Test: Zoology Mock Test - 1 - NEET MCQ

The Miller-Urey experiment simulated early Earth conditions and demonstrated that organic molecules, including amino acids, could be synthesized abiotically. This experiment is crucial for understanding the chemical origins of life.

The S phase (Synthesis phase) of the cell cycle is characterized by DNA replication and chromosome duplication. During this phase, each chromosome is replicated to produce two sister chromatids, effectively doubling the genetic material in preparation for cell division. This ensures that each daughter cell will receive an identical set of chromosomes.

Progesterone is a steroid hormone that is responsible for preparing the endometrium for uterine implantation of the fertilized egg.

Aldosterone is a mineralocorticoid which maintains the salt water balance in the body.

Testosterone, progesterone and androgen are corticosteroids.

Option A: Buthus (scorpion)

• Description: It has six pairs of appendages, book lungs for respiration, and the statement claims it is viviparous (gives birth to live young).
• Fact Check: Scorpions do have six pairs of appendages and use book lungs for respiration. However, while some scorpions give birth to live young, they do not have eggs that hatch within the female body as typical viviparous organisms do; instead, the young are born alive. This description mixes up terms but is essentially correct about scorpions being viviparous.

Option B: Pila (apple snail)

• Description: Body covered by a coiled calcareous shell, unsegmented with a distinct head, muscular foot, and visceral mass. The mouth contains a radula.
• Fact Check: This description is accurate for Pila, which is an apple snail with these characteristics.

Option C: Asterias (starfish)

• Description: Presence of water vascular system, development includes free-swimming larva, sexes are separate.
• Fact Check: Starfish do have a water vascular system which is a hydraulic system used for locomotion and feeding. They also have free-swimming larval stages and are generally gonochoric (having separate sexes), although some are hermaphroditic.

Option D: Octopus (devil fish)

• Description: Radula present, larva absent, ink glands present, shell is absent.
• Fact Check: Octopuses do have ink glands and lack an external shell. They do not have a radula (which is a feeding structure found in snails and other mollusks), and they do not produce larva; they hatch as miniature adults.

Foreskin is a double-layered fold of smooth muscle tissue, blood vessels, neurons, skin, and mucous membrane that covers and protects the glans penis and the urinary meatus when the penis is not erect.
The foreskin is mobile, fairly stretchable, and acts as a natural lubricant.

Bony fish and aquatic amphibians are ammonotelic because this method of excretion uses the least energy.

Surgical intervention blocks gamete transport and thereby prevent conception. Sterilisation procedure in the male is called ‘vasectomy’ and that in the female, ‘tubectomy’. In vasectomy, a small part of the vas deferens is removed or tied up through a small incision on the scrotum whereas in tubectomy, a small part of the fallopian tube is removed  or tied up through a small incision in the abdomen or through vagina. These techniques are highly effective but their reversibility is very poor

In a diploid, p and q represent the frequency of allele A and allele a. The frequency of AA individuals in a population is simply p2 . This is simply stated in another ways, i.e., the probability that an allele A with a frequency of p appear on both the chromosomes of a diploid individual is simply the product of the probabilities, i.e., p² . Similarly of aa is q² , of Aa 2pq. Hence, p ²+2pq+q²=1. This is a binomial expansion of (p+q)²

bioactive molecule, cyclosporin A, that is used as an immunosuppressive agent in organ-transplant patients, is produced by the fungus Trichoderma polysporum.
Primary treatment : These treatment steps basically involve physical removal of particles – large and small – from the sewage through filtration and sedimentation

• Ovarian follicles are the essential units of the female reproductive biology of mammals, each of which is packed with roughly spherical aggregations of cells found in the ovary.
• A Graafian follicle, or ovarian follicle, is present inside an ovary and is a minute cyst within which an egg, or ovum, develops.
• A Graafian follicle is a follicle that ruptures and releases its ovum when stimulated. Generally, women are born with many undeveloped follicles, each containing an immature ovum.
• As soon as puberty is attained and menstruation commences, one ovum matures each month inside its containing follicle.
• The follicle grows bigger and breaks at around day 14 of the cycle, discharging the ovum in a process known as ovulation.

Reproduction through fragmentation is observed in sponges, some cnidarians, turbellarians, echinoderms, and annelids.

In cockroach, a pair of much branched accessory or colleterial glands lies behind and above the ovaries. Secretion of the colleterial glands forms the hard egg case or ootheca around groups of eggs.

Streptococcus is a bacteria which is included under Kingdom Monera. Monerans have prokaryotic cell organisation in which membrane bound organelles like mitochondria, E.R., Golgi bodies, etc., are absent. All the other three i.e., Saccharomyces (a fungus), Chlamydomonas (an algae) and Plasmodium (a protozoan protist) are eukaryotes containing true membrane bound organelles.

Anaphase II of meiosis is characterized by the separation of sister chromatids, similar to anaphase in mitosis. During Anaphase I, homologous chromosomes are separated, but the sister chromatids remain attached. It is not until Anaphase II that these chromatids are finally pulled apart and move towards opposite poles, leading to the formation of haploid daughter cells.

Centrioles play a crucial role in cell division in animal cells by organizing the mitotic spindle. These cylindrical structures help in the formation of spindle fibers that separate chromosomes during cell division.

The main purpose of the G₂ phase, or Gap 2 phase, is to prepare the cell for mitosis. This phase follows DNA replication in the S phase and involves the synthesis of proteins and other components needed for cell division. It ensures that the cell is fully prepared for the complex process of mitosis, including chromosome segregation and cell division.

Both statements are correct.

Natural selection is the primary mechanism by which antibiotic resistance spreads through bacterial populations. Bacteria with mutations that confer resistance to antibiotics are more likely to survive and reproduce in the presence of antibiotics, spreading the resistance genes through the population.

Diagram showing inflammation in one of the lower limbs due to elephantiasis
Wuchereria (W. bancrofti and W. malayi), the filarial worms cause a slowly developing chronic inflammation of the organs in which they live for many years, usually the lymphatic vessels of the lower limbs and the disease is called elephantiasis or filariasis. The genital organs are also often affected, resulting in gross deformities. The pathogens are transmitted to a healthy person through the bite by the female mosquito vectors

Small branches of the renal artery give rise to afferent arterioles (afferent means to carry toward). An afferent arteriole conducts blood into the capillaries that make up each glomerulus. 

The lymphatic system primarily consists of lymphatic vessels, which are similar to the veins of the circulatory system. The vessels are connected to lymph nodes, where the lymph is filtered. The tonsils, adenoids, spleen and thymus are all part of the lymphatic system. Lymph vessels possess valves, like veins, to prevent backflow. Lymphatics actually have more valves than veins.

Using Agrobacterium vectors, nematode-specific genes were introduced into the host plant. The introduction of DNA was such that it produced both sense and anti-sense RNA in the host cells. These two RNA’s being complementary to each other formed a double stranded (dsRNA) that initiated RNAi and thus, silenced the specific mRNA of the nematode

The sympathetic nervous system stimulates the release of hyperglycemic hormones like adrenaline. These hormones helps in the breakdown of glycogen form glucose by a process called glycogenolysis and hence increases the level of glucose in the blood.

Association between roots of higher plants, e.g., pine, birch and fungal hyphae is called mycorrhiza. It exhibits the phenomenon of symbiosis. Here both the organisms in association are mutually benefitted. In this, fungal hyphae take nutrition from the plant and in return increase surface area for absorption of water and minerals for the plant.

The primary role of the rough endoplasmic reticulum (RER) is protein synthesis. The RER is studded with ribosomes, which are sites of protein synthesis. Newly synthesized proteins are threaded into the RER where they can be modified and folded properly.

Cardiac muscle resists fatigue so well because it's got more mitochondria than skeletal muscle. With so many power plants at its disposal, the heart doesn't need to stop and chill out. It also has a steady supply of blood bringing it oxygen and nutrients.