answer.
Ask question
Login Signup
Ask question
All categories
  • English
  • Mathematics
  • Social Studies
  • Business
  • History
  • Health
  • Geography
  • Biology
  • Physics
  • Chemistry
  • Computers and Technology
  • Arts
  • World Languages
  • Spanish
  • French
  • German
  • Advanced Placement (AP)
  • SAT
  • Medicine
  • Law
  • Engineering
Dmitry_Shevchenko [17]
2 years ago
3

Stickleback fish are found in both marine and freshwater habitats. The marine fish have no scales but have hardened, armorlike p

lates along their sides. The plates are thought to protect sticklebacks from certain predators. In the late 1980s, sticklebacks from a marine population colonized Loberg Lake, a freshwater lake in Alaska. Starting in 1990, researchers sampled fish from the lake every four years and recorded the armor-plate phenotypes of the male sticklebacks in each sample. The armor-plate phenotypes were categorized as either complete (plates extending from head to tail), partial (plates extending from head to abdomen), or low (a few plates near the head only). The results are shown in the table below. ARMOR-PLATE VARIATION IN THE STICKLEBACK POPULATION OF LOBERG LAKE Year 1990 1994 1998 2002 2006 Percent of Males in the Sample with Each Armor-Plate Phenotype Low Partial Complete 1% 2% 97% 45% 14% 41% 58% 16% 26% 76% 15% 9% 90% 6% 4%
14. Which of the following is an independent variable in the investigation?
(A) Year in which the sample was collected
(B) Salinity of the water in Loberg Lake
(C) Size of the stickleback population
(D) Percent of males with each armor-plate phenotype
15. To evaluate the reliability of the results, it would be best to know which of the following?
(A) The surface area of Loberg Lake
(B) The number of males in each sample
(C) The average daily temperature of Loberg Lake
(D) The age of the sticklebacks in each sample
Biology
2 answers:
Zigmanuir [339]2 years ago
7 0

Answer:

<em>14. Which of the following is an independent variable in the investigation? </em>(A) Year in which the sample was collected

<em>15. To evaluate the reliability of the results, it would be best to know which of the following?</em> (B) The number of males in each sample

Explanation:

  • Independent (manipulated) variable: Refers to all the variables in an experiment that provoke a response in another variable. An independent variable is the one that changes or is controlled and modified in the experiment to analyze how another variable responds to it. It changes to analyze its effects on the dependent variable. Usually, the independent variable is represented by the X letter. In the exposed example, the Year in which the sample was collected is an independent variable.

Probably the year in which the sample was collected is not the cause of phenotypes differentiation between males, but it is a variable that reflects the change of armor-plate through the years. With this information, scientists can make assumptions and reach a conclusion about the phenotypic variation of the trait in sweet water through the years.  

  • The sample size is very important during a scientific investigation. The correct sample size depends on the investigation project. We need to study a correct amount of individuals to obtain conclusive and reproducible results or, on the contrary, the results will not be informative or robust at all. When sampling wild animals, many times it is difficult to obtain the ideal number of individuals, especially in aquatic animals that are hard to reach, so we have to manage with the amount that we are able to get. However, if we are working with a few individuals, or the samples are not comparable in size with each other, it is very important to consider this in the discussion and conclusions of your work. The risk with small-sized samples is that we might be studying individuals with extreme phenotypes that are not representative of the whole population. This is why it is important to get a certain number of animals, to analyze those that are most representative, and eliminate the outliers.

In the exposed example, per sample, we need to get approximately the same amount of male fishes to perform a reliable comparison between years and the phenotypic changes in time.

   

Sonja [21]2 years ago
3 0

Answer:

14. A

15. B

ALL THE BEST FOR AP EXAMS BUDS

You might be interested in
What current will an ammeter register if 960C of charge flow through it in 2 minutes?
postnew [5]

Answer:

8A

Explanation:

I= Q/t, where

I= current (A)

Q= charge (C)

t= time (s)

First convert the time from minutes to seconds.

1 minute= 60 seconds

2 minutes= 2×60= 120 seconds

Using the formula,

I= 960÷120

I= 8A

7 0
2 years ago
When acetylcholinesterase outlasts the release of acetylcholine from the synaptic vesicles, the skeletal muscle __________?
IceJOKER [234]

Answer:

relaxes

Explanation:

Acetylcholine is the substance responsible for the transmission of nerve impulses from pre-postganglionic neurons, in the ganglia of the autonomic nervous system. At the level of the parasympathetic nervous system, the transmission between the postganglionic neuron and the effector organ also mediates. In addition, it is the mediator of the nerve transmission of the terminal motor plate.

There are large differences in the effects that Acetylcholine triggers at different cholinergic transmission sites

Intra-arterial injection near Acetylcholine produces muscle contraction similar to that caused by motor nerve stimulation. Decreased resting potential in isolated intestinal muscle and increased frequency of spike production, accompanied by increased tension. In the cardiac conduction system, nodes S-A and A-V, it produces inhibition and hyperpolarization of the fiber membrane; and pronounced decrease in depolarization speed. Central regulation of extrapyramidal motor function. Exciting effect of the basal ganglia that counteracts the inhibitory action of Dopamine. Although cholinergic innervation of blood vessels is limited, cholinergic muscarinic receptors occur in sympathetic vasoconstrictor nerves. The vasodilator effect on isolated blood vessels requires the presence of an intact endothelium. The activation of muscarinic receptors causes the release of a vasodilator substance - <u>relaxing factor derived from the endothelium - that diffuses to the smooth muscle producing </u><u>relaxation</u><u>.</u>

4 0
2 years ago
How can light energy solve real-life problems?
ahrayia [7]

Answer:

It helps us to see things.

It helps plants to make food and grow.

It is used in power satellites and space stations.

It is used in many electronic appliances.

The energy of light from the sun can be harvested to solar panels and can be used for domestic use since it is eco-friendly and cost effective too.

Explanation:

7 0
2 years ago
the graph below shows the percent of seeds from two plant species that sprout when grown in water containing different amounts o
Akimi4 [234]
What are the answer choices?
6 0
2 years ago
Select the correct answer from each drop-down menu.
aksik [14]

Answer:

Just before the cat drops, it was stationery. Therefore it has energy of position called  potential energy.As it drops, the Gravitational potential energy is converted to Kinetic Energy,The conversion mid- air is P.E to K.E to P.E to K.E to P.E to K.E, until it touches the ground. As it touches the  ground all the energy is converted to P.E energy of position.

As it runs after mouse the P.E is converted back to Kinetic , energy of motion. As it feeds on the mouse , the chemical energy obtained  as protein from mouse meat.This is later converted back to Mechanical energy as (kinetic and Potential  energy)   in the cat.

Explanation:

4 0
2 years ago
Read 2 more answers
Other questions:
  • Saki went on vacation and was fortunate enough to get to see the aurora australis. What solar activity did she observe? solar fl
    14·2 answers
  • How does the chance of a coin landing on each side compare to the chance that a gamete cell will receive a particular gene at me
    10·2 answers
  • Which of the following statements correctly explains a wave in the open ocean?
    10·2 answers
  • Leonard designed a parallel circuit to light two lightbulbs. But his circuit doesn’t work. Which two items in the circuit must b
    12·1 answer
  • a group of scientists decide to post their results on the internet instead of publishing in a scientific journal. what part of t
    11·2 answers
  • Which objects are used in modern mapmaking? Check all that apply.
    13·2 answers
  • When Thomas Hunt Morgan crossed his red-eyed F1 generation flies to each other, the F2 generation included both red- and white-e
    6·1 answer
  • The Phoenix area of the Southwestern desert typically receives 8 inches of precipitation yearly, in two seasonal patterns. Even
    11·2 answers
  • Which statement describe a pattern shown in the data?
    8·2 answers
  • You and your lab partner are looking at a sample of pond water under a microscope. Which statements are TRUE about what you see?
    10·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!