SL IB Biology 1 Semester 2 Exam Review

Flashcards for SL IB Biology 1 Semester 2 Exam Review

ATP

Molecule that distributes energy within cells consisting of adenine, ribose, and three phosphate groups.

Properties of ATP

Releases energy immediately, is small and soluble, easily regenerated from ADP, and releases a small manageable amount of energy.

Movement (ATP)

Muscle contraction (actin-myosin interaction).

Synthesis (ATP)

Protein synthesis in ribosomes.

Transport (ATP)

Active transport of ions via Sodium-Potassium pumps.

ATP Structure and Function

Consists of 3 phosphate groups; the bond between the second and third phosphate group is broken via hydrolysis, producing ADP and free phosphate, which powers cellular processes

Anaerobic Respiration

No oxygen, glucose substrate, lactic acid or ethanol + CO2 waste, 2 ATP yield, energy without oxygen, temporary, less efficient, occurs in the cytoplasm, no organelles used.

Aerobic Respiration

Uses oxygen, glucose substrate + oxygen, CO2 + H2O waste, 36-38 ATP yield, energy production, occurs in the cytoplasm and mitochondria, mitochondria organelle used.

Factors that increase cell respiration

Higher temps, increased glucose availability, more oxygen levels, higher enzyme concentration.

Factors that decrease cell respiration

Low temperature and low oxygen or glucose availability

Photosynthesis Equation

6CO2 + 6H2O --> C6H12O6 + 6O2

Hydrogen Use in Photosynthesis

Hydrogen from photolysis is used during light-independent reactions (Calvin cycle) to reduce CO2 and form glucose.

Oxygen Production in Photosynthesis

Oxygen is produced during the photolysis of water in the light-dependent reactions of photosynthesis.

Photosynthetic Pigments Separation

The pigments present in chloroplasts can be determined by separating them using chromatography.

Molecular structure of pigment

Determines the specific light energy they can absorb.

Dependent variables to determine rate of photosynthesis

Oxygen production & Carbon dioxide uptake.

Absorption spectrum

Shows the wavelength of light absorbed by a pigment.

Action spectrum

Shows the effectiveness of different wavelengths in photosynthesis.

Light Absorption and Photosynthesis Rate

The more light absorbed by pigments, the higher the rate of photosynthesis.

Methods for Carbon Dioxide Enrichment Experiments

Burning fossil fuels releases CO2 into the air; CO2 tanks or cylinders - controlled release into enclosed environments.

Waxy cuticle adaption in leaves

Prevents water loss, allows light to pass.

Palisade mesophyll adaptation in leaves

Tightly packed with many chloroplasts, maximizing light absorption.

Spongy mesophyll adaptation in leaves

Loosely packed with air spaces for gas diffusion.

increased Light effect on rate of transpiration

Stomata open in light, allowing water vapor to escape.

Increased temperature effect on rate of transpiration

Warmer air increases evaporation and diffusion of water from leaves.

Increased wind speed effect on rate of transpiration

Removes humid air from around the leaf, increasing the diffusion gradient.

Increased humidity effect on rate of transpiration

Reduces the water vapor concentration gradient, slowing transpiration.

Correlation between atmospheric carbon dioxide concentrations and stomatal density

Higher CO2 means plants don't need as much stomata to absorb CO2, reducing water loss while maintaining gas exchange.

Role of capillary action in cohesion-tension theory

Water rises through xylem vessels due to adhesion and cohesion.

Resulting pressure in cohesion-tension theory

Transpiration creates a negative pressure in the xylem.

Resulting movement of water in cohesion-tension theory

Water is pulled into the leaves.

Role of cohesion in cohesion-tension theory

Hydrogen bonds form between water molecules that allow more water to be pulled up through the xylem.

Lack of cell contents and incomplete/absent end walls

Can reduce resistance to water flow.

Lignified cell walls

Can provide strength and prevents collapse under tension created by transpiration.

Pits in the sidewalls

Allows lateral movement of water between the vessels and tissues.

What is formed when the male pollen fertilizes the female gamete in a flower?

A zygote

Steps from pollination to development of the embryo.

Pollen lands on stigma pollen tube grows down the style Sperm travels to ovule in Ovary Fertilization occurs > Zygote forms> develops into embryo inside seed.

Petals

Large, colorful, attract insects

Scent

Sweet smell, lure insects

Pollen grains

Sticky to attach to insects.

Stigma

Sticky to catch pollen from insects

Nectaries

Produce nector

Cross-pollination

Transfer of pollen from one plant to another plant.

Hermaphrodite

On organism that has male & female reproductive organs.

Hybrid vigor

Hybrid offspring exhibits greater vigor and productivity compared to its Purebread parent lines.

Protandry

Males arriving or emerging before Females in seasonal population

Protogyny

A reproductive strat where females Structures mature before make structures.

For pollination to occur, should the alleles be the same or different between the pollen parent and pistil?

They must be different

What is the advantage of self-incompatibility?

Increases genetic diversity, more adaptable to changing environments and potentially less susceptible to diseases.

What is the term to describe when Pollen is moved from a flower on one plant to a flower on a different plant?

Cross pollination- the process where pollen is transferred from the male part (anther) of one plant to the female part (stigma) of another plant, usually of the same species.

Advantages of seed dispersal

Reduces competition, allows plants to colonize new areas, avoid predation.