Living Environment Regent's Review

Topic 1: Matter and energy in organisms and ecosystems

Photosynthesis:

Co2+Water+Sunlight = O2 and Glucose

Happens in the chloroplast

Main purpose is to produce glucose

Happens in plants, bacteria, algae

Cellular Respiration: O2+Glucose = C02+Water+ATP (energy)

Happens in the cytoplasm and mitochondria

Main purpose is to produce energy

Happens in all living things

Aerobic uses oxygen

Anaerobic does not use oxygen

Gas exchange: Take in O2 release Co2

🌿 Energy comes from the Sun → used by producers (plants) → passed to consumers → then to decomposers.

Energy is lost as heat at each level (not recycled).

Use food chains and food webs to show energy flow.

Topic 2: Structure and Function

Cells: The building blocks of life

Organelles: Carry out the cell’s work

Prokaryotic cells: Bacterial cells

They are small, circular, and limited organization

Cell types: Bacteria

Eukaryotic cells: are cells that have a nucleus and membrane-bound organelles.

They are large, complex and have more structure and internal organization

Cell types: Animal Cells, Plant cells, Fungal cells

Animal Cell: Circular, no chloroplast and cell wall

Plant Cell: Boxier, eukaryotic cells

Diffusion: Gases move passively across the gas exchange surface in areas of higher concentration to lower concentration

Active Transport: ATP needed, Low to high concentration

Passive Transport: No ATP needed, High to low, osmosis and diffusion

Facilitated Diffusion: Involves helper proteins

Simple Diffusion: Moves directly across a membrane

Neither require energy

Osmosis: Diffusion of water

Homeostasis: Constant state

Negative feedback: is a process the body uses to keep things stable.

Positive feedback: When a change triggers a response that intensifies a change, moving the system further away from its normal state (Childbirth, blood clotting)

Transpiration: Provides a constant supply of water needed for essential life processes

Enzymes: Break down single substrates and speed up reaction rates

Enzymes have a set of conditions: PH and temperature

If these conditions are affected, it can lead to loss of function and is called denaturation

Optimum temperature: where enzyme activity is the greatest

Topic 3: Interdependent relationships in ecosystems

Biotic factors: All living organisms

(Plants, animals, fungi, protists, and microorganisms)

Abiotic factors: Non-living physical factors

(Soil, water, atmosphere, temperature, sunlight - SWAT)

The components of an ecosystem are linked by nutrient cycles and energy flows

Evolution: The change in inherited characteristics in a population over generations

Natural Selection: The process where organisms with traits that help them survive and reproduce are more likely to pass those traits to their offspring.

Food chain: Shows how energy and matter pass from one organism to another

Producer>Primary Consumer>Secondary Consumer>Tertiary Consumer
ENERGY IS LOST AT EACH LEVEL

Decomposers: break down dead plants or animals for nutrients for nutrient cycling

Topic 4: Inheritance and variation of traits

Mitosis: The Parent cell divides into two to produce two genetically identical daughter cells

DOES NOT RESULT IN CHANGE OF CHROMOSOME NUMBER
Stem cells: Cells that can divide and make more cells or develop into different types of specialized cells

Gene: A section of DNA that codes for a protein

The molecule that transcribes the gene is RNA polymerase

Gene expression: The process of rewriting a gene into a protein

Proteins: Large molecules made up of many smaller units called amino acids joined together

It is important because it helps with structure and support, speeds up chemical reactions, and transports material

Transcription: DNA code is copied to the mRNA

Translation: Ribosomes convert an mRNA sequence into a string of amino acids that form a protein

mRNA: Messenger RNA: Brings the transcribed DNA from the nucleus to the cytoplasm

rRNA: Ribosomal RNA: Part of the ribosome where protein synthesis takes place

tRNA: Transfer RNA: carries the amino acids to the ribosome during protein synthesis

Heterozygous: An organism with two different alleles for the same trait (AA or aa)

Homozygous: An organism with two of the same alleles for the same trait (Aa)

Dominant allele: One whose trait always shows up (is expressed) in the organism when the allele is present; capital letter (AA)

Recessive allele: Not expressed whenever the dominant allele is present; lowercase letter (aa)

Variation helps organisms survive in a changing environment

Codominance: 2 alleles expressed at the same time (AB - blood type)

In complete dominance: A blending is produced

Complete dominance: dominant allele completely covers the effect of the recessive allele.

C and G pair up

A and T pair up

Topic 5: Natural selection and evolution

Natural Seletion:

Selective Breeding: is when humans choose specific animals or plants with traits they like and breed them together to get offspring with those traits.

Genetic engineering: a process that alters the DNA makeup of an organism using laboratory techniques

Topic 6: Reproduction & Body Systems

Zygote: A zygote is the first cell formed when a sperm and egg join. One single cell.

Embryo: After the zygote divides a few times by mitosis, it becomes an embryo.

The embryo has many cells and begins early development.

Fetus: In humans, after about 8 weeks, the embryo becomes a fetus.

At this stage, it starts to look more like a baby.

White Blood Cells: Engulf pathogens

Red Blood Cells: Carry fresh oxygen and remove C02

Differentiation is when cells become specialized to do specific jobs in the body. It occurs during embryonic development