FISH 270 - Midterm 1 (WIN21)

The process of photosynthesis probably originated ________.

in prokaryotes

When oxygen is released as a result of photosynthesis, it is a direct by-product of ________.

splitting water molecules

What is the main purpose of light-dependent reactions of photosynthesis?

to produce NADPH and ATP

Which of the following is NOT a premise of cell theory: (1) All cells arise from cells (2) All living cells require water (3) All DNA methylations are inherited (4) Natural section acts upon genotypes instead of phenotypes

2,3,4

Biologists sometimes divide living organisms into two groups: autotrophs and heterotrophs. These two groups differ in ________.

Their source of C-C bonds

Why did scientists originally hypothesize that proteolytic enzymes such as pepsin and trypsin are secreted in inactive form?

These proteolytic enzymes, in active form, would digest the very tissues that synthesize them

True or False: During the "cyclic electron flow" electrons excited in Photosystem I are transferred back to the electron transport chain, generating an excess of NADPH which is used in the Calvin cycle to fix more CO2.

False

True or False: In prokaryotes, fermentation is always used as a backup mechanism to obtain energy (2 ATP) in absence of oxygen access.

False

In anaerobic prokaryotes that are obligate fermenters, which biochemical reaction produces more ATP?

Glycolysis

The process of obtaining food is known as ________, and requires specialized mouthparts.

Ingestion

Heat conservation is important for polar endotherms, thus they tend to be _________ so that they __________ their surface area to volume ratios.

Larger; minimize

What limiting factors have the greatest influence on phytoplankton distribution in aquatic biomes?

Light and nutrients

Low pH in the stomach is achieved by what process?

Parietal cells secrete HCl into the lumen of the stomach

Which of the following processes is/are involved in the transgenerational inheritance of epigenetic DNA modification?

Methylation

What can the mouthparts of an animal tell you about its diet?

Mouthparts provide clues about the specific foods an animal pursues

The four main forces of evolution are mutation, gene flow, genetic drift and natural selection. Which of these forces may decrease the genetic diversity in populations?

Mutation and Drift

What type of feedback is involved in thermoregulation?

Negative

In marine prokaryotes, which of the following final electron acceptor provides the greatest energy yield in cellular respiration?

O2

Some animals have no gills when young, but then develop gills that grow larger as the animal grows larger. What is the reason for this increase in gill size?

Relative to their volume, the young have sufficient skin surface area across which they can transport all the oxygen they need

Some authors have found evidences that DNA methylation support phenotypic plasticity in oysters. Based on this, epigenetics is expected to ___________ evolution in these organisms.

Slow down

Pepsinogens need which of the following to function?

acidic environment

In autumn, the leaves of deciduous trees change colors. This is because chlorophyll is degraded and ________. Correct!

carotenoids and other pigments are still present in the leaves