The testes are situated outside the abdominal cavity within a pouch called the scrotum. This is necessary as:
1. | The scrotum can contain lengthy ducts for the transfer of sperms |
2. | Scrotum helps in maintaining the low temperature of the testes necessary for spermatogenesis |
3. | Scrotum reduces the pressure around the testes necessary for spermatogenesis |
4. | Scrotum can store huge amounts of sperms |
Corpus luteum is essential for:
1. Release of ovum
2. Development of follicles
3. Maintenance of endometrium
4. Contraction of the myometrium
Identify the incorrectly matched pair:
1. |
Triploid nutritive tissue of a seed deposited externally to the embryo sac |
Perisperm |
2. |
The tissue that arises from the ripened ovary wall of a fruit; the fruit wall |
Pericarp |
3. |
The natural or artificially induced production of fruit without fertilisation of ovules |
Parthenocarpy |
4. |
Asexual reproduction where the growth and development of embryos occur without fertilization by sperm |
Parthenogenesis |
Assertion: | Hybrid varieties of several of our food and vegetable crops are being extensively cultivated. |
Reason: | Hybrid seeds have to be produced every year. |
The spermatids are transformed into spermatozoa by a process called:
1. | Spermiation | 2. | Spermatocytogenesis |
3. | Spermiogenesis | 4. | Spermatolysis |
The phenomenon wherein, the ovary develops into a fruit without fertilisation is called:
1. | Parthenocarpy | 2. | Apomixis |
3. | Asexual reproduction | 4. | Sexual reproduction |
The signals of fetal ejection reflex originate from:
1. Maternal pituitary
2. Maternal hypothalamus
3. Fully developed fetus and placenta
4. Fetal pituitary
The trophoblast cells of the blastocyst form:
1. | Embryo | 2. | Umbilical cord |
3. | Placenta | 4. | Teratoma |
What is released at ovulation?
1. | Primary oocyte arrested at meiosis I |
2. | Primary oocyte arrested at meiosis II |
3. | Secondary oocyte arrested at meiosis I |
4. | Secondary oocyte arrested at meiosis II |
Which hormone is mainly secreted by the developing follicles during the proliferative phase of the menstrual cycle?
1. | LH | 2. | FSH |
3. | Progesterone | 4. | Estrogen |
Plants have developed many mechanisms to encourage cross-pollination that include:
I. | Asynchrony between pollen release and stigma receptivity |
II. | Placing of pollen and stigma at different positions |
III. | Self-incompatibility |
IV. | Dioecy |
What would be true regarding these mechanisms?
1. | I and II prevent autogamy and geitonogamy |
2. | III is a genetic mechanism that inhibits pollen germination or pollen tube growth |
3. | IV is a very common [found in the majority] mechanism seen in flowering plants |
4. | I, II, and III invariably lead to xenogamy |
Majority of plants:
1. | Use abiotic agents for pollination |
2. | Use biotic agents for pollination |
3. | Do not use any agent for pollination |
4. | Use both abiotic and biotic agents for pollination. |
At the birth of the female child, the follicles in her ovaries contain:
1. | Primary oocytes that have been arrested at the S phase of the cell cycle |
2. | Primary oocytes that have been arrested at prophase I of meiosis I |
3. | Secondary oocytes that have been arrested prophase I of meiosis I |
4. | Secondary oocytes that have been arrested at metaphase II of meiosis II |
The ‘family planning’ programs in India were initiated in:
1. 1947 | 2. 1951 | ||
3. 1957 | 4. 1961 |
Transfer of pollens from the anther to the stigma of the same flower is called:
1. | Autogamy | 2. | Geitonogamy |
3. | Xenogamy | 4. | Cleistogamy |
Barrier methods for contraception work on the principle of:
1. Preventing fertilization
2. Preventing implantation
3. Preventing ovulation
4. Preventing embryo development
A plant, on repeated self-pollination, preserves the trait expressed for many generations. Such a plant is said to be:
1. | Panmictic | 2. | Homologous |
3. | Apomictic | 4. | Pure line |
Mendel’s work remained unrecognised till 1900. Which of the following was not a reason for this?
1. | His work was widely publicised and it brought a bad name to Mendel. |
2. | His concept of factors as stable and discrete units that did not ‘blend’ was not accepted. |
3. | His approach of using mathematics to explain biological phenomena was unacceptable. |
4. | He could not provide any physical proof for the existence of factors or say what they were made of. |
The number of alleles, the genotypic combinations, and phenotypes in the ABO system are respectively:
1. | 3, 6 and 4 | 2. | 3, 4 and 6 |
3. | 2, 3 and 4 | 4. | 2, 3, and 6 |
What is the F2 genotypic ratio in cases of incomplete dominance?
1. | 1 : 1 | 2. | 3 : 1 |
3. | 1 : 2 : 1 | 4. | 1 : 1 |
A high success rate of preventing pregnancy by the insertion of IUD as an emergency contraceptive within 72 hours of coitus suggests that:
1. | There is a latency between the release of the ovum and it getting ready for fertilization |
2. | The journey from the point of insemination to the site of fertilization is very long for a very small-sized sperm and takes considerable time. |
3. | IUDs may also make the uterine endometrium hostile to implantation. |
4. | If the secretion of hCG by the trophoblast cells can be stopped, it will lead to spontaneous abortion as happens due to the insertion of IUDs. |
In the ‘test–tube baby’ procedure:
1. | Fertilization is in-vitro but embryo development is in-vivo |
2. | Fertilization is in-vivo but embryo development is in-vitro |
3. | Both fertilization and embryo development are in-vitro |
4. | Both fertilization and embryo development are in-vivo |
‘When two pairs of traits are combined in a hybrid, segregation of one pair of characters is independent of the other pair of characters’. This is the statement of:
1. Law of Dominance
2. Law of segregation
3. Law of Independent Assortment
4. Law of Linkage
A graphical representation to calculate the probability of all possible genotypes of offspring in a genetic cross is called as:
1. | Forked line diagram | 2. | Punnett square |
3. | Pedigree chart | 4. | Idiogram |
Consider the transcription unit given in the following diagram and choose the correct statements:
I: | The promoter on the template is situated upstream and 5’ to the structural gene. |
II: | It is the presence of the structural gene that defines the template strand. |
III: | The coding strand does not code for anything and is displaced during transcription. |
1. | I and II only | 2. | I and III only |
3. | II and III only | 4. | I, II and III |
The progeny of a dihybrid test cross AaBb x aabb show the following genotypes: AaBb 160, Aabb 460, aaBb 440, aabb 140. The recombination frequency between the two loci is:
1. | 12.5 % | 25 % | |
3. | 15 % | 4. | 30 % |
Which of the following codons has a dual role in the genetic code?
1. | AUG | 2. | GUG |
3. | CUG | 4. | UUG |
The lac Y gene codes for permease, which increases the permeability of the cell to:
1. | Glucose | 2. | Galactose |
3. | cAMP | 4. | β-galactosides |
1. | The former is a quantitative problem of synthesising too few globin molecules while the latter is a qualitative problem of synthesising an incorrectly functioning globin. |
2. | The former is a qualitative problem of synthesising too few globin molecules while the latter is a quantitative problem of synthesising an incorrectly functioning globin. |
3. | Both disorders are qualitative problems of synthesising too few globin molecules. |
4. | Both disorders are quantitative problems of synthesising too few globin molecules. |
In humans, the mechanism of sex determination is:
1. | XX – XY; male heterogamety |
2. | XX – XY; female heterogamety |
3. | XX – XO; male heterogamety |
4. | XX – XO; female heterogamety |
Statement I: | There is now enough evidence to suggest that essential life processes (such as metabolism, translation, splicing, etc.), evolved around RNA. |
Statement II: | DNA being double-stranded and having complementary strands further resists changes by evolving a process of repair. |
If each strand of a dsDNA acts as a template for a new strand, the two daughter DNAs will be:
1. | Complementary to each other |
2. | Identical to the parental DNA |
3. | Similar to each other |
4. | Complementary to the parental DNA |
The physiological basis of pleiotropy is:
1. | lack of independent assortment in linked genes |
2. | separation of homologous chromosomes at anaphase I in meiosis I |
3. | dominance is not an autonomous feature of an allele |
4. | inter-relationships of many metabolic pathways in the living organisms |
Consider the following statements:
I. | Deoxyribonucleoside triphosphates act as substrates as well as provide energy for polymerization reaction during DNA replication. |
II. | The replication of DNA is both semiconservative and semi-discontinuous |
III. | In bacterial DNA replication, there are multiple ori and replication fork moving bi-directionally |
Which of the above statements are true?
1. | I and II only | 2. | I and III only |
3. | II and III only | 4. | I, II, and III |
What facilitates the opening of the helix during the elongation step of transcription?
1. | RNA polymerase | 2. | Helicase |
3. | Topoisomerase | 4. | Gyrase |
Which of the following would be nucleoside found only in RNA?
1. | Thymidine | 2. | Cytidine |
3. | Uridine | 4. | Adenosine |
Identify the incorrect statement:
1. | In addition to recombination, the mutation is another phenomenon that leads to variation in DNA. |
2. | Chromosomal aberrations are commonly observed in cancer cells. |
3. | A classical example of a point mutation is sickle cell anemia. |
4. | Non-ionising radiations cannot be mutagens. |
A segment of DNA coding for a polypeptide is most accurately defined as:
1. | Operon | 2. | Gene |
3. | Recon | 4. | Cistron |
Which of the following is also called soluble RNA?
1. | tRNA | 2. | rRNA |
3. | mRNA | 4. | siRNA |
I: | The result at the end of 20 minutes excludes the ‘conservative’ mode of DNA replication. |
II: | The result at the end of 40 minutes excludes the ‘dispersive’ mode of DNA replication. |
1. | Autosomal recessive | 2. | Autosomal dominant |
3. | Sex-linked recessive | 4. | Sex-linked dominant |
Which one of the following would cause the Hardy-Weinberg principle to be inaccurate?
1. The size of the population is very large.
2. Individuals mate with one another at random.
3. Natural selection is present.
4. There is no source of new copies of alleles from outside the population.
The natural selection operating as shown in the given figure is called as:
1. | Disruptive | |
2. | Directional | |
3. | Stabilizing | |
4. | Retrogressive |
1. | Spallanzani | 2. | Francesco Redi |
3. | Louis Pasteur | 4. | van Helmont |
Southern blotting is transfer to nitrocellulose sheet from agar gel of:
1. | RNA | 2. | Proteins |
3. | DNA | 4. | Lipids |
1. | Only I is correct | 2. | Only II is correct |
3. | Both I and II are correct | 4. | Both I and II are incorrect |
1. | Homo habilis | 2. | Homo erectus |
3. | Homo ergaster | 4. | Homo neanderthelensis |
1. | Chlorophyte ancestors | 2. | Tracheophyte ancestors |
3. | Rhynia-type plants | 4. | Psilophytons |