life sciences notes

What is mitosis?

A type of cell division where a single parent cell divides to produce two genetically identical daughter cells.

What are the primary functions of mitosis?

Growth, repair and replacement, and asexual reproduction.

What are the phases of the cell cycle?

Interphase (G1, S, G2 phases) and M-phase (mitotic phase).

In what phase does DNA replication occur?

S Phase (Synthesis) of Interphase.

What happens during prophase?

Chromatin condenses into visible chromosomes; nuclear envelope breaks down; spindle fibers form.

How do chromosomes align in metaphase?

Chromosomes align along the equatorial plate of the cell.

What occurs during anaphase?

Sister chromatids are pulled apart and move toward opposite poles.

How does cytokinesis differ between animal and plant cells?

Animal cells form a cleavage furrow; plant cells form a cell plate.

What is a benign tumor?

A tumor that remains localized and does not invade neighboring tissue.

What is a malignant tumor?

A tumor that invades adjacent tissues and can metastasize.

What is the chemical equation for photosynthesis?

$6CO_2 + 6H_2O \rightarrow C_6H_{12}O_6 + 6O_2$.

What are the two phases of photosynthesis?

Light-dependent phase and light-independent phase (Calvin cycle).

What occurs in the light-dependent phase of photosynthesis?

Chlorophyll absorbs radiant energy and splits water molecules, producing ATP and NADPH.

What is the chemical equation for aerobic respiration?

$C_6H_{12}O_6 + 6O_2 \rightarrow 6CO_2 + 6H_2O + 36\text{ to }38 ATP$.

Where does glycolysis occur?

In the cytoplasm (cytosol).

What is the outcome of alcoholic fermentation?

$\text{Glucose} \rightarrow 2 \text{Ethanol} + 2CO_2 + 2 \text{ATP}$.

What are the essential digestive processes?

Ingestion, digestion, absorption, assimilation, and egestion.

What is the function of alveoli?

Site of gas exchange in the lungs.

What are the six requirements of an efficient gaseous exchange surface?

Large surface area, thin diffusion barrier, moist surface, well ventilated, highly vascularized, and well protected.

What is the role of nicotine in tobacco smoke?

An addictive stimulant that constricts blood vessels and elevates heart rate.

How does smoking affect the respiratory system?

Causes chronic bronchitis, emphysema, and lung cancer.

What is the relationship between photosynthesis and cellular respiration?

Products of one process serve as substrates for the other, forming a cyclical relationship.