B1 Biology: Cells, Body Systems, and Reproduction Flashcards

Comprehensive vocabulary flashcards covering the 'Biology B1' chapters on cells, body systems, and plant/animal reproduction.

Organism

The scientific name for all living things.

Cell

The building blocks of life and the smallest units found in an organism.

Microscope

A piece of equipment that magnifies images using lenses to observe very small objects in detail.

Observation

The act of looking carefully and in detail at an object.

Total magnification

$$\text{eyepiece lens magnification} \times \text{objective lens magnification}$$

Nucleus

The component of a cell that controls its activities and contains genetic material.

Cell membrane

A barrier around the cell that controls which substances can move in and out.

Cytoplasm

A jelly-like substance inside a cell where chemical reactions take place.

Mitochondria

The part of the cell where respiration takes place to transfer energy.

Respiration

A special type of chemical reaction that transfers energy for the organism.

Cell wall

A rigid outer layer in plant cells made of cellulose that strengthens the cell and provides support.

Vacuole

A plant cell component containing cell sap that keeps the cell firm.

Chloroplast

The component in plant cells where photosynthesis happens; it contains the green substance chlorophyll.

Photosynthesis

The process by which plants make food using energy transferred from the Sun.

Specialised cell

A cell with a specific shape and structure suited to carrying out a particular job.

Adaptations

The shape and special features of a specialised cell that help it perform its function.

Nerve cell

A long, thin cell (also called a neurone) that carries electrical impulses around the body.

Red blood cell

A cell that transports oxygen; it contains haemoglobin, has no nucleus, and has a disc-like shape to increase surface area.

Sperm cell

The male gamete, featuring a streamlined head and a long tail to move through liquids.

Egg cell

The female gamete, which has a jelly layer to protect it and attract sperm.

Root hair cell

A specialised plant cell that absorbs water and nutrients from the soil using a large surface area.

Diffusion

The movement of particles from a place of high concentration to a place of low concentration.

Concentration

The number of particles of a substance present in a specific volume or space.

Unicellular organism

An organism made up of only one single cell.

Amoeba

A unicellular organism with no fixed shape that lives in water or soil and moves by changing its body shape.

Binary fission

A form of reproduction where a single-celled organism splits into two identical cells.

Euglena

A microscopic unicellular organism found in fresh water that contains chloroplasts for photosynthesis.

Flagellum

A tail-like structure on a euglena that spins like a propeller to help it swim towards light.

Gas exchange

The transfer of gases, such as oxygen and carbon dioxide, between an organism and its environment.

Alveolus

A tiny air sac in the lung where gas exchange takes place.

Inhale

The process of breathing in to take oxygen into the body.

Exhale

The process of breathing out to remove carbon dioxide from the body.

Diaphragm

A sheet of muscle at the bottom of the chest that contracts and relaxes to aid breathing.

Lung volume

The total amount of air that the lungs can hold.

Skeleton

The framework of bones that supports the body, protects organs, helps movement, and makes blood cells.

Bone marrow

A soft tissue found in the middle of some bones that produces red and white blood cells.

Joint

A place where two or more bones join together.

Ligament

A type of tissue that holds two or more bones together at a joint.

Cartilage

A strong, smooth tissue covering the ends of bones in a joint to prevent them from rubbing together.

Newton (N)

The standard unit used to measure force, including muscle strength.

Tendon

Tissue that attaches muscles to bones.

Antagonistic muscles

A pair of muscles that work together at a joint; when one contracts, the other relaxes.

Adolescence

The period of time during which a person changes from a child to an adult involving emotional and physical changes.

Puberty

The physical changes that take place in the body during adolescence.

Sex hormones

Chemical messengers produced in the ovaries or testes that trigger the changes of puberty.

Semen

The mixture of sperm cells and nutritious fluid released from the male reproductive system.

Gametes

Reproductive cells, such as the sperm cell in males and the egg cell in females.

Fertilisation

The process where the nucleus of a sperm cell and the nucleus of an egg cell join together.

Embryo

A ball of cells formed from a fertilised egg that has divided several times.

Implantation

The process where an embryo attaches to the lining of the uterus to begin developing into a baby.

Gestation

The time from fertilisation until birth, also known as pregnancy; it takes approximately $40$ weeks in humans.

Placenta

An organ that allows oxygen and nutrients to diffuse from the mother's blood to the foetus' blood.

Umbilical cord

The structure that connects the foetus to the placenta.

Foetus

The name given to a developing human embryo after $8$ weeks of growth.

Menstrual cycle

A monthly sequence lasting about $28$ days where the uterus lining breaks down if an egg is not fertilised.

Ovulation

The release of a mature egg cell from one of the ovaries, typically occurring on Day $14$ of the menstrual cycle.

Contraception

Methods used to prevent pregnancy, such as condoms or the contraceptive pill.

Pollination

The transfer of pollen from the anther of a flower to the stigma.

Stamen

The male reproductive part of a flower, consisting of the anther and filament.

Carpel

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

Germination

The process when a seed starts to grow, requiring water, oxygen, and warmth.

Seed dispersal

The process of moving seeds away from the parent plant to reduce competition for resources.