ASVAB Science Biology Practice Test 5

Question – 1

1. Organisms exhibiting high intrinsic growth rates have

  • A. Short generation time

  • B. Low carrying capacity

  • C. No courtship behaviors

  • D. Long generation time

  • E. High carrying capacity

  • Answer:A

  • Answer Explanation:Intrinsic growth rate is the maximum rate at which a particular population would grow under the absence of external growth suppressing agents or conditions. Organisms possessing high intrinsic growth rates have short generation time (time needed to produce the offspring).

Question – 2

2. What are the terms used to indicate the excessive and very less amount of amniotic fluid respectively?

  • A. Hydramnios and oligohydramnios

  • B. Oligohydramnios and hydramnios

  • C. Hyperamniosis and hypoamniosis

  • D. Oligohydramnios and polyhydramnios

  • E. Amniocentesis and polyamnios

  • Answer:A

  • Answer Explanation:Amniotic sac contains amniotic fluid for the protection of developing embryo. Its normal amount found to be ranges from 500mL to 1000mL. An excess in its amount (say more than 2000mL) leads to a condition called hydramnios (polyamnios or polyhydramnios). Presence of very little amount of amniotic fluid (say less than 500 mL)results in oligohydramnios.

Question – 3

3. The cells that are developed into placenta are

  • A. Embryoblast

  • B. Epiblast

  • C. Hypoblast

  • D. Trophoblast

  • E. Ectoblast

  • Answer:D

  • Answer Explanation:Trophoblast is the outer most layer of blastocyst and it forms the placenta which attaches to the uterine wall and takes nourishment from the mother. Embryoblastis the inner cell mass of blastocyst from which the three germ layers arise. Embryoblast contains the outer epiblast (ectoblast) and the inner hypoblast (endoblast).

Question – 4

4. In which of the following stages is a baby’s sex decided?

  • A. Zygote

  • B. Embryo

  • C. Gastrula

  • D. Blastula

  • E. Neurula

  • Answer:A

  • Answer Explanation:In human, after fertilization of the male and female gametes the zygote formed contains either XX chromosomes (which develop into female) or XY chromosomes (which develop into male). This is decided by the sperm (X or Y) that fuses with the ovum.

Question – 5

5. The genetic phenomenon in which the multiple alleles coexist at a locus is called

  • A. Pleomorphism

  • B. Polymorphism

  • C. Epitasis

  • D. Codominance

  • E. Genetic diversity

  • Answer:B

  • Answer Explanation:The existence of multiple genetic variants (alleles) at a locus is called genetic polymorphism. Pleomorphism is the occurrence of many structural forms of an organism during its life cycle. Epistasis refers to the suppression or masking of the phenotypic expression of one gene by another gene. Codominance is the complete expression of both the alleles of a heterozygous pair. Genetic diversity refers to the genetic variations that occur within species.

Question – 6

6. A transcriptome can be defined as

  • A. The complete set of DNA molecules

  • B. The complete set of genes

  • C. The complete set of non- coding RNAs

  • D. The complete set of translated proteins

  • E. The complete set of RNA molecules

  • Answer:E

  • Answer Explanation:A transcriptome refers to the complete set of transcripts under particular conditions. It is defined as the set of RNA molecules present in a cell or cell type or an organism. The transcriptome includes all the RNA molecules regardless of the translation i.e. it includes mRNAs and non- coding RNAs. The complete sets of genes and proteins are called genome and proteome respectively.

Question – 7

7. Presence of both male and female characteristics in an animal is referred as

  • A. Polymorphic

  • B. Bilaterally symmetric

  • C. Gynandromorphic

  • D. Dioecious

  • E. Heteromorphic

  • Answer:C

  • Answer Explanation:Animals (mainly insects) that show male characters on certain regions and female characters on other regions of the body are called as gynandromorphs. Polymorphic means having more than one form. Bilateral symmetry refers to the divisible property of an animal’s body part into two equal halves by only one plane. Dioecious refers to the presence of male and female structures on separate plants of the same species. Showing different forms in different stages of life is called heteromorphic.

Question – 8

8. Blood typing in humans is an example for

  • A. Codominance

  • B. Multiple alleles

  • C. Polyphenism

  • D. Both a and b

  • E. Both b and c

  • Answer:D

  • Answer Explanation:In human beings, the ABO blood typing exists. Since there are three alleles that govern the single character of blood type, the blood typing in humans is said to be multiple alleles. The alleles of A and B blood types can be expressed together and so they are co-dominant. Single genotype producing different phenotypes due to environmental influence is called polyphenism.

Question – 9

9. The reproductive strategy in which an organism reproduces single time in its life span is called

  • A. Viviparity

  • B. Oviparity

  • C. Ovoviviparity

  • D. Semelparity

  • E. Iteroparity

  • Answer:D

  • Answer Explanation:An organism is said to be semelparous if it is capable of reproducing only once in its lifetime. Iteroparous organism is the organism that reproduces repeatedly in its lifetime. Viviparity, oviparity and ovoviviparity are the terms related to the internal or the external development of embryos.

Question – 10

10. A shared character of two or more taxonomic groups that is derived or specialized from their last common ancestor is called

  • A. Synapomorphy

  • B. Symplesiomorphy

  • C. Plesiomorphy

  • D. Pleomorphy existence of an organism in more than one form in the life cycle.

  • E. Heteromorphy differ in form from the standard form

  • Answer:A

  • Answer Explanation:Apomorphy refers to a derived or a specialized character. Synapomorphy is a type of apomorphy which is shared by more than one taxon and is inherited from the taxon’s immediate common ancestor. Plesiomorphy is an ancestral or a primitive character. Symplesiomorphy refers to the shared character of many groups that is inherited from ancestors older than the immediate ancestor. Pleomorphy is the existence of an organism in more than one form in its life cycle. Heteromorphy is the variation in the form from the standard form.

Question – 11

11. A plant that lives in calcium- rich soil is called

  • A. Calcifuge

  • B. Calciplant

  • C. Limnophyte

  • D. Agarophyte

  • E. Calcicole

  • Answer:E

  • Answer Explanation:Calcicole is a plant that grows well in calcareous soil (lime- rich soil). Calciphile and calciphyte are the other terms by which such a plant is referred. Some plants cannot tolerate more calcium so they are not capable of living in lime- rich soil. Such plants are called calcifuges. Limnophytes are the plants that grow in marshy conditions and in shallow water. Agarophyte is a sea weed from which agar is produced.

Question – 12

12. _______ is the term used to represent the reappearance of ancestral characters in descendants.

  • A. Cladogenesis

  • B. Anagenesis

  • C. Parallelism

  • D. Atavism

  • E. Convergent evolution

  • Answer:D

  • Answer Explanation:Atavism is the reappearance of any ancestral character that is absent in the intervening generations. Anagenesis is the gradual evolution of a species into a different species. Cladogenesis is the branching evolution which splits the lineage into two or more. Parallel evolution is the similar evolutionary change in different organisms that arises due to similar environmental influence. Parallel evolution that leads to very similar morphology is called convergent evolution.

Question – 13

13. The volume of air inspired or expired during one respiratory cycle is known as

  • A. Inspiratory reserve volume

  • B. Expiratory reserve volume

  • C. Tidal volume

  • D. Residual volume

  • E. None of the above

  • Answer:C

  • Answer Explanation:Tidal volume represents the lung volume. Tidal volume is the total volume of air inspired or expired during one respiratory cycle. Inspiratory reserve volume is the additional volume of air a person can inspire by a forcible inspiration. Expiratory reserve volume refers to the additional volume of air a person can expire forcibly. Residual volume is the volume of air present in lungs even after forcible exhalation.

Question – 14

14. Jumping genes are also known as

  • A. Heterochromatin

  • B. Euchromatin

  • C. Transposons

  • D. Overlapping genes

  • E. Episomes

  • Answer:C

  • Answer Explanation:Transposons or jumping genes are DNA sequences that can jump from one site of the genome to another site. Transposition causes inactivation of genes. Transposons were discovered by Barbara McClintock.

Question – 15

15. Thick and multi-layered peptidoglycan is a characteristic of

  • A. Bacteriophages

  • B. Gram positive bacteria

  • C. Gram negative bacteria

  • D. Both b and c

  • E. None of the above

  • Answer:B

  • Answer Explanation:Bacterial cell wall is made up of peptidoglycan which is thick and multi- layered in gram positive bacteria and thin and single- layered in gram negative bacteria. Bacteriophages are the viruses that infect bacteria.

Score: 0/10

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