

• Gradualism

• Punctuated equilibrium

• Steady-state theory

• Catastrophism

Answer explanation

The correct choice is Punctuated equilibrium, which suggests that evolution of a species occurs in periods of rapid change.

Define natural selection.

• The process where organisms better adapted to their environment tend to survive and produce more offspring

• The breeding of domestic animals to enhance desirable traits

• The ability of a species to change its color

• The random mutation of genes in organisms

Answer explanation

Natural selection is the process where organisms better adapted to their environment tend to survive and produce more offspring.

True or False: Competition is a factor of natural selection.

• True

• False

Answer explanation

Competition is indeed a factor of natural selection as individuals compete for resources, mates, and survival, influencing which traits are passed on.

What is the result of natural selection acting upon phenotypes?

• No significant change occurs

• Only the genotypes are affected

• Phenotypes are selected based on environmental fitness

• All phenotypes are preserved equally

Answer explanation

Natural selection acts upon phenotypes by selecting those that are most fit for the environment, leading to changes in the population over time.

How has improved nutrition in humans over the past century affected their physical development?

• Decreased average lifespan

• Increased potential height

• Reduced genetic diversity

• Enhanced cognitive abilities

Answer explanation

Improved nutrition in humans over the past century has led to increased potential height due to better access to essential nutrients needed for growth and development.

What is an example of a change in elephant populations due to artificial selection pressures?

• Decreased size of ears

• Increased number of tusks

• Increase in tuskless elephants

• Enhanced memory capabilities

Answer explanation

The correct example of a change in elephant populations due to artificial selection pressures is an increase in tuskless elephants.

What is an adaptation in the context of evolution and natural selection?

• A genetic mutation that is harmful

• A process where species become less suited to their environment

• A characteristic that increases an organism's ability to survive and reproduce

• A temporary change in behavior in response to an environmental change

Answer explanation

An adaptation in the context of evolution and natural selection is a characteristic that increases an organism's ability to survive and reproduce.

How do mimicry and camouflage serve as examples of adaptation?

• They change the genetic makeup of organisms

• They help organisms to avoid predators or attract prey

• They are purely aesthetic changes

• They decrease the survival chances of organisms

Answer explanation

Mimicry and camouflage help organisms to avoid predators or attract prey, making them examples of adaptation.

What does the term "descent with modification" refer to in evolutionary biology?

• The process by which species do not change over time

• The inheritance of acquired characteristics

• The idea that new species are created from non-living matter

• The passing on of traits from parent organisms to their offspring, with gradual changes over time

Answer explanation

The passing on of traits from parent organisms to their offspring, with gradual changes over time