Why aren't there many large carnivores?

Answer:

Technically, the largest ever marine predator known thus far - the blue whale - is, for now, alive and well, but I know what you mean. You’re not talking about filter-feeders, or fish-eaters, you mean macropredators.

The last truly enormous macropredator in our oceans was probably Carcharocles megalodon, which went extinct about 3.6 million years ago. Other recent examples include the terrifying sperm whale Livyatan melvillei (which disappeared 8.9 mya) and other megatoothed sharks like C. chubutensis.

So, why did the giants go away? The answer, in truth, is likely multi-faceted. Here are some major promising hypotheses, or at least contributing factors:

Whales have declined. Giant sea carnivores like C. megalodon and Livyatan relied on marine mammals - specifically baleen whales. During the Pliocene, the Americas connected and the Central American Seaway was closed. This seems to have triggered a significant decline in the diversity of tropical whales, and would thus limit food availability for huge, energy-hungry predators.

Things got too cold. The extinction of megalodon and other giant ocean predators roughly coincides with the trend of decreasing temperatures the Pliocene brought. Giant sharks in particular, not being fully warm-blooded, would suffer from this, and it would also mean a decline in food supply. You can even see a sudden cold snap just about when Carcharocles went extinct, 3.6 mya.

Smaller predators outcompeted them. The niche of Carcharocles and the macroraptorial sperm whales is arguably still filled today - by the killer whale. Many orca pods specialize in hunting whales or other marine mammals. However, killer whales and their ancestors were perhaps more opportunistic, fast, intelligent and indeed adaptable than the massive, solitary hunters.

Ironically, the largest ever marine predator owes its existence to the demise of the largest ever marine macropredators. Since the extinction of macroraptorial sperm whales and Carcharocles megalodon, baleen whales have been gradually increasing in size, for they no longer need to be as fast and agile. Because of this, we have the privilege of sharing our world with the largest animal known to have ever lived - the blue whale.

A cluster of cases of legionellosis have occurred in your neighborhood. People with the illness have cough, fever, shortness of breath, chest pain and sometimes diarrhea. The illness is caused by the bacterium Legionella pneumophila, a facultative intracellular parasite that survives in certain ameba. The organism has an absolute requirement for L-cysteine. Typically, the organism is grown on buffered charcoal yeast extract (BCYE) agar. In some labs, samples containing suspected L. pneumophila are cultured on traditional BCYE medium as well as BCYE medium lacking L-cysteine. How would L. pneumohila be identified in this situation

Which of these genotypes represents a carrier?
Аа
aa
XXY
AA

19. Fresh poultry should be rejected when:

A. It has been shipped in plastic wrap
B. It is slightly sticky to the touch
C. There is no discoloration
D. The receiving temperature is 38°F

Assume that one backbone of a DNA molecule has the sequence given below. A-T-G-G-G-G-G-C-G-A-T-A-T-T-T-T-A-T-C-C-G-A-C-G For this sequence: give the expected sequence of the other DNA backbone. T-A-C-C-C-C-C-G-C-T-A-T-A-A-A-A-T-A-G-G-C-T-G-C give the RNA sequence transcribed from the original DNA backbone. U-A-C-C-C-C-C-G-C-U-A-T-A-A-A-A-U-A-G-G-C-U-G-C give the Amino Acid sequence of the protein built from the original DNA backbone.

Select all that apply.
Which of the following are true about a block of ice at -10°C as you continue to apply heat.


Its temperature will rise continuously until it completely melts.
Its temperature wil rise until reaching o°C.

Its temperature will not rise above -10°C until it melts. Its

temperature will remain at 0 G until all the ice melts.​

Which of these is an impact of burning coal for energy?
A. acid rain
B. mercury released into the waterways
C. Increased carbon dioxide in the environment
D. all of the above

Emilia Burton is an 18-year-old high school student who began to experience weight loss despite a ravenous appetite and resulting increased dietary intake. She has to make frequent trips to the bathroom to urinate and has difficulty concentrating on her work because of fatigue. She drinks large volumes of coffee to help with a constant dry mouth and to combat her fatigue. At a clinic appointment, it was noted that her weight has dropped from 140 lb to 128 Ib.
a) What is the probable diagnosis of this patient? What information from the above scenario would support your diagnosis?
b) What laboratory test(s) should be performed? Which result(s) would support your diagnosis? What immediate and long-term therapy will Emilia need to manage her disorder?
c) Emilia should be aware of the potential acute and long- term complications of her condition. What are they?

Cellular Respiration and Energy

The mutations responsible for the dark fur color in the Arizona mice were absent from the three different populations of New Mexico mice. No Mc1r mutationswere associated with dark fur color in the New Mexico populations. These findings suggest that adaptive dark coloration has occurred at least twice in the rock pocket mouse and that these similar phenotypic changeshave different genetic bases. How does this study support the concept that natural selection is not random

A scientist is observing a new species of organism. She observes that from generation to generation many of the organisms’ offspring have adaptations that their parents did not have. This organism is most likely reproducing through_______.

a. sexual reproduction
b. budding
c. asexual reproduction
d. binary fission

Which feature of the Earth's surface is caused by wind?
A)
rock quarries
B)
canyons
C)
sand dunes
for
D)
mountains

What practice helps scientists avoid bias in their findings

Which of the following events occurs in DNA replication in prokaryotes?
a. Replication starts from a single point and proceeds in two directions until the entire chromosome is copied.
b. Replication starts from multiple points and proceeds in two directions until the entire chromosome is copied.
c. Regulatory proteins bind to all of the nucleotides on the DNA molecule.
d. Enzymes “unzip” the DNA molecule by breaking ionic bonds between base pairs.

Apply: Suppose a template strand of DNA had the following sequence: T A C G G A T A A C T A C C G G G T A T T C A A What would be the complementary strand of mRNA?

in what parts of the cycle do you think phosphorus spends the most time​

What is AB?
A
12
B.
C
35

Please Help!!!!
Muscles intended for large, powerful contractions contain llx muscle fibers. true or false​

In ancient times, people believed Earth was the center of the Solar System. Which of the following makes the geocentric model impossible?
O The moon revolves around Earth.
O Earth's gravitational force is much less than the Sun's.
o Orbits are elliptical, not circular
There are other planets that are closer to the Sun.

You perform an experiment in which chromatin is isolated from sea urchin sperm cells and briefly digested with micrococcal nuclease. When the chromatin proteins are removed and the resulting purified DNA is analyzed by gel electrophoresis, you observe a series of DNA fragments that are multiples of 260 base pairs in length (that is, 260 bp, 520 bp, 780 bp, and so forth). a) Although these results differ somewhat from the typical results discussed in the chapter, explain why they still point to the likely existence of nucleosomes in this cell type. b) What can you conclude about the amount of DNA that is associated with each nucleosome

PLEASE HELP!!!!
Explain what causes a muscle to go into rigor mortis. Your answer should include the circumstances which cause it, as well as why those circumstances cause the effect (what is happening in the muscle at a molecular level which causes the stiffness). ​

These are carbohydrates -rich vegetables EXCEPT
a. Tubers
b. nuts
c. seeds
d.roots​

Which of the following is not a function of the bacterial cell wall?

A. Provide the cell with shape and rigidity
B. Prevent the cell from lysing
C. Protect the cell
D. Provide the cell with locomotion

How do bacteria multiply again? Use the key terms genetic information, DNA, split in two, and exponential growth.

pls help will give brainliest

The diagram below represents a sample of a sedimentary rock viewed under a
microscope. Which part was formed first?

This equipment can be used for plowing ,planting,cultivating,mowing soil and pulling farm machinery,what is it?​

Determine the rate of oxygen consumption at each temperature for comparison. Then divide the higher rate by the lower rate to obtain the difference (ratio) between the two temperatures. Round your answer to the nearest 0.1. It can be concluded that mouse respiratory rate (increases or decreases) when temperature is lowered. In this experiment there was a fold difference in respiratory rate at the two temperatures.

Where do nutrients enter the body?

Write one scientific question about the organism in
the photo. Sunflowers

describe how you would test a sample of powdered milk to see if it contained protein ​