General Biology: Anatomy and Physiology

Comprehensive flashcards covering cell biology, plant physiology, animal tissues, and human systems based on lecture notes.

How is 'tissue' defined in multicellular organisms?

A group of similar cells along with intercellular substances that perform a specific function.

What was the significance of the cell theory proposed by Schleiden and Schwann?

It emphasized the cellular organization of all life forms, though it initially did not explain how new cells were formed.

What contribution did Rudolf Virchow make to the cell theory in 1855?

He provided the explanation Omnis\,cellula-e\,cellula, meaning that all cells arise from pre-existing cells.

What are the two major phases of the cell cycle?

The Interphase (representing the phase between two successive M phases) and the M Phase (Mitosis phase).

What are the sub-phases of Interphase?

The G1 phase (Gap 1), S phase (Synthesis), and G2 phase (Gap 2).

What occurs during the S phase of the cell cycle?

DNA replication or synthesis takes place; the amount of DNA per cell doubles, but the chromosome number remains the same.

Define mitosis and its primary significance.

A type of cell division resulting in two daughter cells with identical genetic complement to the parent; it is essential for growth and cell repair.

How does meiosis differ from mitosis regarding chromosome number?

Meiosis is a reduction division that reduces the chromosome number by half, resulting in the production of haploid daughter cells (gametes).

What are the four components of xylem in angiosperms?

Tracheids, vessels, xylem fibres, and xylem parenchyma.

What is the function of the phloem?

To transport food materials, usually from leaves to other parts of the plant.

Define 'transpiration'.

The evaporative loss of water by plants, occurring mainly through the stomata in the leaves.

What are the three main types of animal tissues?

Epithelial, Connective, Muscular, and Neural tissues.

What is the function of 'tight junctions' in animal tissues?

They help to stop substances from leaking across a tissue.

Describe the structure of human hemoglobin (Hb).

It is a quaternary structure consisting of four subunits: two \alpha type and two \beta type chains.

What are the three stages of the Calvin Cycle in photosynthesis?

Carboxylation, Reduction, and Regeneration of the CO_2 acceptor (RuBP).

What is the 'Respiratory Quotient' (RQ)?

The ratio of the volume of CO2 evolved to the volume of O2 consumed during respiration.

What are the primary functions of the human kidney?

Excretion of nitrogenous wastes and osmoregulation (maintenance of ionic and acid-base balance).

What is the purpose of the 'Counter Current Mechanism' in the kidney?

To produce a concentrated urine by maintaining a concentration gradient in the medullary interstitium.

Define 'Photoperiodism'.

The response of plants to the relative lengths of day and night to induce flowering.

What is the function of the hormone Insulin?

It is a peptide hormone that plays a major role in regulating glucose homeostasis by enhancing cellular glucose uptake and utilization.