1answer.
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
Vinil7 [7]
3 years ago
5

Over the past 60 years, many amphibian species have experienced significant population declines and some species have become ext

inct. Scientists suspected that local human activities such as the destruction of wetlands, regional pollution, and deforestation were the main reasons for these losses. However, research over the past 20 years reveals significant amphibian population declines in protected areas of the world, such as nature preserves and parks. These global declines suggest widespread problems including increased ultraviolet radiation, acid rain, and disease. In Switzerland, for example, 14 of the 20 native amphibian species are threatened with extinction. Some biologists urge the collection of the few remaining individuals of some of the most threatened amphibian species, to preserve them if they become extinct in the wild. If such captive breeding programs could produce thousands of individuals from just a few of the remaining survivors, the species will still be threatened because of ______.
Biology
1 answer:
ollegr [7]3 years ago
5 0

Answer:

a bottleneck effect

Explanation:

Genetic drift refers to the change in the allele frequencies in a population due to chance (random) events. The bottleneck effect, also known as population bottleneck, can be defined as a severe case of genetic drift caused by a drastic reduction in the population size. The bottleneck effect is well known to cause the loss of important genetic variation since alleles that were present in the original population are lost, thereby limiting its genetic diversity. One of the most common causes that may lead to a population bottleneck in a natural population is environmental disasters (e.g., earthquakes, floods, etc).

You might be interested in
3. The diagram to the right shows a flower.
MArishka [77]

Answer:

A. parts A and B

Explanation:

A is the filament and B is the anther

8 0
3 years ago
which principles states, that in undisturbed rock layers, the oldest rocks are on the bottom and the youngest rocks are on top
Leviafan [203]

Answer:

The correct answer is principle of superimposition.

Explanation:

According to the superimposition principle, in the undisturbed rocks, the youngest rocks are situated on the top and the oldest rocks are found in the bottom. The phenomenon takes place due to withering. The rocks get withered because of the influence of air and water.  

The soil particles or the sediments get gathered at another site. The deposits of sediments get concentrated with time and result in the production of rocks. The mature rocks get surrounded by the layers of sediments with time passing by. These sediments get concentrated again to produce novel rocks. Through this procedure, the fresh young rocks get produced over the older ones.  

3 0
3 years ago
FOR 30 POINTS!!
Kipish [7]

Answer:

1. pulse oximeter

2. spirometer

3. sphygmomanometer

4. stadiometer

5. scale

6. scale + tape measure

7. spirometer

8. pulse oximeter

9. thermometer

Explanation:

8 0
3 years ago
Oxygen, carbon dioxide:
Liula [17]
D because I done that lol
3 0
3 years ago
What is the name of structure [G] in the diagram above?
timurjin [86]

Answer:

Centrosome

Explanation:

Diagram I and are II are single cells. Diagram I is an animal cell, Diagram II is a plant cell (can see the cell wall and the central vacuole).

G is the centrosome. The centrosome is made up of two cylindrical structures called centrioles. They are the microtubule organising centres (MTOCs) in cells. They regulate the assembly of microtubules during the cell cycle

8 0
3 years ago
Other questions:
  • What kind of animals are best suited to life at the north pole? pick one
    11·2 answers
  • WILL GIVE 50 POINTS!!!
    10·2 answers
  • How can meteorologists use the jet stream to predict the weather
    6·2 answers
  • Under what circumstances does membrane transport always require energy?
    10·1 answer
  • What are three practices proven to be effective in lowering the risk of becoming infected with an STI.
    5·1 answer
  • You are the scientific consultant for a television show about forensic analysis. In an upcoming episode, investigators will comp
    15·2 answers
  • Carlos was in a car accident and received a head injury that resulted in a decreased ability to produce speech. carlos has more
    5·1 answer
  • Birds with average-size wings survived a severe storm more successfully than other birds in the same population with longer or s
    11·1 answer
  • Help plzzz I’ll give Top Brainiest
    11·1 answer
  • Which of the following glands does not secrete any hormones?
    13·2 answers
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!