Free Growth and Development MCQs with Answers

21. Tails can be regenerated in:

• A. The larvae of amphibians
• B. Lizards
• C. Both lizards and the larvae of amphibians
• D. None of these

Explanation: Lizards possess the ability to regenerate a cartilage rod and associated tail from an already regenerated portion of their tail, after a shearing event through the cartilage rod, such as a bite from a predator. Various research papers suggest larvae also possess this ability.

22. Germ cells give rise to:

• A. Legs
• B. Head
• C. Eggs and sperms
• D. Hands
• E. All body parts

Explanation: There are two types of human germ cells, eggs, and sperms.

23. When a fetus is in the uterus, what carries oxygen away from the placenta?

• A. The amniotic fluid
• B. The amniotic sac
• C. The lining of the uterus
• D. The umbilical cord

Explanation: The umbilical cord contains umbilical vessels, arteries, and veins. The umbilical veins take oxygen away from the placenta to the fetus.

24. Germ layers are formed in which stage of development?

• A. Morulation
• B. Blastulation
• C. Gastrulation
• D. Organogenesis

Explanation: Germ layers that are ectoderm, endoderm, and mesoderm are formed during gastrulation. During gastrulation, the blastoderm splits into two layers: an upper layer of cells called epiblast and a lower layer of cells called hypoblast. The epiblast is the presumptive ectoderm and mesoderm while the hypoblast is the presumptive endoderm.

25. Innermost microsporangial wall layer that nourishes pollen grains is:

• A. Endothecium
• B. Tapetum
• C. Endodermis
• D. Sporogenous tissue

Explanation: The microsporangial wall comprises four layers: Epidermis, Endothecium, Middle layers and Tapetum. The epidermis is followed by a single layer of endothecium, 2-3 middle layers and a single layer of tapetum. Epidermis functions as a protective covering.Endothecium develops fibrous thickenings at maturity, which are hygroscopic in nature and helps in anther dehiscence.Middle layers are involved in the storage of reserve food material during early stages of microspores development which later get mobilized to the developing microspores.Tapetum is the innermost layer of the anther wall and surrounds the sporogenous tissue completely. It provides nutrition to the developing microspores which form the pollen grains.Hence, the innermost microsporangial wall that nourishes pollen grains is tapetum. So, the correct answer is B.

26. The major sign and symptoms of microcephaly is:

• A. Sexual defects
• B. Excessive number of toes
• C. Mental retardation
• D. Small skull in proportion to the normal body size
• E. Split in upper lip and gap in the roof of mouth

Explanation: Microcephaly is a neurological condition in which a baby's head is much smaller than expected for the baby's age. The head circumference is typically below the third percentile for the baby's sex and age. Microcephaly can be caused by a variety of genetic and environmental factors, and it can be associated with a range of developmental disabilities.

27. Microcephaly, the small sized skull is due to:

• A. Nutritional causes
• B. Skeletal causes
• C. Hormonal causes
• D. Genetic defects

Explanation: Microcephaly is a condition where the head (circumference) is smaller than normal. Microcephaly may be caused by genetic abnormalities. Genetic mutations in various genes can disrupt brain development and cause microcephaly. Some well-known genetic syndromes associated with microcephaly include Down syndrome, Apert syndrome, and Seckel syndrome.

28. The most abundant organic molecule on the planet earth is:

• A. Starch
• B. Glycogen
• C. Glucose
• D. Cellulose

Explanation: The most abundant organic molecule on the planet Earth is cellulose. Cellulose is a polysaccharide, or carbohydrate, that is made up of glucose monomers. It is found in the cell walls of plants and is the main structural component of plant fibers. Cellulose is also a major component of wood and cotton.

29. The active sites of all enzyme are formed by:

• A. R-groups of amino acids
• B. NH2 groups of amino acids
• C. -COOH groups of amino acids
• D. Exposed disulphide bonds

Explanation: The R group, also known as the side chain, is the part of an amino acid that determines its properties. The R groups of amino acids can be very different from each other, and they give enzymes their specificity for different substrates.

30. Cytoplasmic localization is a consequence of:

• A. Fertilization
• B. Cleavage
• C. Morula
• D. Blastula
• E. Gastrula

Explanation: Cytoplasmic localization means the unequal distribution of proteins and other components after division. This is the consequence of actual cell division(cleavage). It is a complex process that is essential for regulating cellular functions. By controlling the distribution of molecules within the cytoplasm, cells can ensure that the right molecules are in the right place at the right time.