Science exam Year 8

-Ava

Respiration definition

the action of breathing

Photosynthesis definition

The process by which plants use sunlight, water, and carbon dioxide to create oxygen and energy in the form of sugar.

Digestion definition

the breaking down of food into small molecules which are then absorbed into the body

Peristalsis definition

Peristalsis is a series of wave-like muscle contractions that move food through the digestive tract

Reproduction definition

The process of an organism generates and offspring to continue the existence of the species

asexual reproduction

reproduction from solely a single organism

Sexual reproduction

reproduction using the union of male and female reproductive cells (gametes)

Fertilisation definition

the process of fusion of the female gamete, the ovum or egg and the male gamete produced in the pollen tube by the pollen grain.

Pollination definition

The process of getting pollen from the anther to the stigma

Gamete definition

A gamete is a reproductive cell of an animal or plant

sperm cell

the male reproductive cell; the male gamete

structure: the tail, which propels the sperm to the egg and helps it to burrow through the egg coat
function: to enable sexual reproduction through its union with the female egg during fertilization

egg cell

the female reproductive cell, or gamete

structure:
function: connect with the male sperm cell in order to become fertilised and produce offspring

Red blood cell

carries oxygen from the lungs to all parts of the body.
have a flat disk shaper, which creates increased surface area to carry more oxygen

white blood cell

function: detect and deal with infections or foreign molecules that enter your body
structure:

muscle cell

structure: Each strand is made up of sub-units called "sarcomeres." These sarcomeres contain the "contraction proteins” called actin and myosin
function: Their predominant function is contractibility. Muscles, attached to bones or internal organs and blood vessels, are responsible for movement

nerve cell

The basic unit of communication in the nervous system
structure: one elongated extension (axon) for sending impulses and usually many branches (dendrites)
function: receiving impulses

gaurd cell

structure: regulating the opening and closure of stomatal pores
function: airs of epidermal cells that control gas diffusion by regulating the opening and closure of stomatal pores

trachea function

To carry air in and out of your lungs

Bronchi function

Your bronchi carry air to and from your lungs

Alveoli function

The alveoli are where the lungs and the blood exchange oxygen and carbon dioxide during the process of breathing in and breathing out

Summary Gas exchange

Oxygen moves from the lungs to the bloodstream. At the same time carbon dioxide passes from the blood to the lungs.

Stamen

The male reproductive part of the flower (anther and filament)

Sepal

protects the bud

Stigma

receives the pollen from the visiting pollinators

Filament

supports the anther

style

leads the pollen down to the ovary

pistil

The female reproductive part of the flower (stigma and style, ovary)

petal

Bright and colourful to attract pollinators

ovary

to prepare ovules for fertilization

Anther

Creates pollen

cell

A basic unit of structure and function in an organism.

tissue

A group of cells that work together to perform a task.

organ

Two or more tissues working together to perform a task.

organ system

Organ that work together to perform a task.

Organism

a living thing

nucleus

The command center of cells. it contains our chromosomes and genetic information needed for the reproduction of life. (DNA)

Endoplasmic reticulum

Works closely with ribosomes to produce and deliver important cell products.

cell membrane

a very thin layer, composed of lipids and protein, that surrounds the cytoplasm of a cell and controls the passage of substance into and out of the cell

mitochondria

The powerhouse of the cell - it takes the food we eat and converts it to energy for cell activities.

organelles

specialised structured within a living cell.

vacuoles

Used to store different substances. Are larger in plants than animals

ribosomes

makes proteins

Golgi bodies

packages products to deliver to the cell.

Nuclear membrane

surrounds and protects the nucleus

Nucleolus

it is responsible for making ribosomes and it is found inside the nucleus

cell wall

The outermost layer of cells in plants, that gives shape to thee cell and protects it from infections.

cytoplasm

The jellylike material that makes up much of a cell inside the cell membrane

cytosol

Used to describe the liquid within Cytoplasm and all the organelles suspended within it.

chloroplast

contains pigment (chlorophyll) that allows the plant to photosynthesise

difference between a plant and animal cell

Plant cells
- have a cell wall,
- contain chlorophyll
- have large vacuoles

levels of organisation

cell -> tissue -> organ -> organ system -> organism

digestive system function

A group of organs which work together to covert food into energy

digestive system order

mouth -> oesophagus -> stomach -> small intestine -> large intestine -> rectum -> anus (gum to bum)

The respiratory system function

allows us to breath they bring oxygen into our bodies and send carbon dioxide out

Respiratory system order

Nasal passage -> larynx -> trachea -> bronchi -> bronchioles -> alveoli

why does the oesophagus work upside down

the muscles in our esophagus constrict and relax, which is called peristalsis and pushes food along the esophagus and into the stomach

Circulatory system function

The circulatory system is made up of blood vessels that carry blood away from and towards the heart.

Diaphragm function

Upon inhalation, the diaphragm contracts and flattens and the chest cavity enlarges. This contraction creates a vacuum, which pulls air into the lungs.

Reproduction system function

To generate offspring's to continue the existence of a species

Physical and chemical digesetion

Cell theory

1) All organisms are made of cells.
2) All existing cells are produced by other living cells.
3) The cell is the most basic unit of life.