June 2013 CSIR NET JRF Biology Exam - Practice Questions

1. Vascular tissue that transports water in leaves connects directly to

• meristems in the root tip
• pistils in the flower
• root hairs in the epidermis
• xylem in the stem

2. Which three processes are indicated by the arrows in the diagram below?

• ingestion, diffusion, excretion
• ingestion, digestion, egestion
• cyclosis, meiosis, mitosis
• diffusion, active transport, cyclosis

3. A biologist analyzed the liquid in the nephridia of earthworms and the liquid in the nephrons of humans. The liquid found in both organisms was most likely composed of water containing

• sugar and uric acid
• sugar and ammonia
• salts and urea
• salts and amino acids

4. Which letter in the diagram below indicates the structure that is most closely associated with excretion?

• A
  B
  C
  D

5. Which process is correctly paired with the waste it produces?

• respiration: methane
• protein metabolism: ammonia
• dehydration synthesis: carbon dioxide
• hydrolysis: urea

6. In grasshoppers and humans, locomotion is accomplished by means of

• the interaction of muscles and jointed appendages
• jointed chitinous appendages
• a carilaginous endoskeleton
• the interaction of muscles and an exoskeleton

7. During aerobic respiration, the chemical energy of glucose is gradually released, producing 36 ATP and

• NH3 and O2
• NH3 and CO2
• H2O and O2
• H2O and CO2

8. In trees, shrubs and other woody plants, the exchange of CO2 and O2 with the environment may occur through structures known as

• spiracles
• anthers
• lenticels
• rhizoids

9. Small hairs on the legs of certain insects have the ability to detect chemicals. These hairs function as

• receptors
• effectors
• stimuli
• responses

10. Which organism has a primitive brain, a ventral nerve cord and antennae?

• bryophyte
• grasshopper
• chordate
• jellyfish

Answer
1. xylem in the stem
2. ingestion, diffusion, excretion
3. salts and urea
4. D
5. protein metabolism: ammonia
6. the interaction of muscles and jointed appendages
7. H2O and CO2
8. lenticels
9. receptors
10. grasshopper

June 2013 CSIR NET Biology Exam - Practice Questions

1. After several days near a window, a house plant began to grow toward the window. This growth pattern occurred because auxins

• prevent the growth of cells on the light side of the plant
• stimulate cell growth on the dark side of the plant
• are activated when they are exposed to light
• are distributed unevenly throughout the plant stem

2. Which type of digestion occurs in the mouth when an individual chews a piece of bread?

• mechanical digestion only
• chemical digestion only
• both mechanical and chemical digestion
• neither mechanical nor chemical digestion

3. Which structure is lined with a ciliated mucous membrane that warms, moistens and filters air?

• pharynx
• alveolus
• epiglottis
• nasal cavity

4. Which transport structures have specialized regions for filtering out bacteria and dead cells?

• arteries
• capillaries
• veins
• lymph nodes

5. In humans the ureter transports unine from the

• blood to kidney
• liver to kidney
• kidney to urinary bladder
• urinary bladder to outside of the body

6. If a motor neuron involved in a reflex arc is damaged, which is least likely to occur?

• contraction of muscle
• stimulation of an interneuron
• reception of a stronger stimulus by the sense organ
• secretion of a neurotransmitter by the sensory neuron

7. Which system is most closely associated with the production of regulatory chemicals by glands?

• nervous
• circulatory
• endocrine
• exocrine

8. The inelastic connective tissue that attaches a muscle in the lower leg to the heel is known as

• a tendon
• a ligament
• cartilage
• endodermis

9. Which process results in offspring with a genetic makeup identical to that of the parent?

• fusion of gametes
• vegetative propagation
• internal fertilization
• meiotic cell division

10. The uncontrolled division of certain extremely healthy body cells, which invade the surrounding tissues and interfere with the normal functioning of the body, is known as

• cancer
• a viral infection
• oogenesis
• regeneration

Answer
1. stimulate cell growth on the dark side of the plant
2. both mechanical and chemical digestion
3. nasal cavity
4. lymph nodes
5. kidney to urinary bladder
6. contraction of muscle
7. endocrine
8. a tendon
9. vegetative propagation
10. cancer

CSIR NET Life science 2013 Exam - Practice Questions

1. Corals reproduce by forming multicellular outgrowths from the body wall that detach and develop into independent organisms. Which statement most closely describes this form of reproduction in another organism?

• Molds reproduce by sporulation.
• Hydras reproduce by budding.
• Paramecia reproduce by binary fission.
• Maple trees reproduce by seed formation.

2. Which reproductive process is correctly paired with the structure in which it occurs?

• meiosis: oviduct
• fertilization: gonad
• gametogenesis: testis
• pollination: antheridium

3. A McIntosh apple tree brand was grafted to an Ida Red apple tree. The fruit produced by the newly grafted piece will be

• Ida Red apples only
• McIntosh apples only
• 50 % McIntosh and 50% Ida Red
• apples that are a composite of both McIntosh and Ida Red varieties

4. Why is the release of 2000 to 10000 eggs by a female salmon during one season considered a favorable reproductive adaptation?

• External fertilization increases the chance of sperm reaching the eggs.
• Overproduction increases the rate of embryo development.
• The species is declining, so the reproductive rate has increased to respond to that.
• Unfavorable environmental conditions may destroy gametes.

5. Animals that produce embryos that are born small and relatively immature and must complete their development in a pouch are known as

• marsupials
• monotremes
• placental mammals
• nonplacental mammals

6. The brightly colored, highly scented flowers on a rosebush are an adaptation for

• wind pollenation
• insect pollination
• spore production
• embryo nutrition

7. Using the results of his experiments with pea plant crosses, Mendel discovered

• the principles of dominance, segregation and inedpendent assortment
• that pea plants develop mutations after exposure to radiation
• intermediate inheritence and gene linkage
• that DNA is involved in the inheritence of dominant traits

8. In a certain variety of chicken, the genes for black feather color and the genes for white feather color are codominant. This variety of chicken will most likely have

• three possible phenotypes for feather color
• white feather color
• black feather color
• only two genotypes for feather color

9. In fruit flies red eye color (R) is dominant and white eye color (r) is recessive. The allele for eye color is carried on the X chromosome. Which cross would most likely produce 50% white-eyed males and 50% red-eyed males?

• X^RX^R x X^RY
• X^RX^R x X^rY
• X^RX^r x X^rY
• X^rX^r x X^RY

10. A mutation may be passed on to future generations if it occurs within specialized cells of the

• ovary
• brain
• heart
• liver#

Answer
1. Hydras reproduce by budding.
2. gametogenesis: testis
3. McIntosh apples only
4. Unfavorable environmental conditions may destroy gametes.
5. marsupials
6. insect pollination
7. the principles of dominance, segregation and inedpendent assortment
8. three possible phenotypes for feather color
9. XRXR x XRY
10. ovary

CSIR NET Life science June 2013 - Practice Questions

1. An example of a mutagenic agent is

• an amine
• acetylcholine
• ultraviolet light
• sulfer dioxide

2. Kernal color is a traite etermined by two alleles. The dominant allele (P) produces a purple color and the recessive allele (p) produces a yellow color. Purple kernels and yellow kernals can best be described respectively as

• heterozygous dominant and homozygous recessive
• homozygous recess and heterozygous dominant or homozygous dominant
• homozygous recessive or heterozygous dominant
• heterozygous dominant or homozygous dominant and homozygous recessive

3. The genetic process by which alleles are transferred to complementary chromatids at the same or very similar times producing genetic variability within the organism for the possibility of future genetic variability within that organism’s population is called what?

• chromosomal mutation
• nondisjunction
• independent assortment
• crossing-over

4. A DNA nucleotide may contain

• deoxyribose, cytosine, lipid
• deoxyribose, thymine, phosphate
• ribose, uracil, polypeptide
• ribose, adenine, phosphate

5. Fossils of an extinct species of giant armadillo were found to be similar to a smaller species of armadillo presently inhabiting the same region. This similarity could best be explained on the basis of

• evolution from older forms
• inheritence of acquired characteristics
• use and disuse
• the heterotroph hypothesis

6. A study of the position and shape of the bones in the forelimbs of a flying squirrel, a bat and a beaver showed that the beaver and the flying squirrel appear to be most closely related. This determination was most likely based on a study in the field of comparative

• cytogenetics
• embryology
• biochemistry
• physical anatomy

7. By simulating conditions thought to have existed on a primitive Earth, Stanley Miller found that these conditions could result in the formation of

• today’s genetic molecules
• viral-like proteins
• organic compounds
• autotrophic molecules

8. According to the diagram pictured below, humans most closely relate to

• the ancestral primate
• chimpanzees
• gorillas
• orangutans

9. August Weismann conducted a series of experiments involving the removal of the tails of from several generations of mice. Which concept of LaMarckian evolution did he help disprove?

• natural selection
• gradualism
• inheritence of acquired traits
• geographic isolation

10. Modern evolutionary theory consists of the concepts of Darwin modified by knowledge concerning

• population statistics
• Mendel’s laws
• the idea of the survival of the fittest
• competition

Answer
1. ultraviolet light
2. heterozygous dominant or homozygous dominant and homozygous recessive
3. crossing-over
4. deoxyribose, thymine, phosphate
5. evolution from older forms
6. physical anatomy
7. organic compounds
8. chimpanzees
9. inheritence of acquired traits
10. Mendel’s laws

June 2013 CSIR NET Life science Exam - Model Questions

1. According to the heterotroph hypothesis, which gas was added to the environment by the first heterotrophs?

• nitrogen
• oxygen
• carbon dioxide
• water vapor

2. Which human activity would most likely result in the addition of an organism to the endangered species list?

• cover cropping
• use of pollution controls
• use of erosion controls
• irrigation

3. A typical aquarium ecosystem consists of

• plants and gravel
• fish, water and snails
• fish, plants, and snails
• water and gravel

4. The first organism in most natural food chains is

• an herbivore
• a decomposer
• photosynthetic
• carnivorous

5. Which factor is not necessary for an ecosystem to be self-sustaining?

• a constant source of energy
• living systems that incorporate energy into organic molecules
• a cycling ofmaterial between organisms and their environment
• an equal number of producers and consumers

6. Which title is most appropriate for the diagram below?

• Energy Flow and Material Cycles in an Ecosystem
• Evolution in an Ecosystem
• Succession in an Ecosystem
• The Water Cycle in an Ecosystem

7. Which substances are represented by A and B in the diagram below?

• A represents oxygen and B represents carbon dioxide
• A represents carbohydrates and B represents carbon dioxide
• A represents nitrogen and B represents carbon dioxide
• A represents carbon dioxide and B represents oxygen

8. Which group in the chart below contains only abiotic factors?

Group A	Group B	Group C	Group D
Sunlight Green plants Rainfall Consumers Oxygen	Sunlight Climate Rainfall Minerals Gases	Sunlight Green plants Rainfall Producers Carbon dioxide	Sunlight Rainfall Consumers Producers Water

• A
• B
• C
• D

Answer
1. carbon dioxide
2. irrigation
3. fish, plants, and snails
4. photosynthetic
5. an equal number of producers and consumers
6. Energy Flow and Material Cycles in an Ecosystem
7. A represents oxygen and B represents carbon dioxide
8. B

June 2013 CSIR NET Life science Exam - Practice Questions

1. Which activity is necessary for the survival of a species of amoeba but not necessary for the survival of an individual member of that species?

1. elimination of water by a contractile vacuole
2. cross-membrane movement of oxygen
3. ingestion
4. binary fission

2. Which term is defined as all the chemical reactions that are required to sustain life?

1. metabolism
2. regulation
3. nutrition
4. synthesis

3. A housecat is more closely related to a

1. dolphin
2. songbird
3. lynx
4. wolf

4. A structure that performs a specialized function within a cell is known as

1. a tissue
2. an organelle
3. an organ
4. a system

5. Which organism is considered an exception to the cell theory because it has a noncellular structure?

1. alga
2. bacterium
3. virus
4. moss

6. Which chemical compound makes up the greatest percentage of a protozoan?

1. nucleic acid
2. glucose
3. fatty acid
4. water

7. Which factor does not alter the rate of hydrolysis of maltose?

1. environmental temperature
2. environmental pH
3. substrate size and quantity
4. enzyme quantity

8. One immediate cause of a decrease in the rate of photosynthesis is a reduction in the availability of

1. carbon dioxide
2. carbon monoxide
3. hydrogen
4. nitrogen

9. The function of the gastric caecum in a grasshopper is most similar to the function of the

1. nephridium in an earthworm
2. pancreas in a human
3. anal pore in a paramecium
4. nerve net in a hydra

10. Which structure is most directly responsible for maintining homeostasis in all cells?

1. chloroplast
2. cell membrane
3. centriole
4. cell wall

Answer
1. binary fission
2. metabolism
3. lynx
4. an organelle
5. virus
6. water
7. substrate size and quantity
8. carbon dioxide
9. pancreas in a human
10. cell membrane