Biology: Topic-wise Test- 9 - NEET MCQ

• STD can be transmitted via sexual contact or contact of body fluids like blood.
• Sharing needles or blades can lead to the sharing of blood, and thus the infectious agent if anyone using it is infected.
• Hence, shaving blades must not be shared with friends and should be thrown away after each use.

Hence, the correct option is D.

NCERT Reference: topic “SEXUALLY TRANSMITTED DISEASES (STDs)” of chapter Reproductive Health.

The electron transport chain along with oxidative phosphorylation involves the synthesis of energy-rich ATP molecules with the help of energy released during the oxidation of reduced coenzymes (NADH₂ and FADH₂) formed during glycolysis and the Krebs cycle. A total of 10 NADH₂ and 2 FADH₂ molecules are produced during aerobic respiration. They help in the formation of 32 ATP molecules.

• When egg and sperm fuse, pregnancy occurs. The normal period of pregnancy is 40 weeks which is divided into 3 trimesters.
• The 3 trimesters are:
  (i) First Trimester: First 3 months
  (ii) Second Trimester: 4th to 6th months
  (iii) Third Trimester: 6th to 9th months
• MTP is considered safe up to the first trimester so, 6, 8, 12 weeks would be okay, but 18 weeks comes under the second trimester and MTP at this stage would be a huge risk for mother.

Thus, the MTP Act allows for the termination of pregnancy up to 12 weeks of pregnancy.

Hence, the correct option is C.
NCERT Reference: Topic “MEDICAL TERMINATION OF PREGNANCY (MTP)” of chapter Reproductive Health of NCERT.

• Zygote is diploid (46 chromosomes i.e. 23 pairs of chromosomes) and formed by fusion of male and female gametes.
• Spermatogonia are the cells on the inside wall of seminiferous tubules and consist of 46 chromosomes.
• The secondary oocyte is a haploid cell that develops from the primary oocyte during puberty. It is a haploid cell with 23 chromosomes.
• Oogonia are also diploid and are formed in the foetal ovary.​

Hence, the Correct Answer is C

NCERT Reference: Topic Gametogenesis”of chapter - Human Reproduction of NCERT

In vitro fertilization technique involves fertilization outside the body in culture media followed by embryo transfer in the fallopian tube or uterus.

Hence, the correct option is A.

NCERT Reference: Topic “INFERTILITY” of chapter Reproductive Health of NCERT.

Nereis belongs to phylum Annelida and scorpion, cockroach and silver fish belong to phylum Arthopoda. They all possess dorsal heart.

The overall goal of glycolysis, Krebs cycle and electron transport system is the formation of ATP step-wise. The three processes are involved in cellular respiration of food to produce energy, which will be used for various cellular activities. 

• Animals that belong to the phylum Platyhelminthes to Chordata are all triploblastic.
• But Platyhelminthes and aschelminthes belong to pseudocoelomates.
• Annelids, arthropods, echinoderms and chordates are under eucoelomates. This means not all triploblastic animals are eucoelomates. 
• Pseudocoelomates have false coelom while eucoelomate animals only have the true coelom. 

Hence, both statement 1 and statement 2 are incorrect. 

Tricarboxylic acid cycle or the citric acid cycle or the Krebs cycle takes place within the mitochondrial matrix of the cell. The end product of Krebs cycle is 2 GTP, 6 NADH and 4 carbon dioxide.

1. Krebs cycle is also known as the citric acid cycle because this reaction starts with the six-carbon compound which is citric acid. It occurs in the mitochondrial matrix.
2. Krebs cycle is a closed-loop cycle. And each loop of the cycle generates a molecule of ATP. This cycle consists of eight steps which include redox, dehydration, hydration, and decarboxylation reactions. It is an aerobic pathway because NADH is produced and the electrons released are used up in the next cycle which uses oxygen.
3. The process of the cycle starts with the condensation of acetyl- CoA with oxaloacetate.
4. This reaction is controlled by the amount of ATP present.
5. If the ATP level increases then the rate of the reaction decreases and vice versa. After glycolysis, the pyruvate is then converted into acetyl CoA which enters the citric acid cycle.
6. The Krebs cycle is the pathway that all organisms use to generate energy. The intermediate compound that links pyruvate to the Krebs cycle is Acetyl CoA.
7. So, the answer is option (B) ‘the intermediate compound which links glycolysis with the Krebs cycle is malic acid’.

Amphetamines is kind of drug which is used as stimulant. It is a strong CNS stimulant that is used in the treatment of ADHD. Lysergic acid dimethyl amide is not a narcotic and heroin is not a psychotropic agent.

Menstrual Cycle Phases:

• The menstrual cycle is divided into several phases, including the follicular phase, ovulation, and the luteal phase.

(i) Follicular Phase:

• During the follicular phase, the level of estrogen increases, which stimulates the growth and development of follicles containing the eggs (ova).
• Estrogen also helps in thickening the endometrium (uterine lining) to prepare it for the potential implantation of a fertilized egg.

(ii) Ovulation:

• Ovulation is triggered by a surge in luteinizing hormone (LH), not by high levels of estrogen, so statement a is incorrect.
• During ovulation, a mature egg is released from the dominant follicle and enters the fallopian tube.

(iii) Luteal phase (post ovulatory phase):

• After ovulation, the remnants of the dominant follicle transform into the corpus luteum, which secretes progesterone.
• Progesterone is responsible for maintaining the endometrial lining and preparing it for the possible implantation of a fertilized egg.

Hence, statement b is correct, as progesterone levels are high during the post ovulatory phase of the menstrual cycle.

Sperms and oogonial cells:

• Statement c is incorrect because sperms released from seminiferous tubules are not fully motile, but they gain motility as they travel through the epididymis, where they mature and become capable of fertilizing an egg.
• Statement d is also incorrect because oogonial cells do not proliferate and give rise to functional ova during regular cycles. Instead, oogonial cells differentiate into primary oocytes before birth, and these primary oocytes are arrested in meiosis until puberty. From puberty onwards, a few primary oocytes resume meiosis and develop into functional ova during each menstrual cycle.

So, the correct answer is "Progesterone level is high during the post-ovulatory phase of the menstrual cycle."

Hence, the Correct Answer is B

NCERT Reference: Topic “Menstrual Cycle”of chapter : Human Reproduction of NCERT.

• 10th to 17th day of menstrual cycle is called the risky period of conception as during which ovulation takes place.
• If sexual intercourse occurs during this period, there is a very high chance of fertilisation that may leads to pregnancy.

Hence, the correct option is D.
NCERT Reference: topic “POPULATION EXPLOSION AND BIRTH CONTROL” of chapter Reproductive Health of NCERT.

(i) Diploblastic animals have two germinal layers (ectoderm and endoderm) during embryonic development
Example: Poriferans.
(ii) Triploblastic animals have three germinal layers (ectoderm, mesoderm and endoderm) during embryonic development
Example: Platyhelminthes.

• Good birth control measures should be easily available and cheaper.
• There should not be any interference with sexual desire without any side effect.

Hence, the correct option is C.
NCERT Reference: Topic “POPULATION EXPLOSION AND BIRTH CONTROL” of chapter Reproductive Health of NCERT.

Figure 'A' is of Hydra which has radial symmetry and figure 'B' is of Cancer (crab) which has bilateral symmetry.

Opioids are the drugs which bind to specific opioid receptors present in our central nervous system and gastrointestinal tract.

(A) Cellular level
(B) Radial symmetry
(C) Bilateral symmetry
(D) Pseudocoelomates
(E) Coelomates

AIDS day is celebrated on December 1 all over the world. Its aim is to create awareness about this dreaded disease.

• Within the framework of the World Health Organization's (WHO) definition of health as "a state of complete physical, mental and social well-being, and not merely the absence of disease or infirmity", reproductive health, or sexual health/hygiene, addresses the reproductive processes, functions, and system at all stages of life.
• The different aspects of the reproductive phase include knowledge and precaution against STDs, different available contraceptive methods as well as assisted reproductive technologies for infertile couples.

Hence, the correct option is A.
NCERT Reference: topic “REPRODUCTIVE HEALTH – Birth Control” of chapter: Reproductive Health.
 

(i) Diploblastic - Poriferans, Coelenterates

(ii) Triploblastic - Platyhelminthes to Chordates

(iii) Acoelomate - Poriferans, Coelenterates, Platyhelminthes

(iv) Pseudocoelomate - Aschelminthes/Roundworms

(v) Eucoelomate - Annelids to Chordates

So, the correct answer is '(i), (ii), (iii), (iv) and (v)'.

AIDS is caused by Human immunodeficiency virus of member of group of virus called retrovirus. It is a type of RNA virus that inserts a copy of its genome into the DNA of a host cell that it invades, thus changing the genome of that cell.

Skin and respiratory allergy problems arise in hilly areas due to allergen present in these areas. Allergen induce inflammatory reaction in the body.

Plasmodium completes their life cycle in two hosts, female anopheles and human beings. The motile zygote of plasmodium occurs in gut of female anopheles, which get transferred to human being during mosquito bite.

Saheli is an oral contraceptive for females containing non-steroidal preparation. It is different from the other pills as it should be taken once in a week irrespective of daily in case of other pills.

Hence, the correct option is B.
NCERT Reference: Topic “POPULATION EXPLOSION AND BIRTH CONTROL” of chapter Reproductive Health of NCERT.

The release of toxic haemozoin by the ruptured RBCs during malarial infection accounts for the recurrence of high fever and chill every 3-4 days.

Figure 'A' is of coelomates (Annelids), Figure 'B' is a pseudo-coelomates (Aschelminthes) and Figure 'C' is a acoelomates (Plathyhelminthes).

AIDS can be transmitted from infected person to healthy person through blood transfusion. The most common way of transmission of AIDS is during sexual intercourse with multiple partners without protection.

Cancer cells divide rapidly and hence they are said to be more active with a less prominent nucleus and low-density cytoplasm.

Hence, they get destroyed easily by laser treatment. Moreover, the form lumb in a certain place which can be easily distinguished by the doctors.

• The inability to conceive even after two years of unprotected sexual co-habitation is called infertility. This may be due to not functioning of the male or female reproductive system properly.
• The couples can be assisted to have children through certain special techniques called the assisted reproductive technologies (ART).

The applications of reproductive technology are:
(i) Test tube baby
(ii) Artificial insemination technique (AIT)
(iii) Gamete intra Fallopian transfer (GIFT)
(iv) lntra cytoplasmic sperm injection (ICSI)

Hence, the correct option is B.
NCERT Reference: topic “INFERTILITY” of chapter Reproductive Health of NCERT.