DAT Booster Biology Practice Exam 6

Question 1

A botanist has discovered a new plant and notes that it is predominantly found in its gametophyte form. Which category does this plant most likely belong to?

Answer 1

bryophyte

Question 2

All land plants undergo reproduction with an

Answer 2

alternation of generations

Question 3

alternation of generations scheme

Answer 3

alternates between sexual and asexual reproduction stages

Question 4

tracheophytes (including seedless tracheophytes, and seeded angiosperms, and gymnosperms) are found most prominently in the

Answer 4

diploid sporophyte phase

Question 5

bryophytes are found most prominently in their

Answer 5

gametophyte phase

Question 6

The endosperm is not a plant, but rather a specific type of supportive tissue that

Answer 6

provides nutrition to the developing embryo.

Question 7

Double fertilization

Answer 7

found in most angiosperms and results when two sperm from a pollen grain fertilizes one polar nuclei, a degenerate egg.

main egg that is fertilized by a single sperm goes on to form the diploid zygote.

Question 8

seedless tracheophytes have

Answer 8

vascular structures, and it should be noted that plants that have a dominant gametophyte generation will lack true vascular structure.

Question 9

In the fetal circulatory system, the ductus venosus allows blood to bypass which of the following?

Answer 9

liver

Question 10

As oxygenated and nutrient-rich blood returns to the fetus from the placenta via the umbilical vein, half enters the

Answer 10

ductus venosus.

bypasses the liver as blood returns to the heart. The liver in adults acts to filter and detoxify the blood but is not fully functional during early development.

Question 11

Which of the following would be the most immediate consequence of a defective sperm without an acrosome reaching the egg for fertilization?

Answer 11

inability to penetrate zona pellucida

Question 12

acrosome

Answer 12

the head of the sperm and it contains hydrolytic enzymes that allow sperm to digest through the zona pellucida to get to the oocyte.

a mutation in the acrosomal vesicle would prevent sperm from penetrating the zona pellucida in order to reach an oocyte, fuse cell bodies and share its genetic material.

Question 13

IgA

Answer 13

found in mucous, saliva, and breast milk

dimer consisting of two subunits

protects against pathogens

Question 14

IgD

Answer 14

part of the B cell receptor

activates basophils and mast cells

Question 15

IgE

Answer 15

protects against parasitic worms

responsible for allergic reactions

Question 16

IgG

Answer 16

secreted by plasma cells in the blood

able to cross the placenta into the fetus

Question 17

IgM

Answer 17

may be attached to the surface of a B cell or secreted into the blood

pentamer consisting of five subunits.

responsible for early stages of immunity

Question 18

What process immediately follows the penetration of the corona radiata by sperm?

Answer 18

Acrosomal reaction

Question 19

After a sperm penetrates an egg’s outer corona radiata layer

Answer 19

the sperm binds to the ZP3 protein of the zona pellucida to enable mutual recognition of species-compatible gametes.

This binding to the ZP3 protein enables the acrosomal reaction to occur and initiates the start of fertilization.

The release of acrosomal digestive enzymes allows the sperm to further penetrate the zona pellucida to fuse with the egg’s plasma membrane to deposit its nucleus into the egg.

same time the sperm binds to ZP3, the fast block of polyspermy occurs to trigger an influx of Na+ that prevents additional sperm from binding to ZP3

Question 20

Capacitation

Answer 20

capacitation occurs while the egg is in the uterus due to uterine chemicals.

This process increases the permeability of the acrosome and increases the activity of the flagella before the sperm reaches the egg.

Question 21

Once implantation occurs, the placenta starts secreting

Answer 21

human chorionic gonadotrophin (hCG)

Question 22

human chorionic gonadotrophin (hCG)

Answer 22

maintains the corpus luteum.

Question 23

corpus luteum secretes

Answer 23

estrogen and progesterone

Question 24

when implantation does not occur,

Answer 24

the corpus luteum degenerates and as estrogen and progesterone levels drop, the endometrium is shed as menstrual flow.

Question 25

estrogen and progesterone are needed to maintain the

Answer 25

endometrium

Question 26

an LH spike is required

Answer 26

for ovulation

Question 27

Archenteron

Answer 27

archenteron is a primitive digestive cavity of the embryo at the gastrula stage of development in animals. formed by the invagination of mesoderm and endoderm cells, opens to the outside by a blastopore, and finally develops into the gut cavity.

Question 28

operon

Answer 28

set of structural and regulatory genes controlled by a promoter and an operator.

Question 29

Lac Operon in E. coli controls the breakdown of

Answer 29

lactose

Question 30

Three structural genes, ___ ___ ____, code for enzyme involved in lactose digestion

Answer 30

Lac Z, Y, A

Question 31

When lactose is available, LacZ turns

Answer 31

lactose into allolactose, which binds to the repressor and inactivates it, allowing RNA polymerase to attach and transcribe the genes. enzymes for lactose breakdown are only produced when lactose is actually available.

Question 32

A woman using human chorionic gonadotropin during fertility treatment would expect to see stimulated production of which hormone as a direct result?

Answer 32

progesterone

Question 33

A woman undergoing fertility treatment would expect to see increased production of estrogen and progesterone because of

Answer 33

using human chorionic gonadotropic (HCG).

Question 34

Allopatric speciation is best described as which of the following?

Answer 34

Speciation that occurs after a population is divided geographically

Question 35

Speciation that occurs without the presence of a geographic barrier

Answer 35

sympatric speciation

Question 36

In response to low blood glucose levels, __________,

Answer 36

ACTH is released by the anterior pituitary

Question 37

In response to low blood glucose levels, alpha cells of the pancreas in the islets of Langerhans secrete

Answer 37

glucagon into the bloodstream increases blood glucose concentration by stimulating the breakdown of liver glycogen stores (glycogenolysis) and forming glucose from lactic acid and certain amino acids (gluconeogenesis)

Question 38

he hypothalamus secretes CRH (corticotropin-releasing hormone) into the anterior pituitary, causing it to produce and secrete

Answer 38

ACTH (adrenocorticotropic hormone) into the bloodstream.

Question 39

ACTH acts to increase the production of

Answer 39

glucocorticoids such as cortisol by the adrenal cortex, stimulating gluconeogenesis.

Question 40

hGH increases the production of

Answer 40

IGFs (insulin-like growth factors) and stimulates glycogenolysis.

Question 41

Which structure is the precursor for the androgens, estrogens, and progesterone molecules necessary for sexual development?

Answer 41

cholesterol

Question 42

The sex hormones are part of a category of cholesterol-derived hormones known as

Answer 42

steroids.

Question 43

What is an agent that is made and released in response to viruses?

Answer 43

interferon

Question 44

Interleukins

Answer 44

interleukins are cytokines that regulate inflammatory and immune responses and are known to have antitumor properties.

Question 45

All of the following are produced during glycolysis EXCEPT one. Which one is the EXCEPTION? A. Pyruvate B. ATP C. NADH D. ADP E. NAD+

Answer 45

E

Question 46

The development of structures in the appropriate segment along the head-tail axis is regulated by which of the following genes?

Answer 46

HOX

Question 47

HOX genes

Answer 47

responsible for segmentation, by turning on and turning off certain genes in certain segments of the body. affects what anatomic features develop in those segments.

Question 48

The upper limit of action potential frequency is determined by __________.

Answer 48

Absolute refractory period

Question 49

Which organism would be most affected if it were put in a solution with an enzyme that degraded chitin?

Answer 49

Yeast

Question 50

Chitin is a beta-glucose polymer that functions as a structural molecule in

Answer 50

fungal cell walls and arthropod exoskeletons

Question 51

Analogous structures are those resulting from

Answer 51

convergent evolution.

Question 52

Which of the structures below is analogous with a bird’s wing?

Answer 52

Bat wing

Question 53

A segment of DNA reads as follows: 5’ – ATATATGCGCACGC – 3’ What is the corresponding mRNA synthesized?

Answer 53

5’ – GCGUGCGCAUAUAU – 3’

Question 54

Two species of monkeys emerge from a common ancestor. They live in the same jungle and are hunted by the same predators. Both species of monkeys have evolved prehensile tails and increased upper arm strength. Despite their similarities, they are not capable of interbreeding. Which form of evolution has taken place?

Answer 54

parallel

Question 55

Fish gills are able to acquire sufficient oxygen despite being underwater. Why are most fish gills more efficient than land animals with lungs?

Answer 55

countercurrent exchange

Question 56

Miller–Urey experiment

Answer 56

chemical experiment that simulated the conditions thought at the time to be present on early Earth and tested the chemical origin of life under those conditions.

Question 57

Which of the following best describes the role of T-cells in the immune system?

Answer 57

cell mediated response

Question 58

What contains the chromosomal DNA in a bacterium?

Answer 58

nucleoid

Question 59

Which of the following proteins are most likely to be found in the extracellular matrix?

Answer 59

collagen

Question 60

A man with type A+ blood had children with a woman with type AB– blood. All of the following are possible blood types they could have EXCEPT one. Which one is the EXCEPTION?

Answer 60

O+

Question 61

Secondary messengers

Answer 61

molecules that relay signals received at receptors on the cell surface to target molecules in the cytosol and/or nucleus. serve to greatly amplify the strength of the signal.

Question 62

There are 3 major classes of secondary messengers to know for the DAT:

Answer 62

1. Cyclic nucleotides (e.g., cAMP and cGMP) 2. Inositol trisphosphate (IP3) and diacylglycerol (DAG) 3. Calcium ions (Ca2+)

Question 63

The broad use of antibiotics can result in __________.

Answer 63

vitamin deficiency

Question 64

Broad-spectrum antibiotics, such as cephalosporins, are also known to reduce the absorption of

Answer 64

vitamin K in the body

Question 65

During embryologic development, the stage that is best described as a hollow sphere of cells is called a __________.

Answer 65

blastula

Question 66

An experiment on a nerve cell comes to an abrupt end due to an accidental mutation that disables the cell’s Na+/K+ pump. Which of the following would result from the lack of Na+/K+ pump function?

Answer 66

less sodium outside the cell

Question 67

Taiga

Answer 67

taiga biome (also called boreal forest) has cold temperatures and little precipitation, which falls in the form of snow. This biome consists of coniferous forests.

Question 68

Tundra

Answer 68

this biome has very low temperatures with little precipitation. There is very little vegetation as deeper soil is permafrost.

Question 69

Savannas

Answer 69

biome is characterized by high temperatures, precipitation is less than in tropical rainforest. This biome consists of grasslands with scattered trees.

Question 70

Temperate grasslands

Answer 70

this biome receives little precipitation, and as in the name, is temperate.

Question 71

A cancer researcher wants to track a p53 protein related to tumor suppressor functions. Which technique could be used to locate this p53 protein within a cell?

Answer 71

Immunofluorescence staining

Question 72

An E. Coli cell culture is radioactively labelled with sulfur and the cells are then lysed. Where would the radioactive label most likely be found?

Answer 72

proteins

Question 73

Ovulation occurs due to a peak in

Answer 73

LH and FSH levels

Question 74

Which of the following best describes cooperativity?

Answer 74

An enzyme becomes more or less receptive to additional substrate molecules after a substrate binds

Question 75

skeletal muscle

Answer 75

multinucleated cells form syncytium striated and innervated by somatic nervous system

Question 76

Cardiac muscle

Answer 76

striated, but is innervated by the autonomic nervous system. It is mononucleated or binucleated and exhibits properties of a functional syncytium due to its intercalated discs.

Question 77

Smooth muscle

Answer 77

mononucleated but not striated. It does not form a syncytium, and it is innervated by the autonomic and the enteric nervous system.

Question 78

Lobe-finned fish with lungs directly preceded which category of organisms?

Answer 78

amphibians

Question 79

The plasma membrane is predominantly composed of which macromolecules?

Answer 79

Phospholipids and proteins

Question 80

Increasing the amount of cholesterol in a plasma membrane would lead to an increase in _________.

Answer 80

Membrane fluidity at low temperatures

Question 81

A parathyroid tumour, leading to hyperparathyroidism, would cause which of the following symptoms?

Answer 81

Increased bone fractures

Question 82

Which of the following signalling molecule is used in the immune response to stimulate the development and activation of lymphocytes?

Answer 82

interluekin

Question 83

Which of the following plant hormones promote fruit ripening?

Answer 83

ethylene

Question 84

A random group of 200 black bears dissociate from a bigger population and settle in a region 100 km away. It is observed that the smaller group, along with their future generations, have a different fur type than the original population. What best describes this phenomenon?

Answer 84

Founder’s effect

Question 85

bottleneck effect

Answer 85

describes allele frequency change due to catastrophic events

Question 86

Consider a species whose chromosomal count is 2n. A non-disjunction has occurred in meiosis I of spermatogenesis, and the final sperm has fused with a healthy egg. Which of the following CANNOT be the zygotic or gametic genome?

Answer 86

it ended meiosis I with the gametic genotypes n+1 or n-1. Moreover, since it fused with a healthy egg, the final genotype is either 2n+1 or 2n-1. 2n+2 is not a possibility and must be the correct answer.

Question 87

Question #40 A scientist accidentally mixes together bacterial, fungal, and plant cells in a petri dish. He will be able to correctly identify each of these cells by closely examining the composition of their __________.

Answer 87

cell wall