Biology Test - 2 Grade IX CBSE

Xanthophylls are yellow, orange, and red pigments belonging to the carotenoid family. They become visible when chlorophyll degrades (autumn leaf color). Chlorophyll is green. 'Leucophyll' is not a standard term - white pigments are typically chromoplasts without pigment. Erythrophyll is not standard botanical terminology.

Leucoplasts are non-pigmented plastids found in plant cells that specialize in the storage of starch (amyloplasts), lipids (elaioplasts), or proteins (proteinoplasts). Chloroplasts are green and used for photosynthesis.

Osmosis is the movement of solvent molecules through a semi-permeable membrane from a region of lower solute concentration to a region of higher solute concentration.

The tonoplast is the cytoplasmic membrane that surrounds the vacuole of a plant cell, separating the vacuolar contents from the cytoplasm.

Genes are segments of DNA that are organized into structures called chromosomes, which are located within the nucleus of eukaryotic cells.

Lysosomes are single-membrane-bound organelles containing digestive enzymes. Mitochondria, chloroplasts, and the nucleus are all surrounded by a double membrane.

Epithelial tissue (epithelium) covers the body surface and lines internal organs and cavities. Epidermis is a specific layer of the skin, but epithelium is the general tissue type.

A gland is a group of cells or an organ that synthesizes and secretes substances such as hormones or enzymes.

Chondrocytes are the only cells found in healthy cartilage. Osteocytes are found in bone, and erythrocytes/leucocytes are blood cells.

Fibroblasts are the most common cells in connective tissue and are responsible for producing the extracellular matrix and collagen fibers.

A ligament is a fibrous connective tissue that connects bone to bone. A tendon connects muscle to bone.

Pseudopodia (singular: pseudopodium) are temporary protrusions of the cytoplasm used by amoeboid cells for movement and feeding, literally meaning 'false feet'.

A synapse is the junction between two neurons where nerve impulses are transmitted via neurotransmitters.

Collenchyma is a supporting tissue in plants that is often found in the hypodermis of stems and leaves, providing structural support while allowing for growth.

Diploblastic organisms develop from two germ layers: the ectoderm and the endoderm. Triploblastic organisms have three layers, including the mesoderm.

Oviparous animals are those that produce eggs that develop and hatch outside the body of the mother. Viviparous animals give birth to live young.

The thorax is the region of the body located between the head and the abdomen in animals such as insects and vertebrates.

Amino acids are the building blocks (monomers) of proteins (polymers).

ATP (Adenosine triphosphate) is the primary energy carrier molecule in all living cells.

Spongin is a fibrous protein that forms the skeletal structure of many sponges.

Meristematic cells are undifferentiated plant cells that are capable of active cell division, unlike permanent cells which have specialized and lost the ability to divide.

Iodine is essential for thyroid hormone synthesis, and these hormones regulate the body's basal metabolic rate. Iodine deficiency causes hypothyroidism, characterized by fatigue, weight gain, and slowed metabolism due to reduced thyroid hormone production. The question contains a minor typo ("metabolilsm").

Soybeans are widely recognized as a high-quality plant-based source of protein. They contain all essential amino acids, making them a complete protein source.

Anemia is a medical condition characterized by a deficiency of red blood cells or hemoglobin in the blood. This reduces the oxygen-carrying capacity of the blood, leading to fatigue and weakness.

Necrosis refers to the premature death of cells in living tissue caused by external factors such as infection, toxins, or trauma. It is distinct from apoptosis, which is programmed cell death.