Bio II PlayPosit Answers

What are the two (2) main functions of keeping the stomach highly acidic?

- Activate the enzyme pepsin, which also breaks down proteins - Denature proteins to ease their breakdown

Some lizard species only reproduce by parthenogenesis. What can you infer about this species? Select two that apply

- All the organisms are female - New organisms develop from unfertilized eggs

Photosynthetic protists are very important because: (select all that apply)

- As primary producers, they feed many animals in the food web directly and indirectly - They form symbiosis with organisms such as corals that are fundamental to the ecosystem - They are an important source of O2 and capturing carbon dioxide

What are the advantages of a closed circulatory system? Select two (2) that apply:

- Blood moves at high pressure to the tissues - It can circulate large amounts of oxygen rapidly to a larger body size

Which are the three main adaptations that allowed reptiles to become independent from water?

- Dry skin - Internal fertilization - Amniotic egg

Which of the following adaptations help organisms with a herbivore diet? Select all that apply

- Enlarged foreguts and cecum for fermentation - Multiple chambers that harbor microorganisms that breakdown cellulose - Reprocess food by regurgitation or by eating fecal matter

Which of the following are the two functions of the urinary system? Select two (2):

- Excrete nitrogenous waste (Urea) - Maintain water balance

Fish, frogs and most aquatic animals release their eggs and sperm into the water for fertilization. However, many organisms have evolved internal fertilization. What are the advantages of internal fertilization? Select all that apply

- Fertilization can occur outside of water but inside the organism - It makes it more likely that the eggs and sperm will find each other, requiring the production of fewer gametes - Once inside, the embryo may continue to develop internally

Which of the groups listed on the tree above descended from an ancestral protist but are not considered protists? Select three (3)

- Fungi - Land plants - Animals

Which of the following are present in cnidarians (jellyfish, anemones, corals)? Select all that apply

- Gastrovascular cavity - Tissues - Ectoderm - Endoderm

How is CO2 transported in the blood? Select all that apply

- It dissolves as bicarbonate ion H2C03 decreasing the pH of the blood (more acidic) - It diffuses into the blood's plasma as CO2 - It competes with oxygen for the biding site with hemoglobin

Which are the characteristic of humoral immunity? Select all that apply

- It is carried out by proteins and other chemical substances - Antibiotics are an example of adaptive humoral immunity

Which of the following are true about bilateral symmetry? Select all that apply

- It promoted the organization all sensory organs in the anterior part. - Only a longitudinal cut along the sagittal plane will divide the organisms into two mirror images. - It's advantageous for setting a direction for moving as the organism has an anterior and posterior end.

Which are the characteristic of cell-mediate immunity? Select all that apply

- Macrophages are an example - It is carried out by cells directly

Which of the following animals have a double-loop circulation, complete separation of oxygenated and deoxygenated blood. Select all that apply

- Mammals - Birds

Which of the following organisms secrete hypertonic urine (the urine is hypertonic in relation to the organism's blood). Select all that apply

- Mammals - Birds

Which of the following are examples of mechanisms by which ectotherms regulate body temperature? Select all that apply

- Orient the body towards heat sources to warm up - Spending time in the sun - Moving to areas with lower temperature

What ecological roles can protist have? Select all that apply

- Photosynthesizers - Mutualistic - Predators - Parasitic - Scavengers

Which of the following are synapomorphies (shared derived traits) of mammals? Select all that apply

- Placenta - Endothermy - Mammary glands - Hair

Protists are seen as the bridge between unicellular organisms and multicellular ones. Which of the following support this idea? Select all that apply

- Protists can form colonies with interdependence. - Cells in protistan colonies may have different morphologies and duties.

Despite their multiple adaptations, amphibians are still restricted to moist environments. Which are the three main reasons for that still tie amphibians to water? Select all that apply

- Skin has to keep moist for gas exchange - External fertilization needs water - Eggs have no protection from dehydration

Select all of the following that provide evidence about the support to the Theory of Endosymbiosis.

- The DNA of chloroplasts and mitochondria is very similar to that of other free-living prokaryotes - Chloroplasts and mitochondria are enclosed in a double membrane - Chloroplasts and mitochondria have their own DNA - Chloroplasts and mitochondria divide by a process that closely resembles binary fission

Which of the following variables affects the rate of diffusion? Select all that apply

- The difference in concentration gradient of the gas - The distance between the two sides of gas exchange - The area along which diffusion can occur

Which of the following are the three hypotheses explaining the Cambrian explosion of animal diversity (535-525 million years ago)? Select three

- The evolution of master developmental genes, where mino mutations can cause great changes in the body plan - Increase of oxygen levels in the atmosphere, supporting organisms with larger body size - The origin of predators that can move fast and capture large prey

Which are some of the advantages of bilateral symmetry? Select all that apply

- There is a clear direction for movement with a front and a back - Neurons can concentrate near sensory organs starting the evolution of a brain - Allow the location of sensory organs towards the front of the organism

Most frogs and most aquatic species have external fertilization. Select two (2) disadvantages of external fertilization:

- They depend on water to reproduce - More eggs and sperm have to be produced to enhance chances of fertilization

Which of the following are true about how cnidarians obtain food? Select all that apply

- They do mostly extracellular digestion - They are mostly carnivores, eating other animals

Which of the following are true in regards to how most sponges feed? Select all that apply

- They filter water - They can only eat small particles - They do mostly intracellular digestion

The main function of the small intestine is nutrient absorption. Which of the following structural qualities of the intestine increase absorption? Select all that apply

- Very long tube of almost 6 meters in length when relaxed - Internal wall covered with fingerlike projections called villi - Cell membrane of epithelial cells with multiple foldings

When is sexual reproduction more beneficial than asexual reproduction? Select all that apply

- a species has accumulated numerous deleterious mutations - pathogens are very abundant and are targeting the population - environmental conditions are changing rapidly

Earthworms, tapeworms, snails and other individuals that move slowly and live in small numbers often are hermaphroditic. Select the advantages of hermaphroditism:

- the organism can fertilize themselves if they can't find a mate - when they find a mate, both organisms will have fertilized eggs - when they find a mate, they don't have to worry about being from the opposite sex

Organize the path of blood flowing in mammals: starting with deoxygenated blood located in the right ventricle of the heart, then to pulmonary arteries and then... label 1-5

1 - Lungs 2 - Pulmonary veins 3 - Heart 4 - Systemic arteries 5 - Tissues

Starting at the heart, organize the path of blood flowing in fish from 1-5

1. Arteries 2. Gills 3. Body tissues 4. Veins 5. Back to the heart

Use the numbers 1-5 to sort the following events from oldest (1) to most recent (5), in the sequence of evolution of life on Earth:

1. Origin of bacteria 2. Origin of mitochondria 3. Origin of chloroplasts 4. Origin of multicellular eukaryotes 5. Origin of fungal-plant symbioses

Indicate the order of the following events in the formation of an action potential from 1-5

1. Sodium channels open 2. Sodium rushes into the cell 3. Potassium channels open 4. Potassium rushes out of the cell 5. Refractory period

Sort the order in which the urine passes through the different structures in the nephron from 1-5

??? 5. loop of Henle, 4. bowman's capsule, 2. distal convoluted tube, 1. collecting duct, 3. proximal convoluted tube

Which of the following is the primary mechanism in which endotherms regulate body temperature?

Activate metabolism to increase temperature

The loop of Henle carries urine through the medulla of the kidney, which has a high concentration of salts. How is the hypertonic environment of the kidney's medulla maintained?

Active transport of salts out of urine

Nitrogen waste from the metabolism of proteins has to be discarded. Match the type of by-product with its advantages or disadvantages

Ammonia - highly toxic but easily dissolves in water Urea - low toxicity and highly soluble in water so it can be concentrated Uric acid - low water solubility, conserves water but energetically costly

Match the enzymes with the organ that produces them in the table below

Amylase - pancreas and salivary glands Pepsin - stomach Bile - liver

Match the enzymes with the molecules they help break down in the table below

Amylase - starch Pepsin - proteins Lipase - lipids

What do we call the structures on pathogens that are recognized by the adaptive immune system?

Antigens

Which of the following are true about radial symmetry?

Any longitudinal cut will divide the organism into two mirror images

Which one of these is NOT a component of nonspecific (innate) immunity?

B-cells

Which one of these is involved in adaptive and humoral immunity?

B-cells

Which of the following explains why arteries have thicker walls than veins?

Because arteries carry high pressure blood from the heart

Which of the following structures is intended to maximize the concentration gradient between the two sides of the gas exchange?

Blood circulates in counter current direction to water flow in gills

Which of the following describes a closed circulatory system?

Blood moves from the heart into arteries and into smaller vessels and then back into larger vessels as it makes its way back to the heart

Which direction of blood movement would let you extract more oxygen?

Blood moving in the opposite direction as water

Corals heads are massive colonies started by a single individual that break off and gradually grows into a whole new organism. What is this type of reproduction?

Budding

You discovered a new organism unknown to science. As you are dissecting it, you notice that the digestive track is relatively short with very small or reduced additional chambers. What diet do you hypothesize this organism has?

Carnivore

The ___ NS integrates the information received, coordinates and influences the body's activity. Controls most functions of body and mind. Two parts: the brain and the spinal cord. Brain = center of our thoughts, the interpreter of external environment, and the origin of control over body movement On the other hand, the ___ NS is composed of nerves and ganglia. Main function: connect the Brain and Spinal Cord to the limbs, organs, and body. It relays signals by motor nerves, to tell the body to m

Central Peripheral

Sponges (phylum: Porifera) are animals that possess feeding cells called collar cells. These cells have a central flagellum surrounded by a collar. The collar filters organic matter out of the water column. Which protist shares a more recent common ancestor with the poriferans?

Choanoflagellates

Match the following specific tissues to the type of tissue they are classified as in the table below

Connective tissue - cartilage, blood Epithelial tissue - cells lining the interior of the lungs, surface of the skin Nervous tissue - neurons Muscle tissue - heart muscle

Which of the following cells in responsible for cell-mediated immunity in the adaptive response?

Cytotoxic T-cells

___ transfer information to the cell body, while ___ transfer info from the cell body

Dendrites Axons

Bony fishes appeared to have evolved in freshwater and then recolonized marine environments. As a result, they are hypotonic to seawater. Which adaptations do bony fishes use in seawater?

Drink lots of water and actively excrete ions

Where in this tree was the evolution of limbs?

E. Tetrapoda

Which of these statements applies to organisms with environmental sex determination?

Environmental conditions determine the sex of an individual

Explain how is it possible that the chloroplasts of Euglena (Euglenozoa) and green alga (Chlorophyta) are very similar, yet they don't share a common ancestor who has chloroplasts?

Euglena must have acquired its chloroplasts by secondary endosymbiosis from a green alga

Freshwater has very low concentration of solutes. Thus, most freshwater organisms face:

Excess of water gain as water enters cells by osmosis

Moving and supporting your body weight on land is challenging. Which feature helped arthropods move efficiently in land?

Exoskeleton made of chitin

Match the following trait in birds to the adaptation it provides for flight.

Feathers - light insulation for heat conservation Fused bones - rigid structure to anchor strong muscles for flight Endothermy - ability to maintain high metabolism

Match the circulation path with the animal who has it in the table below

Fish - single-loop circulation, blood passes through heart once before going to tissues Amphibians - double-loop circulation, blood goes through the heart twice but mixes with deoxygenated blood returning from the tissues Mammals - double-loop circulation, complete separation of oxygenated and deoxygenated blood

Which of the following describes an open circulatory system?

Hemolymph moves from the heart into the tissues and cavities and then drains back into the main cavity

You discovered a new fossil of an organisms that had many molars and those molars were very robust, while it had almost no canines. What diet do you think that organism had?

Herbivore

Many hormones affect homeostasis and often there are two hormones with opposite effects. What is the advantage of having two hormones with opposite function?

Homeostasis often requires two separate mechanism with opposing effects to keep set parameters

Which of the following features DOES NOT improve the rate of diffusion?

Inhaled fresh air is mixed with old air from the previous breathing cycle in mammals

Which of the following organisms has an open circulatory system?

Insects

Since life evolved in the sea, most invertebrate organisms are osmoconformers. This means they are:

Isotonic to their environment

What is the main advantage of the amniotic egg?

It allows gas exchange while preventing water loss

The protistan Paulinella is has a photosynthetic plastid called a chromatophore. Chromatophores have a peptidoglycan membrane and their DNA is more closely related to cyanobacteria than to chloroplasts (Fig. 25.18). Based on this information, what is the possible origin of the chromatophore?

It derived from a prokaryote that was engulfed by the ancestor of Paulinella

Which of these statements is true about the evolution of multicellularity in eukaryotes?

It occurred independently multiple times in several eukaryotic lineages

Which one is a characteristic of adaptive immunity?

It's developed upon encountering a pathogen

Which one is a characteristic of innate immunity?

It's inherited and evolutionary ancient

Match the traits to the adaptation to land it provides

Legs - support body weight and provide movement on land Lungs - obtain oxygen from air Internal fertilization - prevent gametes from drying out

Which of the following hormones can activate intracellular receptors?

Lipid soluble hormones such as steroids

Vaccinations are effective in combating future infections because they induce the production of

Memory cells

What is the final destination of the oxygen we breath?

Mitochondria to make ATP

The loop of Henle carries urine through the medulla of the kidney, which has a high concentration of salts. What is the main function of the loop of Henle?

Move water out of urine

Which of the following structures is intended to maximize the surface area available for gas exchange?

Multiple infoldings of respiratory surfaces, such as lamellae in gills and alveoli in lungs

Match the mechanism by which organism keep conditions in dynamic constancy

Negative feedback - A sensor, an integration center and effectors that activates when conditions deviate from a set point Antagonistic effectors - Sensors and effectors that act when conditions deviated in opposite directions from a set point Positive feedback - A feedback loop that amplifies initial changes in the same direction

___ conduct and transmit electrical impulses ___ carrying nutrients, removing waste products, provide support and defense from pathogens for other cells in the nervous system

Neurons Glia cells

Protists are very diverse. Almost any unicellular eukaryote is considered a protest. However, plants, fungi and animals evolved from ancient protists. Based on this phylogeny, could you conclude that protist form a monophyletic group?

No

Which of these statements is TRUE when comparing sexual and asexual reproduction?

Only half of the offspring from sexually reproducing females are also females

Match the following innovations to the digestive system to taxa (group of organisms) where they first appeared in the table below

Porifera - Intracellular digestion Cnidaria - First to have extracellular digestion Nematoda - First to have a complete digestive track with mouth & anus

Match the following organs to the molecules they help breakdown in the table below

Salivary glands - carbohydrates Stomach - proteins Pancreas - carbs, proteins, and lipids

Which is the main advantage of having a coelom body cavity?

Space for complex organ systems

Which of the following are present in sponges?

Specialized cells

As other endotherms, mammals have a great demand for oxygen to sustain their higher metabolic rate. Mammalian lungs are packed with millions of tiny sacs clustered like grapes called alveoli. Which aspect of Fick's law did mammals optimize by having multiple alveoli?

The area along which diffusion can occur

The affinity of hemoglobin for oxygen changes with pH. What is affecting the pH of the blood?

The blood changes its pH based on the amount of carbon dioxide dissolved

Which are come of the advantages of body segmentation?

The body plan can be easily repeated

In most vertebrates air flows in and out through the same air way. However, birds have a system of connected air sacs the allow unidirectional air flow through the lungs making them extremely efficient compared to other vertebrates. Which aspect of gas exchange did birds optimize by having one way air flow?

The difference in concentration gradient of the gas

How can the same hormone have different effects in different organs? For example, epinephrine acts in the liver to increase gluconeogenesis and it acts in the heart to increase heart rate.

The hormone may activate the same receptor type, but each organ will have a different set of internal proteins so a different cellular response is triggered

Water only moves by osmosis, thus the kidney has to create the osmotic conditions to promote water movement in the direction required. How can the kidney produce hypertonic urine?

The kidney has hypertonic regions that make water move out of urine

Hemoglobin binds to oxygen and transports it in the blood. However, this requires hemoglobin to pick up oxygen in the lungs and then release it at the tissues that need it. Besides changes in oxygen concentration, what other mechanism helps ensure this?

The tissues that need oxygen are also producing CO2, which lowers the pH of the blood and makes hemoglobin release even more oxygen

Lipophilic hormones tend to affect gene expression. Based on this you can infer that:

Their effects will be slow but long lasting

Many endocrine disruptors tend to have slow but very long lasting effects. Based on this, what do you think endocrine disruptors are doing?

They are binding hormone-activated transcription factors and thus changing gene expression

Which of the following structures is intended to minimize the distance between the two sides of the gas exchange?

Thin membranes lining respiratory organs such as gills and lungs

Which of the following organisms has a closed circulatory system?

Vertebrates