Keystone Biology Module 2 Part 2

There are two alleles for claw length in a certain mammal population.  Some members of the population have long claws that enable them to climb trees, while most do not.  When a new predator that feeds on these animals is introduced into this environment, some long-clawed animals climb up trees to escape. Which statement describes the most likely impact of natural selection on the population over the coming generations?

• The alleles for long claws will increase in the population.
• The alleles for long claws will decrease in the population.
• The alleles for short claws will increase in the population.
• The alleles for short claws will disappear from the population.

Tags

NGSS.MS-LS4-4

Which of these is most likely to be an abiotic component of a temperate grassland ecosystem?

• a layer of frozen soil called permafrost
• a population of large grazing mammals
• annual precipitation of 20cm to 100cm
• a temperature range from -40^oC to 10^oC

Tags

NGSS.HS-ESS2-4

Which statement can be described as a scientific law?

• Evolutionary change occurs slowly and steadily over a long period of time.
• The optimum temperature for most biochemical reactions in humans is about 37^oC.
• Different pairs of genes separate independently of each other when gametes are formed.
• The organelles of eukaryotic cells evolved from prokaryotic cells engulfed by other prokaryotes.

A forest fire destroys all animal and plant life in an area but leaves the soil intact.  Which is the most likely sequence of ecological succession in this area?

• trees ---> grasses ---> shrubs
• grasses ---> shrubs ---> trees
• grasses ---> lichens ---> shrubs
• lichens ---> grasses ---> shrubs

Tags

NGSS.MS-LS2-2

NGSS.MS-LS2-3

NGSS.MS-LS2-4

A scientist studies the relationship between temperature and the rate of cell division for a rare form of prokaryote that lives near hot undersea vents.  Which of these statements is a testable hypothesis?

• Prokaryotes reproduce by simple cell division.
• A prokaryote is defined by the absence of a nucleus.
• As temperature increases, the rate of cell division increases.
• The temperatures used in the experiment will range from 0^oC to 40^oC.

Tags

NGSS.MS-LS1-5

Which statement best describes how chromosomes are related to genes?

• Chromosomes are sequences of DNA within a gene.
• Chromosomes are copies of the genes of an organism.
• Chromosomes are all the different forms a gene can take.
• Chromosomes are structures that contain the genes of an organism.

Tags

NGSS.MS-LS3-1

For a population of small plants, the amount of sunlight is a limiting factor.  The small plants grow in the same area as a population of large trees.  If a disease kills off the population of trees, what effect will this most likely have on the population of small plants?

• The small plant population will increase without limit.
• The small plant population will decrease and then die out.
• The small plant population will increase and then level off.
• The small plant population will decrease and then increase.

Tags

NGSS.MS-LS2-1

NGSS.MS-LS2-2

NGSS.MS-LS2-4

A section of a gene has the following sequence of nitrogenous bases:  TGACAT.  If a frame-shift mutation occurs in this section, which of the following could be the mRNA strand coded from it?

• ACTGTA
• ACUGUA
• ACTGTTA
• ACUGUUA

Tags

NGSS.HS-LS3-2

Which of these factors drives the water cycle?

• runoff
• sunlight
• respiration
• precipitation

Tags

NGSS.MS-ESS2-4

Which statement correctly describes how a cell's DNA is replicated after the strands unwind?

• The double helix consists of two copies of the same strand, so copying one strand twice produces identical DNA.
• When the nitrogenous base "rungs" separate from the double helix "ladder", new complementary pairs take their place.
• The original strands are complementary, so each new strand built using complementary base pairs will match an original strand.
• The hydrogen bonds between complementary bases are too strong to be broken, so the sugar and phosphate groups are replaced with identical molecules.