Biology MCQs

Biology MCQs

Answer these 300+ Biology MCQs and see how sharp is your knowledge of Biology. Scroll down and let's start!

1: An embryonic cell that is "totipotent" is one that can _____.

A.   Trophoblast

B.   Cleavage... a cluster of cells

C.   By itself, give rise to the entire embryo, as cleavage proceeds

D.   They have extra-embryonic membranes that develop an aqueous environment in which development occurs

2: At the moment of sperm penetration, human eggs _____.

A.   Have used flagellar propulsion to move from the ovary to the oviduct

B.   Are still located within the ovary

C.   Have a paper-thin cell of calcium carbonate that prevents desiccation

D.   Are still surrounded by follicular cells

3: Birds reptiles and mammals are called amniotes because _____

A.   By itself, give rise to the entire embryo, as cleavage proceeds

B.   They have extra-embryonic membranes that develop an aqueous environment in which development occurs

C.   Cleavage... a cluster of cells

D.   Trophoblast

4: During gastrulation in frogs, a rod of mesoderm under the dorsal surface forms the _____.

A.   Blastopore

B.   Spinal cord

C.   Ectoderm

D.   Notochord

5: In the five-kingdom system, prokaryotes are placed in the kingdom _____.

A.   Protista

B.   Reflects evolutionary history

C.   They are sedentary.

D.   Monera

6: The domain eukarya contain(s) ______ kingdom(s).

A.   One.

B.   Two

C.   Three.

D.   Four.

7: The mesoderm gives rise to _____

A.   Skeletal and muscular systems

B.   Cleavage ... a cluster of cells

C.   The membrane of the egg depolarizing

D.   The allantois helps form the umbilical cord in human development.

8: The notochord functions as a core around which mesodermal cells form the frog's _____.

A.   Backbone.

B.   Ectoderm

C.   Blastula

D.   Archenteron

E.   Blastopore

9: The outer-to-inner sequence of tissue layers in a post-gastrulation vertebrate embryo is _____.

A.   Endoderm → ectoderm → mesoderm.

B.   Mesoderm → endoderm → ectoderm.

C.   Ectoderm → mesoderm → endoderm.

D.   Ectoderm → endoderm → mesoderm.

10: The primitive streak in a bird is the functional equivalent of _____.

A.   The blastopore in the frog

B.   The archenteron in a frog.

C.   Polar bodies in a sea .

D.   None of these

11: The term polytomy refers to a situation in which __________.

A.   A branch point within a phylogenetic tree represents the most recent common ancestor

B.   None of the listed assumptions should be made

C.   Trees should not be used to indicate absolute age unless specifically mentioned to scale

D.   Taxons do not evolve from the taxon they are adjacent to

12: The three most abundant classes of nutrients are __________.

A.   Carbohydrates, proteins, and minerals

B.   Fats, proteins, and carbohydrates

C.   Proteins, nucleic acids, and carbohydrates

D.   Triglycerides, starches, and proteins

E.   Proteins, fats, and minerals

13: Almost all animals except _____ have either radial or bilateral symmetry.

A.   Sponges

B.   Tunicates

C.   Clams

D.   Insects

14: Early work on signal transduction and glycogen metabolism by sutherland indicated that __________.

A.   The signal molecule combined directly with a cytosolic enzyme to form an active quaternary structure

B.   The signal molecule worked equally well with intact or disrupted cells

C.   The signal molecule did not interact directly with the cytosolic enzyme, but required an intact plasma membrane before the enzyme could be activated

D.   The cell-signaling pathway involves two separate steps: transduction and response

E.   Epinephrine is involved in response to stress

15: The decidua basalis is ________.

A.   Destined to remain in the uterus after the birth of the infant

B.   Located between the developing embryo and the myometrium

C.   Not a maternal contribution to the placenta

D.   The tissue that surrounds the uterine cavity face of the implanted embryo

16: When bapna is hydrolyzed, it _______.

A.   Complexes with starch

B.   Changes from colorless to yellow

C.   Changes from yellow in color to colorless

D.   Produces reducing sugar

17: A blastomere is a _____ and a blastocyst is _____.

A.   Hollow ball of cells; a cell resulting from cleavage

B.   Fetal organ produced by cleavage; an embryonic organ produced by cleavage

C.   Fetal membrane; an embryonic membrane

D.   Cell produced by cleavage; a hollow ball of cells

18: As cleavage continues, a zygote forms into a solid multicellular ball called a(n) _____.

A.   Morula

B.   Gastrula

C.   Blastula

D.   Ectoderm

19: Cleavage as part of embryonic development is distinctive because it involves ________.

A.   Cell division by mitosis with little or no growth between successive divisions

B.   The fusion of gametes

C.   Splitting the cell into two separate cells

D.   Meiosis

20: Examine the evolutionary tree below. this tree tells us that the amnion is found in ______.

A.   Genetics and evolutionary biology

B.   Lungfishes and amphibians

C.   Plante and fungi

D.   Mammals, lizards, snakes, crocodiles, and birds

21: In a comparison of birds and mammals, having four limbs is _____.

A.   A shared ancestral character

B.   A shared derived character

C.   A character useful for distinguishing birds from mammals

D.   An example of analogy rather than homology

22: In a newly fertilized egg, the vitelline layer _____.

A.   Lifts away from the egg and hardens to form a fertilization envelope

B.   Secretes hormones that enhance steroidogenesis by the ovary

C.   Reduces the loss of water from the egg and prevents desiccation

D.   Provides most of the nutrients used by the zygote

23: In fetal circulation the descending aorta carries the less oxygenated blood from the _________.

A.   Ductus arteriosus.

B.   Positive feedback control

C.   Antibodies from the mother's immune system.

D.   None of these

24: The first stage of embryonic development is _____. this process produces _____.

A.   Gastrulation ... a three-layered embryo

B.   Ovulation ... a zygote

C.   Cleavage ... a cluster of cells

D.   Neurulation...a neurula

E.   Parturition ... a fetus

25: Feedlots are a major cause of _________ in water.

A.   The clean water act.

B.   Point source polluters.

C.   Bioremediation.

D.   All of these choices are correct

26: According to the fossil record, plants colonized terrestrial habitats ________.

A.   In conjunction with insects that pollinated them

B.   In conjunction with fungi that helped provide them with nutrients from the soil

C.   To escape abundant herbivores in the oceans

D.   Only about 150 million years ago

27: The behavior of an infant in sensorimotor stage four might best be described as _____.

A.   Goal oriented

B.   Redundant

C.   Stubborn

D.   Unintentional nhinnta anntinue

E.   Deliberate

28: The primary difference between enhancers and promoter-proximal elements is that enhancers _____.

A.   Are transcription factors; promoter-proximal elements are DNA sequences

B.   Enhance transcription; promoter-proximal elements inhibit transcription

C.   Are at considerable distances from the promoter; promoter-proximal elements are close to the promoter

D.   Are DNA sequences; promoter-proximal elements are proteins

29: The redundancy of the genetic code is a consequence of ______.

A.   Having more codons than amino acids

B.   Having four different letters (As, Cs, Gs, and Us) in the genetic alphabet

C.   Having fewer codons than there are amino acids

D.   Having three-letter-long genetic words (codons

E.   Having an equal number of codons and amino acids

30: The structural framework of a blood clot is formed by __________.

A.   A fibrinogen polymer

B.   Soluble fibrin

C.   A fibrin polymer

D.   Soluble fibrinogen

E.   A thrombin polymer

31: The target organ of oxytocin is the smooth muscle of the _____.

A.   Liver

B.   Uterus

C.   Lungs

D.   Pancreas

32: The tract that carries sensations from muscle spindles to the cns is the __________.

A.   Posterior column

B.   Anterior spinothalamic

C.   Lateral spinothalamic

D.   Spinocerebellar

33: To recycle nutrients, an ecosystem must have, at a minimum, _____.

A.   Producers, primary consumers, secondary consumers, and decomposers

B.   Producers

C.   Producers, primary consumers, and decomposers

D.   Producers and decomposers

34: Copernicus proposed a heliocentric model for the solar system primarily because ________.

A.   It was much simpler than the Ptolemaic model

B.   It is attractive and increases if their masses increase.

C.   The center of mass and nothing

D.   The shape of a planet's orbit is an ellipse

35: Ddt, dde, pcbs, and pbdes are all ________.

A.   Non-biodegradable and subject to bioaccumulation and/or biomagnification

B.   A biodegradable and do not persist

C.   Top consumers susceptible to eggshell damage caused by DDT

D.   None of this

36: Industrial ecologists ________.

A.   Urge an emphasis on internal manufacturing costs rather than external costs

B.   Favor an economy that moves linearly rather than circularly

C.   Primarily analyze industrial inputs

D.   Advocate for taxes on green industries

E.   Redesign industrial systems to maximize physical and economic efficiency

37: The evolution of eukaryotic cells most likely involved _____.

A.   Endosymbiosis of an aerobic bacterium in a larger host cell—the endosymbiont evolved into mitochondria

B.   No ribosomes are attached to its surface.

C.   Function of the Golgi apparatus in sorting and directing membrane components

D.   Are formed from products synthesized by the endoplasmic reticulum and processed by the Golgi

38: Uniform spacing patterns in plants such as the creosote bush are most often associated with _____.

A.   Chance

B.   Patterns of high humidity

C.   The random distribution of seeds

D.   Competitive interaction between individuals of the same population

E.   The concentration of nutrients within the population's range

39: Unikonta is a supergroup that includes all of the following except _____.

A.   Fungi

B.   Protists

C.   Animals

D.   Plants

40: What was an early selective advantage of a coelom in animals? a coelom _____.

A.   Contributed to a hydrostatic skeleton, allowing greater range of motion

B.   Was a more efficient digestive system

C.   Allowed cephalization and the formation of a cerebral ganglion

D.   Allowed asexual and sexual reproduction

41: The most important feature that permits a gene to act as a molecular clock is _____.

A.   Being acted upon by natural selection

B.   A recent origin by a gene-duplication event

C.   A reliable average rate of mutation

D.   A large number of base pairs

42: The most active form of ____________ is called calcitriol.

A.   Calcitonin

B.   Osteoblastic activity

C.   Vitamin D

D.   Vitamin A

43: (intro) the amount of life on the ocean floor depends primarily on _________.

A.   Sediment thickness

B.   Oxygen supply

C.   The amount of light

D.   Temperature

E.   The productivity of the surface layer above it

44: In the myogenic response, ________.

A.   Muscle contraction promotes venous return to the heart

B.   Ventricular contraction strength is decreased

C.   Vascular smooth muscle responds to stretch

D.   Endothelins dilate muscular arteries

45: Opportunistic species typically ______.

A.   Have a large number of offspring

B.   A density-independent factor

C.   Few offspring and good parental care

D.   Most individuals survive to older age intervals

46: The body fluids of an osmoconformer would be ________ with its ________ environment

A.   Hyperosmotic; freshwater

B.   Isotonic; freshwater

C.   Hyperosmotic; saltwater

D.   Isoosmotic; saltwater

E.   Hypoosmotic; saltwater

47: During weeks 17-20, quickening occurs, which is when the __________.

A.   Fetus' sense of hearing is developing at a rapid pace

B.   Mother can hear the fetus' heartbeat with headphones

C.   Fetus' heart rate increases to 150 beats per minute

D.   Mother is able to feel the fetus move inside her womb

48: Cutting the left optic nerve in front of the optic chiasm would result in blindness in the ____.

A.   Ight eye

B.   Left eye

C.   Peripheral vision of botheyes

D.   None of these

49: Secondary hypertension ____________________. select all that apply.

A.   Has no negative effect on the heart.

B.   Is due to the presence of another disease, such as Cushing's syndrome.

C.   Accounts for 5% to 10% percent of all hypertension cases.

D.   S a blood pressure ≤ 160/100 mm Hg.

E.   Is also known as essential hypertension.

50: Sensory information that arrives at the cns is routed according to the ________ of the stimulus.

A.   Location

B.   Temperature

C.   Nature

D.   Speed

E.   Both A and C