Middle School Life Science : Middle School Life Science

Study concepts, example questions & explanations for Middle School Life Science

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55 Practice Tests Question of the Day Flashcards Learn by Concept

Example Questions

Example Question #2 : Explain How Genetic Variation Increases Chances Of Survival

Which of these processes is most important for genetic variation?

Possible Answers:

meiosis

cellular respiration

mitosis

asexual reproduction

Correct answer:

meiosis

Explanation:

The answer is meiosis because that is where "crossover" and recombination of DNA take place in sexual reproduction, increasing genetic variation of offspring.

A genetically diverse population of individuals is more likely to survive than a population of individuals with similar genetic makeup. Variation allows some individuals within a population to adapt to the changing environment and natural selection allows the expression of those beneficial traits to persist. For example, if a population of organisms has the same genetic makeup, it is far less likely to survive disease, drought, or predation than one with genetic variation.

Example Question #3 : Explain How Genetic Variation Increases Chances Of Survival

Screen shot 2020 06 10 at 1.14.54 pm

According to this diagram, what will increase genetic variation most?

Possible Answers:

no crossing over

cell division

DNA replication

crossing over

Correct answer:

crossing over

Explanation:

The answer is "crossing over" because it will produce 4 genetically different offspring.

A genetically diverse population of individuals is more likely to survive than a population of individuals with similar genetic makeup. Variation allows some individuals within a population to adapt to the changing environment and natural selection allows the expression of those beneficial traits to persist. For example, if a population of organisms has the same genetic makeup, it is far less likely to survive disease, drought, or predation than one with genetic variation.

Example Question #4 : Explain How Genetic Variation Increases Chances Of Survival

Imagine there are 3 populations of snow hares. Snow hares have different colored fur ranging from white to brown. White snow hares can hide from predators more easily in the snow, and light brown snow hares can hide more easily in the grass and brush when the snow melts. Which of these populations of snow hares is most likely to survive this a winter with constantly changing weather and unpredictable snow?

Population 1: All the snow hares are completely white
Population 2: Most of the snow hares are completely white, but some of them have brown splotches.
Population 3: There are many snow hares of all different colors from completely white to completely brown.

Possible Answers:

not enough information

population 3

population 2

population 1

Correct answer:

population 3

Explanation:

The answer is population 3 because it has the most genetic variation.

A genetically diverse population of individuals is more likely to survive than a population of individuals with similar genetic makeup. Variation allows some individuals within a population to adapt to the changing environment and natural selection allows the expression of those beneficial traits to persist. For example, if a population of organisms has the same genetic makeup, it is far less likely to survive disease, drought, or predation than one with genetic variation.

Example Question #5 : Explain How Genetic Variation Increases Chances Of Survival

Why is genetic variation important to a population?

Possible Answers:

It helps keep individuals looking different enough to tell each other apart.

It allows a population to adapt in response to changing environments.

It keeps a population the same despite constantly changing environments.

The environment doesn't change so there is no need for genetic variation.

Correct answer:

It allows a population to adapt in response to changing environments.

Explanation:

The answer is "it allows a population to adapt in response to changing environments."

A genetically diverse population of individuals is more likely to survive than a population of individuals with similar genetic makeup. Variation allows some individuals within a population to adapt to the changing environment and natural selection allows the expression of those beneficial traits to persist. For example, if a population of organisms has the same genetic makeup, it is far less likely to survive disease, drought, or predation than one with genetic variation.

Example Question #6 : Explain How Genetic Variation Increases Chances Of Survival

Which genetic process is LEAST likely to add a variety of new traits to an individual?

Possible Answers:

accurate replication

crossover and recombination

deletion of DNA

genetic engineering

Correct answer:

accurate replication

Explanation:

The answer is "accurate replication."

A genetically diverse population of individuals is more likely to survive than a population of individuals with similar genetic makeup. Variation allows some individuals within a population to adapt to the changing environment and natural selection allows the expression of those beneficial traits to persist. For example, if a population of organisms has the same genetic makeup, it is far less likely to survive disease, drought, or predation than one with genetic variation.

Example Question #7 : Explain How Genetic Variation Increases Chances Of Survival

A population of ferns is exposed to the same amount of a toxic chemical and only a few of the mushrooms survive. What is the best explanation for the resistance of some of the mushrooms to the chemical's effects?

Possible Answers:

developed in response to the chemical being applied

resistance was passed down from the top of the food chain

immunity was transferred from the chemical

the presence of mutations in individual mushrooms

Correct answer:

the presence of mutations in individual mushrooms

Explanation:

The answer is "the presence of mutations in individual mushrooms."

A genetically diverse population of individuals is more likely to survive than a population of individuals with similar genetic makeup. Variation allows some individuals within a population to adapt to the changing environment and natural selection allows the expression of those beneficial traits to persist. For example, if a population of organisms has the same genetic makeup, it is far less likely to survive disease, drought, or predation than one with genetic variation.

Example Question #8 : Explain How Genetic Variation Increases Chances Of Survival

One explanation for the variety of species on Earth today is:

Possible Answers:

The environment was unchanging in Earth's early history, setting the stage for evolution.

Genetic variation allows new species to develop and adapt to ecological niches

Individuals in a population can change their bodies to meet their needs in an ever changing environment.

Each ecological niche changes in response to the organisms that live within it.

Correct answer:

Genetic variation allows new species to develop and adapt to ecological niches

Explanation:

The answer is "Genetic variation allows new species to develop and adapt to ecological niches."

A genetically diverse population of individuals is more likely to survive than a population of individuals with similar genetic makeup. Variation allows some individuals within a population to adapt to the changing environment and natural selection allows the expression of those beneficial traits to persist. For example, if a population of organisms has the same genetic makeup, it is far less likely to survive disease, drought, or predation than one with genetic variation.

Example Question #9 : Explain How Genetic Variation Increases Chances Of Survival

Which situation represents traits that are inheritable?

Possible Answers:

A hamster has a gene which codes for long fur. Its offspring has long fur.

A puppy sees its mother chase its tail. So it does the same thing.

A random mutation causes the immediate death of an amoeba.

A sea turtle is hit by a motor boat. It survives, but damage is done to the shell.

Correct answer:

A hamster has a gene which codes for long fur. Its offspring has long fur.

Explanation:

The answer is "a dog has a gene which codes for long fur. Its offspring has long fur."

A genetically diverse population of individuals is more likely to survive than a population of individuals with similar genetic makeup. Variation allows some individuals within a population to adapt to the changing environment and natural selection allows the expression of those beneficial traits to persist. For example, if a population of organisms has the same genetic makeup, it is far less likely to survive disease, drought, or predation than one with genetic variation.

Example Question #10 : Explain How Genetic Variation Increases Chances Of Survival

The LEAST genetic variation would be found in which of the following populations?

Possible Answers:

birds that reproduce on an island isolated from other habitats

salamanders that occupy many different ecological niches

microbes that reproduce asexually by budding

a population of fungi that just survived a disease

Correct answer:

microbes that reproduce asexually by budding

Explanation:

The answer is "Microbes that reproduce asexually by budding" because asexual reproduction produces genetic clones.

A genetically diverse population of individuals is more likely to survive than a population of individuals with similar genetic makeup. Variation allows some individuals within a population to adapt to the changing environment and natural selection allows the expression of those beneficial traits to persist. For example, if a population of organisms has the same genetic makeup, it is far less likely to survive disease, drought, or predation than one with genetic variation.

Example Question #121 : Middle School Life Science

What is meiosis?

Possible Answers:

a process of cell division that happens before mitosis

a process of cell division in asexual reproduction

a process of cell division for replacement of cells

a process of cell division in sexual reproduction

Correct answer:

a process of cell division in sexual reproduction

Explanation:

Meiosis is a process where a single cell divides twice to produce four sex cells containing half the original amount of genetic information. These daughter cells are all genetically identical. Since the four daughter cells only have half the number of chromosomes of the parent cell, they are considered haploid. The main purpose of meiosis is to produce sex cells which are later combined in sexual reproduction to increase genetic variation. Meiosis is where crossover and recombination can take place, further increasing the genetic variation of daughter cells.

Some key differences between meiosis and mitosis are: Mitosis involves the division of body cells, while meiosis involves the division of sex cells. Two daughter cells are produced in mitosis, while four are produced in meiosis. Mitosis daughter cells are diploid, but meiosis daughter cells are haploid. Meiosis creates more genetic variation than mitosis.

 

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