AP Biology Midterm

The fact that ice floats on liquid water is due to the fact that water's solid is ___________ than it's liquid form

less dense

Which statement best help explains the formation of the hydrogen bond presented in the figure?

The nitrogen has a partial negative charge, and the hydrogen attached to the oxygen has a partial positive charge.

Why does ice float?

As water freezes, it expands and its density decreases.

Capillary action is the result of adhesion. Which aspect of water is responsible for this?

Hydrogen bonds between water and another substance

Water is polar because...

The unequal sharing of electrons gives the water molecule a slight negative charge near its oxygen atom and a slight positive charge near its hydrogen atoms.

Why can water have no net charge but have slight charges in different parts of the molecule?

The oxygen end is slightly negative and the hydrogen end is slightly positive.

Figure 1 is a diagram of water molecules at the air-water interface at the surface of a pond.

Hydrogen bonds between molecules at the surface of the water provide surface tension, which allows the water surface to deform but not break under the insect.

What property of water helps to moderate earth's temperature?

specific heat capacity

Attractions between water molecules are called

Hydrogen bonds

Large bodies of water do not quickly fluctuate in temperature. Why?

Water has a high heat capacity.

Like complex carbohydrates, proteins are biomolecules that serve many functions and can be chemically broken down and restructured. Both proteins and complex carbohydrates are which of the following?

polymers of smaller subunits

The molecule below is a

B and C (Lipid and Steroid)

One function of lipids is to store energy. What is another function of lipids in the human body?

to form plasma membranes

Each of these represents a different biomolecule. Which of the following is a carbohydrate?

C

Which statement is the most accurate description of the reaction shown in Figure 1?

It represents a polypeptide chain that is broken down through a hydrolysis reaction.

A disaccharide is formed when two monosaccarides are joined together by

Dehydration synthesis

Which of the following best describes a structural difference between DNA and RNA?

The backbone of DNA contains deoxyribose, whereas the backbone of RNA contains ribose.

Which of the following statements about glucose, galactose, and fructose is most likely true?

The carbohydrates have different properties because they have different arrangements of carbon, hydrogen, and oxygen atoms.

The main source of energy for a cell is

Carbohydrates

Which of the following is an accurate description of the process shown in Figure 1?

The formation of a covalent peptide bond in a dehydration synthesis reaction

Which of the following best describes the hydrolysis of carbohydrates?

The addition of a water molecule breaks a covalent bond between sugar monomers.

One function of lipids is to store energy. What is another function of lipids in the human body?

to form plasma membranes

Which of the following is most directly responsible for water’s unique properties?

It forms hydrogen bonds

Which of the following best describes how the properties of water enable an insect to walk on the waters surface?

Hydrogen bonds between molecules at the surface of the water provide surface tension, which allows the water surface to deform but not break under the insect.

Which of the following is responsible for the cohesive property of water?

Hydrogen bonds between the oxygen atoms of two adjacent water molecules

Which of the following does not represent a correct monomer/polymer pairing?

Triglyceride/cellulose

Which of the following is a true statement?

Both prokaryotic and eukaryotic cells have ribosomes

All of the following statements about chloroplasts and mitochondria are true EXCEPT

Both capture light energy

All eukaryotic cells contain at least one Golgi complex, typically located in the cytoplasm and near the endoplasmic reticulum.

Which of the following best describes a process that occurs within the Golgi complex?

Enzymatic modification of newly synthesized integral membrane proteins

Which of the following produces ribosomes?

Nucleuolus

Which of the following claims is scientifically accurate and consistent with an observation that a decrease in lysosome production within a cell leads to a decline in mitochondrial activity?

Fewer lysosomes will be available to break down macromolecules to provide the necessary nutrients for cellular respiration.

Cells contain smaller components called organelles that are necessary for a cell’s survival. Organelle functions have often been compared to components of larger systems.

Which of the following explains a functional differences between the rough and smooth ER

Rough ER can synthesize and package proteins for export, and smooth ER cannot.

Lysosomes-

Are clean up crews of the cell

The pancreas secretes the hormone insulin, which is a protein.  It would be predicted that these cells would have an abundance of

Rough ER

The death signal inactivates ced-9 and triggers programmed cell death.  What is this called?

Apoptosis

What's the name of the signaling molecule that triggers a transduction pathway?

Ligand

Which of the following involves signaling in the nervous system where electrical signals along nerve cells trigger the secretion of neurotransmitter molecules?

Synaptic signaling

Which of the following types of signaling involves the secretion of hormones by cells?

Endocrine Signaling

Which of the following is a type of long-distance signaling?

Endocrine Signaling

Protein kinases activate other relay proteins by adding a(n) ____ to them.

Phosphate

What is the name of the molecule used in signal transduction pathways that readily diffuse and broadcast signals quickly?

Secondary messengers

What is the name of the pathway that occurs when a signal is received and then converted into a cellular response?

Signal transduction pathway

What type of transmembrane receptor is being shown?

G-protein receptor

Most hormones are proteins. Which other molecule type can serve as hormone?

Lipids

What type of feedback loop is shown?

Positive

Air is less dense at very high elevations, so less oxygen is available than in the denser air at sea level. Based on the model in Figure 1, if a person travels from sea level to a high elevation location, which of the following correctly predicts the response to the decreased blood oxygen level?

More erythropoietin will be secreted from the kidneys, increasing production of erythrocytes.

The coagulation cascade controls blood clot formation in response to blood vessel injury. Thrombin is an enzyme that plays a key role in regulating the coagulation cascade. A simplified model of thrombin’s role in regulating the coagulation cascade is represented in Figure 1. Argatroban is a competitive inhibitor of thrombin.

Which of the following effects on the coagulation cascade is most likely to result from inhibiting thrombin activity with argatroban?

The rate of fibrin formation will decrease.

Identify the stimulus that restores homeostasis.

Scenario: A person begins to exercise which causes their body temperature to increase. The temperature change is noticed (sensed) and the person begins to sweat and their body temperature decreases.

body temperature decreases

Which of the following describes homeostasis?

organism's ability to maintain steady(stable) internal conditions

What kind of cells are made in Meiosis?

Haploid Gametes

A human somatic cell usually has how many chromosomes?

46

When an area of a chromatid is exchanged with the matching area on a chromatid of its homologous chromosome, _________________ occurs

Crossing over

Why is meiosis necessary?

A reduction division of chromosomes of sex cells

The result of meiosis is

4 haploid cells

The chromosomes that pair up during meiosis are called homologous chromosomes

True

What makes this individual's karyotype not normal?

An extra autosome

Both mitosis and meiosis begin with a parent cell that is diploid. Which of the following best describes how mitosis and meiosis result in daughter cells with different numbers of chromosomes?

Mitosis produces two identical diploid daughter cells after one round of division. Meiosis produces four haploid daughter cells after two rounds of division.

Saccharomyces cerevisiae is a diploid yeast species that can reproduce either sexually or asexually. An experiment was performed to induce mitotically dividing S. cerevisiae cells in G2G2 to undergo meiosis. Which of the following best describes the steps these cells will follow to form gametes?

The first division will reduce the number of chromosomes by half for each daughter cell, and the second division will move single chromatids to each daughter cell.

True

Meiosis is the process of

Reduction

Which of the following sequences represents the conduction pathway through the motor neuron shown in the diagram above?

2-1-3-5

If an original cell had a diploid number of 24, how many chromosomes would be present in each resultant cell after meiosis?

12

Which of the following presents a correct interpretation of the changes in chromosome number depicted in Figure 1?

Chromosomes enter metaphase containing two chromatids attached by a centromere. During anaphase, the chromatids are separated, each becoming a chromosome. Cytokinesis distributes the chromosomes into two separate cells.

Which of the following steps in a signaling pathway typically occurs first once a chemical messenger reaches a target cell?

A ligand binds to the receptor.

During a fight-or-flight response, epinephrine is released into the body’s circulatory system and transported throughout the body. Some cells exhibit a response to the epinephrine while other cells do not.

Which of the following justifies the claim that differences in components of cell signaling pathways explain the different responses to epinephrine?

Cell signaling depends on the ability to detect a signal molecule. Not all cells have receptors for epinephrine. Only cells with such receptors are capable of responding.

Which statement best predicts why a cell’s progression through the cell cycle might be halted at the G1/S checkpoint?

There are not enough nucleotides available to construct new DNA.

During meiosis, chromosome number

Divides in half.

What is the apporpriate name for this karyotype?

47-XX- +16

Though the stages of meiosis have the same names as the stages of mitosis, they exhibit fundamental differences. Compare and contrast the two processes to accurately state their main differences.

Meiosis differs from mitosis in that the number of chromosomes is halved and genetic variation is introduced in meiosis, but not in mitosis.

Which three processes lead to variation among offspring that have the same two parents?

crossing over, random chromosome assortment, genetic recombination

The secretion of hormones by the pituitary gland is an example of which type of signaling?

Endocrine signaling

An antigen can induce an immune response in a host organism. Antigens are targeted by antibodies that are produced by the organism’s immune system in response to contact with the antigen. Antibodies are specific to antigens. Many different cell types are involved in immune responses.

Which of the following best explains the role of cell-to-cell communication during a response to an invasion of antigens?

Chemicals that are secreted from antigen-presenting cells then activate helper T cells.

In Meiosis, cells undergo a proccess of reduction divsion to create genetically unique daughter cells, used in fertilization, that increas genetic variation.

True

A hydrophilic peptide hormone is produced in the anterior pituitary gland located at the base of the brain. The hormone targets specific cells in many parts of the body.

Which of the following best explains a possible mechanism that would enable the hormone to efficiently reach all of the target cells in the body?

The hormone is released into the bloodstream where it can be transported to all cells with the correct receptors.

Select all terms that are related to  the diagram above

Gametes, Fertilization, Zygote, Sexual Reproduction

Read the scenario, then select what the body will need to regulate, and what type of feedback will occur:

Scenario:

A butcher slices his finger on a blade. He wraps it in a towel until the bleeding begins to subside.

Wound healing positive feedback

Read the scenario, then select what the body will need to regulate, and what type of feedback will occur:

Scenario:

In the events leading to childbirth the stretching of the uterus triggers a release of oxytocin. Eventually the baby’s head pressing against the cervix triggers more oxytocin until the mother is in full labor.

Labor & delivery positive feedback

For sexually reproducing diploid parent cells, which of the following statements best explains the production of haploid cells that occurs in meiosis but not in mitosis?

Separation of chromatids occurs once, and there are two rounds of cell division in meiosis.

Based on Figure 1, which of the following questions could best be addressed?

Does synapsis of homologous chromosomes in the parent cell contribute to an increase in genetic diversity in the daughter cells?

The insulin receptor is a transmembrane protein that plays a role in the regulation of glucose homeostasis. The receptor’s extracellular domain binds specifically to the peptide hormone insulin. The receptor’s intracellular domain interacts with cellular factors. The binding of insulin to the receptor stimulates a signal transduction pathway that results in the subcellular translocation of GLUT4GLUT4, a glucose transport protein that is stored in vesicles inside the cell. A simplified model of the insulin receptor–signaling pathway is shown in Figure 1.

Which of the following statements best predicts the effect of a loss of function of the insulin receptor’s intracellular domain?

The storage of GLUT4 in vesicles inside the cell will increase.