Explain in detail the mechanism of breathing.Discuss briefly about respiration and acid base balance. Discuss briefly about the structural layers of alimentary tube.

What ecology theories are present in Aldo Leopold's A Sand County Almanac in chapters 1-6?

Each year in late January comes a thaw. The hibernating skunk rouses and walks through the snow, leaving a track behind him. Aldo Leopold, author and speaker, follows the track, wondering about the skunk's purpose and destination. There is time for such musings in January.

Following the skunk track Leopold notices more signs of animal activity as a result of the thaw. A mouse runs across the skunk track. The thaw has exposed its network of tunnels beneath the snow. A hawk dives from the sky for prey, "well aware that snow melts in order that hawks may again catch mice." Rabbits run more freely, giving owls opportunities to feed.

The skunk track ends at a pile of driftwood, so Leopold goes home again.

According to Leopold, among the benefits of owning a farm is a greater understanding of where food and heat come from. Using the example of a felled oak used as fuel for the fire, he examines the origin of the energy in the wood and the process that led to its being used to provide warmth.

This particular oak had reached a diameter of 30 inches, made up of 80 rings. This dates the first ring to the end of the Civil War. The heat generated by burning the wood is, then, "eighty years of June sun." And this heat is greatly appreciated by Leopold's dog.

The oak had been struck and killed by lightning in a summer storm. Leopold felled it, imagining that the "saw was biting its way, stroke by stroke, decade by decade, into the chronology of a lifetime, written in concentric annual rings of good oak." He thinks of the oak over the years as he saws, imagining backward in time through the Great Depression, years of changes to conservation laws, and other significant dates in Wisconsin's conservation and forestry history. He also describes the function of the saw, wedge, and axe—tools for cutting up wood—not only as they relate just to cutting the tree but also how they interact with and reveal the years represented by the rings.

The return of geese in March means spring has truly and fully come. Other animals—cardinals and chipmunks—do not migrate, so they can be mistaken about the coming of spring. But geese migrate, so there is no room for error in timing. The return of hundreds of geese to the marsh on Leopold's property is a sure sign that the season is changing. The geese show their presence and eat last year's corn from fields that have been hidden under snow all winter.

Leopold notes some of the geese are "singles—lone geese that do much flying about and much talking." After careful observation he concludes these are "bereaved survivors of the winter's shooting, searching in vain for their kin." Leopold describes the noise of the birds in the marsh as a robust and boisterous conversation that, by May when the geese have migrated on, becomes much quieter. Through the migration of the geese, Leopold notes, the leftover corn from Illinois is transformed under the Arctic June sun into goslings.

Come High Water

Because of melting snow and the farm's proximity to the river, April often brings flooding to Leopold's farm. This causes both humans and animals to be stranded on high areas surrounded by fields rapidly being transformed into lakes. The geese struggle to find a place to land and feed, while the carp enjoy their larger world. Random pieces of lumber float down the river from areas upriver. Over the years these have been collected in a lumber pile that is "an anthology of human strivings in upriver farms and forests."

Draba

The tiny white blossoms of the Draba flower can go unnoticed by those who are not looking for them. It is a humble and overlooked flower that thrives in sand that is too poor for other flowers. Draba is not a romantic flower, but it does its "small job quickly and well."

Bur Oak

Because of its thick bark the bur oak is the only Wisconsin tree that can survive a prairie fire: "Bur oaks were the shock troops sent by the invading forest to storm the prairie; fire is what they had to fight." Botanists can use pollen embedded in the wood of trees to track the expansion and contraction of the Wisconsin forest over the course of this long battle between forest and prairie. Because of "allies"—rabbits, mice, squirrels, June beetles—that helped both the prairie and the forest, "the net outcome of the battle was a draw." That is, until human settlers intervened in the battle. Settlers plowed fields so that prairie fires were less common. This gave oaks an advantage as more of their seedlings could survive. This allowed much of the land that was prairie to be transformed into thick oak forest.

Sky Dance

In April and May the "sky dance" occurs at dusk and dawn over the woods of the Leopold farm. "Showtime" changes over the weeks as the times of sunrise and sunset change. At the appointed time the male woodcock bird appears and begins to perform a song and dance designed to appeal to his "lady." He spirals into the sky and swoops down for an hour or more, his "dance" accompanied by his unique call. Despite Leopold's careful observation of this sky dance he has many unanswered questions about it, such as where the female is during this dance and the exact mechanism of the music.

When dandelions begin to bloom in Wisconsin, one can listen for the "final proof of spring"—the song of the upland plover, which migrates far to the Argentine during the winter. The plover can be seen flying overhead or alighting gracefully on fence posts. Over the next several weeks the hens nest; the chicks hatch out and grow quickly; by August the chicks have learned to fly.

The plover has adapted well to the changes human agriculture has wrought on the landscape—it lives as easily among cows and farmland as among buffalo and prairie. They have also benefitted from federal migratory bird laws that protect them from hunters.

The Alder Fork—A Fishing Idyl

In this episode Leopold fishes for trout in a stream but has little luck. He relocates his fishing efforts to the Alder Fork—a part of the stream nearer the headwaters. While catching trout, Leopold sits on a rock and considers how much humans are like fish: "ready, nay eager, to seize upon whatever new thing some wind of circumstance shakes down upon the river of time!" He notes that this haste may sometimes have bad effects, but a life devoid of this eagerness would be very dull. Prudence may often be a virtue, but a life wholly prudent is boring. In fact, he remarks: "No prudent man is a fisherman."

1. Sex determination in Mammals. You have identified a gene that you have named “mont1” (for ‘make ovaries not testes’) that is expressed at the time when the bipotential gonad becomes specified to become an ovary. Because of this “show it” evidence that mont1 is expressed in the right place at the right time, you hypothesize that mont1 is a critical regulator of the female primary sex determination pathway to specify ovary development.
   1. From what you know about the primary sex determination pathway for ovary development, what signaling pathway would you predict may activate mont1 expression?
   2. What “lose it” experiment could you do to determine if mont1 is necessary for ovary development. Briefly describe the expected result. (As in … I would do X experiment and expect to see Y result if mont1 is necessary for ovary development).
   3. What “move it” experiment could you do to determine if mont1 is sufficient for ovary development. Briefly describe the expected result. (As in … I would do X experiment and expect to see Y result if mont1 is sufficient for ovary development).

2. Various enteric bacteria, especially E. coli, are the cause of most urinary tract infections in humans. A quick test for the presence of these bacteria in urine is to detect nitrite in the urine. Why?

Whales communicate with one another using sound. What are the benefits of using sound to communicate underwater? What are the costs?

You want to use Cre/loxP system for targeted gene expression instead of knock-out. Briefly describe how this can be accomplished. (3-4 sentences)

1.

A diploid yeast cell (2n = 32) undergoes meiosis. What will be the resulting products?

Group of answer choices

Two diploid cells with 32 chromosomes each

Four diploid cells with 32 chromosomes each

Two haploid cells with 16 chromosomes each

Four haploid cells with 16 chromosomes each

2.

In humans, sex determination involves what mechanism?

Group of answer choices

An X-chromosome mechanism

A Y-chromosome mechanism

An autosomal genic mechanism

It is currently unknown the mechanism that determine biological sex in human

One the main differences between innate and adaptive defenses is that__________.

A) innate defense does not produce memory cells and adaptive defense produces memory cells

B) innate defense is triggered by antigens and adaptive defense responds to changes in the environment

C) innate defense is capable of generating memory cells and adaptive is not

D) innate defense produces antibodies and adaptive defense produces cytokines

1. the number of new virions released from each bacterium host cell represent the _______.

2. "phage" attacks and multiple in __________.

Briefly summarize the processes of mitosis and meiosis indicating where the similarities lie and in which aspects they differ. Explain what is meant by the term ‘linked genes’ with respect to homologous recombination. Identify the different types of chromosomal abnormalities that can lead to disease (e.g. insertions) and in a sentence or two, describe a disorder associated with one of these aberrations. Please use your own words, thanks

describe how anatomy and physiology can be used for many different applications.

Steve independently transformed lentil with either the pea Rms3 or the Rms4 genes, both of which are candidates for increasing lentil leaf size. Describe how he should first test his transgenic lines and then how he should intercross and select for plants that were homozygous for both Rms3 and Rms4.

describe the metabolic process of the bacteria that is used during cheese making, indicating the type of respiration that is happening during the process and the chemical reactions necessary for the formation of lactic acid in great detail. Please use your own words, thanks

briefly describe (one or two paragraphs) the process of somatic cell nuclear transfer and how it is used to create cloned cells.

Explain what you consider to be the positive and negative aspects of cloning both scientifically and morally, giving at least three ‘for’ and three ‘against’ points – Discuss whether you think it is a good use of science and will benefit mankind or whether you believe it is unethical and should no longer be pursued? Please use your own words