Biology Term 2

Eukaryote

Eukaryote

A cell that contains a nucleus and membrane bound organelles.

Prokaryote

A unicellular organism that lacks a nucleus and membrane bound organelles.

What is the cell theory? (3 parts)

1. All living things are made up of cells. 2. Cells are the basic units of structure and function in living things. 3. New cells are produced from existing cells.

Unicellular

Made of a single cell

Multicellular

Made up of more than one cell.

Examples of eukaryotic cells

plants, animals, fungi

Examples of prokaryotic cells

Bacteria and Archaea

Cytoplasm

A jellylike fluid inside the cell in which the organelles are suspended.

Ribosomes

Makes proteins.

cell membrane

Thin, flexible barrier around a cell; regulates what enters and leaves the cell

List membrane-bound organelles found in eukaryotes but not in prokaryotes

Nucleus, mitochondria, golgi apparatus.

What are organelles?

Tiny organs. They work together for the cell to function.

cell wall

A rigid structure that surrounds the cell membrane and provides support to the cell.

Where is the cell wall found?

Plant cells, outside the cell membrane.

Nucleus

The nucleus can be considered 'the brain' of the cell. It controls all cell activities, and inside it, it has a nucleolus, which produces ribosomes. In case of eukaryotes, the nucleus contains genetic material such as DNA. While prokaryotes also contain DNA, they may not necessarily have a nucleus to store it in. Attached to the nuclear membrane, you can find the Endoplasmic Reticulum.

Endoplasmic Reticulum

A cell structure that forms a maze of passageways in which proteins and other materials are carried from one part of the cell to another. It is attached to the nucleus.

Golgi apparatus

A system of membranes that modifies and packages proteins for export by the cell.

Mitochondria

An organelle found in large numbers in most cells, it is the powerhouse of the cell.

Difference between plant and animal cells

Plant cells have larger vacuoles, chloroplasts and cell walls, while animal cells do not.

Vacuole

Within the cytoplasm of a cell, a cell organelle that stores materials such as water, salts, proteins, and carbohydrates.

Chloroplast

Organelle found in cells of plants and some other organisms that captures the energy from sunlight and converts it into chemical energy.

Chlorophyll

Green pigment in plants that absorbs light energy used to carry out photosynthesis.

purpose of digestive system

The digestive system breaks down food into nutrients such as carbohydrates, fats, and proteins. They can then be absorbed into the bloodstream so the body can use them for energy, growth, and repair.

Teeth role in digestive system

The teeth break down food using the method of mechanical digestion with the help of saliva in the mouth, which has enzymes that also help break down food using chemical digestion.

Parts of the digestive system

mouth, oesophagus, stomach, liver, gall bladder, pancreas, small intestine, large intestine, rectum, anus.

What does the oesophagus do?

The oesophagus is the long tube through which food is transported from the mouth to the stomach. The rhythmic contraction of the muscles in the digestive system is called peristalsis. The oesophagus doesn't play any role in mechanical/chemical digestion and is there for only transport.

mechanical digestion

Part of digestion that uses movement and muscles to break down food

chemical digestion

Process by which enzymes break down food into small molecules that the body can use

stomach role in digestion

The stomach is similar to a hollow bag. The digestive juices it produces are a mix of amylase and enzymes which help break down food. This is chemical digestion, while when it churns and mixes food, it is mechanical digestion.

What is amylase produced by and where does it act?

It's produced by salivary glands and pancreas and acts in the mouth and small intestine.

What is pepsin produced by and where does it act?

Pepsin is produced by and acts in the stomach.

What is lipase produced by and where does it act?

Lipase is produced in the pancreas and acts in the small intestine.

Liver function in the digestive system

One of the liver's many functions is to produce bile, which mixes with food in the small intestine to help dissolve the fats in the food for easy absorption. It also neutralises stomach acids.

Purpose of pancreas in digestive system

The pancreas produces enzymes to help digest food (chemical digestion). It pours enzymes into the food in the small intestine.

Purpose of small intestine in digestive system

The small intestine is where majority of the digestions takes places. Most nutrients are absorbed through the walls of the small intestine into the bloodstream to be carried off into the cells in your body.

purpose of villi

Located only in the small intestines, the villi are finger-like folds which increase the surface area of the intestines in order to provide further space for the absorption of nutrients. They help the body create energy faster and transport nutrients to blood vessels, and more places at a time.

Purpose of large intestine in digestive system

All food which has not been broken down until this point reaches the large intestine. This is where water is absorbed and where wastes from your food are stored and treated, ready to be expelled from the body.

Purpose of the rectum in digestive system

Solid waste left moving through the large intestine is temporarily stored in the rectum. It is then excreted through the anus in the form of faeces.

purpose of circulatory system

It circulates the blood, oxygen, nutrients and hormones to all cells of the body, and also transports waste including carbon dioxide and urea, taking them to other parts of the body.

How does the circulatory system work?

Pumps blood through the right chambers of the heart and through the lungs, where it acquires oxygen. From there it is pumped back into the left chambers of the heart, where it is pumped into the main artery (aorta), which then sends the oxygenated blood to the rest of the body using a system of veins and capillaries. Finally, the blood completes the circuit by passing through small veins, which join to form increasingly larger vessels. Eventually, the blood reaches the largest veins, which return it to the right side of the heart to complete and restart the process.

What are the 3 main parts of the circulatory system?

The heart, blood vessels, and and blood.

What is the heart's role in the circulatory system?

It is the muscular pump that moves the blood around your body and is also the cause of your pulse.

What are blood vessels' role in the circulatory system?

The blood vessels help separate and remove carbon dioxide from cells and transport it to the heart to be oxygenated again, and the transported out to the rest of the body. It also transports hormones, oxygen (after going through lungs), nutrients, waste (carbon dioxide, urea) and is part of our immune system.

What is blood's role in the circulatory system?

The purpose of the blood in this system is to oxygenate the rest of the cells in the body, and the blood vessels help with this.

How are the heart and blood vessels connected to allow circulation of blood?

Heart is made of chambers which are muscles that contract and push the blood into the vessels which circulates the blood all over the body.

Types of vessels in the circulatory system

arteries, veins, capillaries.

Describe what happens to blood at the lungs

Blood that is deoxygenated is oxygenated at the lungs. The oxygenated blood from the lungs is then transported to all parts of the body. Waste carbon dioxide is picked up from the cells and taken back to the lungs

pulmonary circuit

System of blood vessels that carries blood between the heart and the lungs.

How many chambers does the heart have?

4 (2 atria, 2 ventricles)

What is the difference between systemic and pulmonary circulation?

Pulmonary circulation moves blood between the heart and the lungs, while systemic circulation moves blood between the heart and the rest of the body.

Name the parts of the heart

Right atrium, right ventricle, left atrium, left ventricle, aorta, pulmonary artery, pulmonary veins, superior vena cava, inferior vena cava.

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 into the aorta

Aorta

The large arterial trunk that carries blood from the heart to be distributed by branch arteries through the body.

pulmonary artery

Carries deoxygenated blood from the heart to the lungs.

pulmonary veins

Carry the oxygenated blood from the lungs into the left atrium.

superior vena cava

Transports blood from the upper portion of the body to the heart.

inferior vena cava

Carries blood from lower regions of the body to right atrium.

Valves

Flap of tissue in the heart and large veins that prevents blood from flowing backwards.

What is the respiratory system?

This system keeps the body's cells supplied with oxygen & removes carbon dioxide as it is released from cells.

Parts of the respiratory system

Nasal cavity, pharynx, trachea, bronchus, lung, alveoli, and lungs.

Nasal cavity

It works as a passage for air to enter the respiratory system and warms and humidifies to air. It also filters out airborne particles. The shape of the nasal cavity makes the air entering ot swirl around.

Pharynx

The pharynx works as an air passage between the nasal cavity and lungs. The vocal cords live here, and further filtration of air occurs. It separates the food which enters into the oesophagus, and air into the trachea

Trachea

The trachea is a tube to move air in and out of lungs. Even further filtration of air happens here and it is held open by C-shaped cartilage.

bronchus

It is a continuation of tube to move air in and out of lungs. and branches out right and left from the trachea to the lungs. It's wrapped in cartilage.

Cartilage

Strong connective tissue that supports the body. It's more flexible than bone.

Lungs

Organs densely packed with sacs that exchange gas. There is one on each side of body. Additionally, the heart sits between lungs.

Alveoli

Tiny sacs of lung tissue specialized for the diffusion of gas across the capillary membrane.

Diaphargm

It is a large sheet of muscle located at the bottom of ribs. When contracted, the lungs expand allowing air to flow in to them. When relaxed, lungs compress squeezing air out.

intercostal muscles

Muscles which move the rib cage during breathing. When contracted, the lungs expand allowing air to flow in to them.

Why do we breathe?

We breathe to get oxygen to our cells for use in cellular respiration and to get rid of the waste gas carbon dioxide.

purpose of blood

to transport oxygen, carbon dioxide, nutrients, hormonesand the waste products of metabolism

Haemoglobin

The protein that carries oxygen in the red blood cells.

Describe the walls and diameter of arteries

thick and muscular walls to withstand high blood, large diameter to allow maximum blood flow

Describe the walls of the VEINS

Thinner and less elastic and carry blood under low pressure

Describe the walls of capillaries

one cell thick and wide; blood flow slow to allow nutrients and waste to pass between blood and surrounding cells

Which artery doesn't carry oxygenated blood?

pulmonary arteries

What is reproduction?

The process by which new individual organisms - "offspring" are produced from by their "parents".

What are the forms of reproduction?

asexual and sexual

Define asexual reproduction

Offspring are genetically identical to a single parent.

Define sexual reproduction

Two parents contribute genetic information to produce unique offspring.

What are the types of asexual reproduction?

Budding, regeneration, binary fission, runners, spores.

Define budding

A cutting of a plant will grow new roots to become a new plant or An organism (eg. Hydra) produces buds that fall off and become new organisms.

Define binary fission

Unicellular organisms like bacteria, divide into 2 new cells.

Define runners

Where plants send out a shoot/runner that lays down new roots to establish new plants.

Define spore

Fungi produce spores that reproduce when they get wet in a warm, dark environment.

Advantages of asexual reproduction

• Reproduction with no mate

• It results in a large no. of offspring rapidly

• Stable environments with very little change are favourable for organisms

• Offspring are identical to parents

Disadvantages of asexual reproduction

• Produced offspring are genetically identical to each other and parent

• This causes little or no genetic variation within a population

• Any mutation in the parent cell, can cause harmful effects on the survival ability of the offspring.

• If any harmful mutation, environmental changes can be deadly to all the individuals.

Define semi-permeable

It lets certain substances in and blocks others out; it's a membrane.

Vacuole purpose in a plant cell

Used for temporary storage of water, waste products, food, and cellular material.

Number of parents in asexual reproduction

one

Number of parents in sexual reproduction

two

Offspring of asexual reproduction are

genetically identical to the parent

Offspring of sexual reproduction are

genetically different from their parents and one another

types of sexual reproduction

Human Reproduction, internal/external fertilisation

Compare an artery and a vein

Arteries: - Carry blood away from the heart, thick/elastic walls, carry oxygenated blood (except pulmonary artery), located deep Veins - Carry blood to the heart, deoxygenated, thin walls, use valves to keep your blood flowing, located superficial Similarities Both are blood vessels/part of the circulatory system

Describe the flow of blood from a cell in your finger, to your heart and back to your finger again. Include key terms/structures.

1. Deoxygenated blood travels back to the heart and enters the right atrium 2) Blood pumped into the right ventricle through the tricuspid valve 3) Blood travels to the lungs to become oxygenated 4) The left atrium received oxygen-rich blood and pumps it to the left ventricle through the mitral valve 5) The left ventricle pumps oxygen-rich blood through aortic valve out to the rest of the body 6) Oxygenated blood returns to cell in finger with oxygen/nutrients and gas exchange occurs

How do the three types of mammals differ in the way their offspring develop?

monotremes, marsupials, and placentals.