Science unit

Circulatory System

Made up of blood vessels that carry blood to and from the heart.

Arteries

Blood vessels that carry blood away from the heart.

Veins

Blood vessels that carry blood back to the heart.

Cardiac Output

The amount of blood the heart pumps in one minute, calculated by multiplying stroke volume by heart rate.

Left Atrium

Upper chamber of the heart that receives oxygenated blood from the lungs.

Right Atrium

Upper chamber of the heart that receives deoxygenated blood from the body.

Tricuspid Valve

Valves that control blood flow from the right atrium to the right ventricle.

Pulmonary Valve

Valves that control blood flow from the right ventricle to the lungs.

Left Ventricle

Lower chamber of the heart that pumps oxygenated blood to the body.

Aorta

The largest blood vessel in the body, transporting oxygenated blood from the heart.

Coronary Arteries

Arteries that supply oxygen-rich blood to the heart muscle.

Superior Vena Cava

Vein that brings deoxygenated blood from the upper body to the heart.

Inferior Vena Cava

Vein that carries deoxygenated blood from the lower body to the heart.

Capillaries

Small blood vessels where exchange of gases, nutrients, and wastes occurs.

Blood Pressure

The pressure of circulating blood on the walls of blood vessels.

Factors Affecting Heart Rate

Age, health conditions, fitness, and physical activities.

Varicose Veins

Enlarged veins caused by weakened valves and improper blood flow.

White Blood Cells

Cells in the blood that help fight infections.

Red Blood Cells

Cells that carry oxygen from the lungs to the body's tissues.

Platelets

Cell fragments that help in blood clotting.

Atherosclerosis

blood vessel disease. A condition where fatty deposits build up in the arteries plaque. Plaque hardens overtime and narrows your arteries. Limiting blood flow of oxygenated blood to your body.

Angina

Chest pain caused by reduced blood flow to the heart.

Plaque Buildup

Accumulation of fats and cholesterol in the walls of arteries.

Immune System

The body's defense against infections.

Physical Barriers

First line of defense, including skin and mucous membranes.

Innate Immunity

Non-specific defenses that respond to pathogens immediately.

Adaptive Immunity

Specific defenses that target particular pathogens.

Macrophages

White blood cells that engulf and digest pathogens.

Helper T Cells

Cells that activate other immune cells and coordinate the immune response.

Antibodies

Proteins produced by B cells that bind to antigens.

Cytotoxic T Cells

Cells that attack and destroy infected or cancerous cells.

Memory B Cells

Long-lived B cells that remember past pathogens for quicker response.

Autoimmune Disease

A condition where the immune system mistakenly attacks its own cells.

Chromosomes

Thread-like structures made of DNA found in the nucleus of cells.

Karyotyping

A laboratory technique used to examine chromosomes for genetic abnormalities.

Down Syndrome

A genetic disorder caused by an extra copy of chromosome 21.

Mitosis

Cell division resulting in two identical daughter cells.

Meiosis

Cell division that produces four genetically unique gametes.

Fertilization

The union of sperm and egg to form a zygote.

Selective Breeding

Choosing specific parents with desirable traits for offspring.

Dominant Gene

A gene that expresses its trait when present.

Recessive Gene

A gene that is expressed only when two copies are inherited.

Homozygous

An individual with two identical alleles for a trait.

Heterozygous

An individual with two different alleles for a trait.

Phenotype

The physical expression of an organism's genotype.

Genotype

The genetic makeup of an organism.

Sex-linked Traits

Traits associated with genes located on the sex chromosomes.

DNA

Molecule that carries genetic information, structured as a double helix.

Nucleotides

Building blocks of DNA, consisting of sugar, phosphate, and nitrogenous base.

Protein Synthesis

Process by which cells create proteins, involving transcription and translation.

Cystic Fibrosis

A genetic disorder affecting the lungs and digestive system.

Point Mutations

Changes in a single nucleotide in the DNA sequence.

Pedigree Charts

Diagrams showing familial relationships and inheritance patterns of traits.

Gene Therapy

A technique aimed at treating genetic disorders by modifying genes.

arteries characteristics

carry oxygen-rich blood away from the heart

• Thick, muscular walls to withstand high pressure from the heart’s pumping action.

  • Elastic fibers that allow the arteries to stretch as blood is pumped through.

  • Small diameter (but larger than veins).

  • No valves (because the pressure from the heart keeps the blood moving forward).

veins characteristics

• Thinner walls than arteries because the blood pressure in veins is much lower.

  • Valves to prevent blood from flowing backward due to low pressure and gravity (important in legs and arms).Veins carry blood back to the heart, and they have one-way valves that help ensure blood flows upward, especially from the legs, against gravity.

capilaries charctersitics

• the smallest blood vessels, where the exchange of oxygen, carbon dioxide, nutrients, and waste products occurs between the blood and tissues.

  • Very thin walls (just one cell thick) to allow easy exchange of gases and nutrients.

  • Extremely small diameter, allowing red blood cells to pass through in a single file.

  • No valves.

Immune system respond to invaders

Before the immune system even needs to respond to an invader, the body has physical and chemical defences:

• Skin,Mucous Membranes, Stomach Acid, (White Blood Cells): These are the first responders to an infection.

• Macrophages and neutrophils are types identify pathogens, and engulf (consume) them. Antigens: When a pathogen enters the body, it has molecules on its surface called antigens. These act as "identifiers" that the immune system uses to recognize and target the pathogen.

  • Helper T Cells: These cells are like commanders that help coordinate the immune response. They activate B cells to produce antibodies and stimulate killer T cells to attack infected cells.

    • Cytotoxic T Cells (Killer T Cells): These cells directly attack and kill infected cells or cancerous cells by releasing enzymes that cause the infected cells to self-destruct.

  • B Cells (B Lymphocytes): These cells produce antibodies (also called immunoglobulins). Antibodies are proteins that specifically recognize and bind to antigens on the surface of pathogens, marking them for destruction.

  • Antibodies: These proteins are designed to bind to the antigen of a pathogen. This binding marks the pathogen for destruction by other immune cells (like macrophages) or neutralizes its ability to cause harm (such as preventing a virus from entering a cell).
    The immune system has a memory that allows it to respond more efficiently if the body is exposed to the same pathogen again. This is the basis for immunity and why vaccines are effective:

  • memory B cells. If the body encounters the same pathogen again, these cells can rapidly produce the appropriate antibodies to fight off the infection.

Memory T Cells: Similarly, memory T cells "remember" pathogens and can quickly recognize and destroy infected cells if
they encounter the same pathogen in the future.

what are protist

single-celled organisms . Some are parasites, meaning they live and reproduce inside a host, making them difficult for the immune system to eliminate.

how can protist spread across the body

can enter the body through contaminated water or food, mosquito bites or direct contact with infected feces.

• Once inside, they invade cells or tissues, using the body's nutrients to grow and multiply.

• Some, hide inside red blood cells, making it harder for the immune system to detect them.

How does the immune system respond to Protist

• Macrophages and Neutrophils try to engulf and destroy

• Inflammatory responses help slow down the infection.

• T cells and B cells create a specific response by producing antibodies to target the.

Some _, constantly change their surface proteins to evade immune detection, making them difficult to eliminate.

Fungi

multicellular or single-celled organisms that can cause infections like athlete’s foot, yeast infections (Candida), and lung infections

how does fungi spread in the body

• Skin contact: Fungal infections like athlete’s foot spread through contact with contaminated surfaces.

• Inhalation: leading to respiratory infections.

Overgrowth of normal fungi: Some fungi, like Candida, are normally present in the body but can grow uncontrollably if the immune system is weak.

Viruses

Viruses are non-living infectious agents that invade host cells, hijack their machinery, and force them to create more viruses.

how viruses spread through the body

• Through the air

• By direct contact (HIV).

• Through insect bites (Zika virus).

By contaminated surfaces (cold viruses).

how does the immune system respond to a virus

• Natural Killer (NK) Cells: These cells destroy virus-infected cells before the virus can spread.

• T Cells:

  • Helper T Cells activate other immune responses.

  • Cytotoxic (Killer) T Cells attack and destroy infected cells.

• B Cells and Antibodies: Antibodies bind to viruses and prevent them from infecting more cells.

Some viruses, like HIV, attack and weaken the immune system by directly targeting T cells, making the body vulnerable to other infections.

chromosomes where are they located?

thread-like structures made of DNA and proteins that carry genetic information.Found inside the nucleus of the cell. Humans have 46 (23 pairs) in most body cells.

Karotyping

 A laboratory technique used to examine an individual's chromosomes to detect genetic abnormalities. It involves arranging and analyzing chromosomes based on their size, shape, and number.Chromosomes are arranged in pairs (from largest to smallest) to form a karyotype chart. Scientists check for extra, missing, or abnormal chromosomes.

what do genetic disorders look like

These disorders involve missing, extra, or altered chromosomes:

Plasmids

small pieces of dna that exist separating from the bacterial chromosomes. Often carrying genes that provide antibiotic resistance that bacteria can transfer to other conjugation.Now, multiple bacteria carry resistance genes and can survive the antibiotic.Over time, resistant bacteria multiply, making the antibiotic less effective.

fertilization

 the process where a sperm cell (male gamete, haploid) and an egg cell (female gamete, haploid)combine to form a zygote (diploid), restoring the full number of chromosomes. Sperm Cell (n = 23 chromosomes) → Carries either an X or Y chromosome (determines biological sex). Egg Cell (n = 23 chromosomes)→ Always carries an X chromosome. When they fuse, the zygote has 46 chromosomes (diploid, 2n).

self pollination

• involves the fusion of gametes from the same plant, meaning the offspring inherit identical or very similar chromosomes.

• Over generations, this can lead to genetic uniformity, making plants more vulnerable to environmental changes or diseases.

Because no new chromosome combinations are introduced, self-pollinated plants may show less variation in traits.

cross pollination

leads to greater genetic variation because chromosomes from two different parent plants combine.

• During fertilization, each parent contributes half of its chromosomes, resulting in offspring with a unique genetic makeup.

• This genetic diversity helps plants adapt to changing environments and develop resistance to diseases.

• Since different alleles (gene variations) mix, cross-pollination can produce plants with new and improved traits.

A. dominant gene

a gene that expresses its trait even if only one copy is present. It overpower the effect of a recessive gene when both are inherited.

Recessive gene

A recessive gene is a gene that is only expressed when an individual inherits two copies of it (one from each parent). If a dominant gene is present, the recessive gene is hidden and does not show its effect. (Homozygous aa)

Homozygous

when they inherit two identical alleles for a particular gene (either both dominant or both recessive).

Heterozygous

when they inherit two different alleles for a particular gene, one dominant and one recessive.

One dominant allele (A) and one recessive allele (a) (e.g., for brown eyes, where B = brown and b = blue, an individual with Bb would have brown eyes).

X-linked traits

Since males only have one X chromosome, they either express the trait (if they inherit the affected gene) or do not have it at all. In females, the presence of a second X chromosome can sometimes "mask" the effects of a defective gene in X-linked recessive traits.

Genotype

• The genetic makeup of an organism, referring to the specific combination of alleles inherited from both parents.
  

Phenotype

The physical appearance or traits of an organism that are expressed as a result of the interaction between its genotype and the environment.

Nucleotides in DNA

1. • Each strand of DNA is made up of _, which consist of:

     • Sugar (Deoxyribose) – Provides structure.

     • Phosphate Group – Connects nucleotides together.

Nitrogenous Base – Carries genetic information.

transcrption

•  Copy the recipe (DNA) onto a piece of paper (mRNA).

Translation

• Use the recipe (mRNA) to cook the dish (protein) in the kitchen (ribosome).

Recombinant DNA

Recombinant DNA (rDNA) is artificially created DNA that combines genetic material from two or more different sources. This is done by cutting and joining DNA from different organisms using biotechnology techniques.

Pulmonary circulationt

to the lungs to pick up oxygen

Systematic circulation

To pick up oxygen in the rest of the body with nutients too.

Left atrium contraction

Forces the blood into left ventricle, the heart most muscular chamber

Right Atrium contraption

forces blood into the right ventricle

Right Ventricle contraction

Forces the blood to flow out of the heart and into the right and left lungs; at the lungs, the blood undergoes releasing carbon dioxide waste product of cell activity.

Left Ventricle Contraction

Forces blood into the aorta and through many branches directing oxygen rich blood to the entire body

Contraction of skeletal muscles

Moves blood back to the heart muscle squeezes the veins which increases the pressure and forces blood to flow towards the heart

Direction of blood flow

Arteries- carry blood, away from the heart. Veins-carry blood towards the heart.

Ventricular systole

Atria in contraction a valves are open and blood to ventricles

Ventricular Diastole

All heart muscles are in relaxation . All heart valves are closed.

Bacteria

microscopic single celled organisms that doesnt have a nucleus. causes leprosy

Virus

Non cellular non living particles that replicate in host cells. causes colds, flus

4 main functions of the circulatory system

Transports, delivers oxygen and nutrients in exchange for carbon dioxide and waste . 2) delivers chemical messages. 3) Distributes body heat. 4) Defends against disease