Year 8 Biology Flashcards

Flashcards for Year 8 Biology covering Microscopes and Cells, Respiratory System, Circulatory System, Reproduction, and Plant Tissues and Organs.

Cell

The smallest unit of life (e.g., a lung cell).

Tissue

A group of cells working together (e.g., epithelial tissue in the lungs).

Organ

A part of the body made up of different tissues (e.g., the lungs).

System

A group of organs working together to perform a function (e.g., respiratory system).

Organism

An individual living thing made of systems (e.g., a human).

Respiration

A chemical process where oxygen is used by cells to produce energy, releasing carbon dioxide and water as by-products. Aerobic respiration occurs in the presence of oxygen.

Larynx

The voice box that contains the vocal cords.

Trachea

Windpipe; tube that carries air to the lungs.

Bronchi

Two main branches that split from the trachea into each lung.

Bronchioles

Smaller branches of the bronchi that end in alveoli.

Alveoli

Tiny air sacs in the lungs where gas exchange occurs (oxygen in, carbon dioxide out).

Lungs

Organs where gas exchange happens.

Diaphragm

A muscle below the lungs that helps control breathing.

Breathing

The process of inhaling and exhaling air.

Inspiration

Inhalation, where air is drawn into the lungs (active process).

Expiration

Exhalation, where air is pushed out of the lungs (passive process).

Heart

Pumps blood around the body.

Blood Vessels

Arteries (carry blood away from the heart), veins (carry blood to the heart), capillaries (tiny vessels where exchanges happen).

Blood

The liquid that carries oxygen, nutrients, and waste products.

Arteries

Thick-walled, carry oxygenated blood at high pressure.

Veins

Thin-walled, carry deoxygenated blood back to the heart. They have valves to prevent backflow.

Capillaries

Very thin-walled, where gas and nutrient exchange occurs (e.g., in the lungs and tissues).

Red Blood Cells (RBCs)

Carry oxygen from the lungs to the body.

White Blood Cells (WBCs)

Defend against disease.

Platelets

Help blood clot when there's an injury.

Plasma

The liquid part of blood that carries water, hormones, nutrients, and waste products.

Right Atrium

Receives deoxygenated blood from the body.

Right Ventricle

Pumps deoxygenated blood to the lungs.

Left Atrium

Receives oxygenated blood from the lungs.

Left Ventricle

Pumps oxygenated blood to the body.

Heart Valves

Ensure that blood flows in one direction.

Aorta

The largest artery in the body, carrying oxygenated blood from the heart to the rest of the body.

Asexual Reproduction

Reproduction without the need for a mate.

Sexual Reproduction

Involves the fusion of male and female gametes (sperm and egg). The offspring inherit genetic material from both parents.

Ovary

Produces eggs and hormones (estrogen and progesterone).

Fallopian Tube

Carries eggs from the ovary to the uterus.

Uterus

Where the fertilized egg develops into a baby.

Vagina

The passage through which a baby is delivered.

Testes

Produce sperm and the hormone testosterone.

Vas Deferens

Carries sperm from the testes to the urethra.

Penis

Organ for delivering sperm during intercourse.

Anther

Produces pollen (which contains sperm cells).

Filament

Supports the anther.

Stamen

Male reproductive part (anther + filament).

Stigma

The sticky surface that catches pollen.

Style

The tube through which pollen travels.

Ovary (flower)

Contains the ovules (female gametes).

Self-Pollination

Pollen from the same flower fertilizes the ovule.

Cross-Pollination

Pollen from one flower fertilizes a different flower's ovule.

Roots

Anchor the plant in soil, absorb water and nutrients.

Leaves

Photosynthesis occurs here; they produce food for the plant.

Stems

Transport water, nutrients, and sugars between roots and leaves.

Stomata

Small openings on the surface of leaves that allow gases (CO₂ in, O₂ out) and water vapor to move in and out of the plant.

Xylem

Carries water and minerals up from the roots to the leaves.

Phloem

Transports sugars produced in the leaves to the rest of the plant.

Transpiration

The process by which water evaporates from the leaves of the plant, helping to pull more water up through the roots (like a straw).

Inhalation

The action of breathing air in: diaphragm pulls down (contracts), rib cage expands.

Exhalation

The action of breathing out: diaphragm relaxes (moves up), rib cage gets smaller.

Circulatory system

The system that pumps blood around the body.

Heart

The organ that pumps blood through the circulatory system.

Atria

The smaller upper chambers of the heart.

Ventricles

The larger lower chambers of the heart.

Valves

Allows blood flow in one direction.

Capillaries

Blood vessel with a wall only once cell thick, allowing substances to easily pass into and out of the blood.

Blood

The red fluid that circulates in the arteries and veins. Contains red blood cells, white blood cells, platelets and plasma.

Red blood cells

Cells in the blood that carry oxygen around the body.

Plasma

The straw-coloured fluid that forms part of the blood.

White blood cells

Cells found in the blood that help fight infection.

Platelets

Small disc-like cells found in blood that are involved with forming clots.

Asexual reproduction

Type of reproduction not involving the fusing of gametes; where an organism can create offspring without a partner.

Sexual reproduction

Type of reproduction involving the fusing of gametes.

Gametes

Sex cell; in humans, the sperm and egg cells.

Ovary

The female organ that produces the eggs (female gamete).

Sperm

The male sex cell (gamete).

Fallopian tube

The tubes that connect the ovaries to the uterus in a female.

Vagina

An organ that is part of the female reproductive system; muscular tube connecting the outside of the female body to the cervix.

Uterus

A pear-shaped organ in the female reproductive system; where the foetus develops.

Cervix

The bottom of the uterus that forms the passage between uterus and vagina.

Testes

The male reproductive organ that produces sperm.

Vas deferens

The tube that carries sperm from the testes to the urethra; ready for ejaculation.

Penis

Male reproductive organ that delivers sperm.

Stamen

Male reproductive organ of a flower; includes the anther and filament.

Anther

Part of the stamen that contains the pollen.

Filament

Supports the anther.

Pollen

Plant male sex cells.

Carpel

The female reproductive part of a flower; includes the stigma, style and ovary.

Stigma

The male part of a flower; consists of a filament supporting an anther.

Style

Connects the stigma to the ovary; allowing the passage of pollen.

Ovary (flower)

Protective chamber that surrounds the ovules (develops into the fruit).

Ovum

Female gamete in animals.

Pollination

Process of transferring pollen from the anther to the stigma of a flower, allowing fertilisation to occur.

Xylem

Tissue in plants that transports water and minerals from the roots to the rest of the plant.

Phloem

Tissue in plants that transports the products of photosynthesis, mainly sugars, from the leaves to the rest of the plant.

Stomata

Small pores on the surface of leaves and stems that allow gas exchange and regulates water loss.

Transpiration

Process by which water is absorbed by plant roots, moves through the plant and evaporates through the stomata in the leaves.